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Critical Review of Project Management System for Residential Refurbishment Projects in Hong Kong (HK) – A Case Study in Lift / Elevator Upgrading

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Type of Academic Paper – Dissertation

Academic Subject – Project Management

Word Count – 10935 words

Abstract

This thesis aims to study the use of sustainable materials in the renovation of existing residential buildings in Hong Kong. In particular, the researchers delve into case studies on the refurbishment of elevators in old residential abodes. In the case, two case studies used, the old lift motors used to consume a lot of energy were replaced with energy-efficient regenerative drives. The case studies focused on Sun Chui estate and Hin Keng estate, both of which are located in Hong Kong. The primary data collection method consisted of carrying out interviews with Hong Buildings Department stakeholders. The interviews aimed to establish the position of Hong Kong’s Building Department on the implementation of the incentives to promote the use of sustainable parts in upgrading lifts.

From the two case studies, the regenerative drives outdid the old motors in terms of energy efficiency. From the interview results, even though there were mixed feelings by the Building Department stakeholders, over 80 per cent of the interviewees recommended using sustainable elevator parts in the refurbishment of old lifts. Therefore, it can be concluded that the use of energy-saving devices in the upgrading of lifts will go a long way to cutting down on overall energy usage in residential high-rise buildings, which will be beneficial to both the property owners and the tenants.

Introduction

Residential and commercial building management has gained importance in Hong Kong after several building-related incidents such as tragic fires, falling of building fabrics and an outbreak of severe acute respiratory syndrome. For sustaining a safe and healthy environment, the local government of Hong Kong has taken the initiative by launching consultative approaches to ensure that a culture of building management and maintenance can be introduced both at the local and community level (Yau & Ho, 2009).

Being a physical asset, a property is bound to wear and tear hence it requires proper management and maintenance which is significant to keep the building in good and serviced condition (Gillingham et al., 2009). Moreover, the government also suggested appointing external property management agents (PMA) for managing the building on their behalf and keeping up the physical condition of the building by applying routine maintenance procedures. Hence, it can be suggested here that there is a definite need for an efficient project management system that must be adopted for the residential refurbishment of the projects in Hong Kong.

In Hong Kong, a considerable proportion of the residential buildings have poor façade maintenance; hence buildings get damaged by climate and application of old standards. The process of evaluation, re-designing and refurbishments of a structure involves various activities/processes, and covering all these is out of the scope at this level. Hence the focus of the researcher will be on elevators/lifts. The first scope of service in this particular work field includes the evaluations and review of the specification, followed by the devising a plan for concrete repair of work or upgrading the elevators. In the second step, the proposed alterations are initiated by the building regulatory requirements.

The Rationale of the Project

The Hong Kong Housing Authority (HKHA) presently manages a residential housing stock of more than 750,000 apartments; homes for over three million individuals. Propelled by policy requirements of the refurbishment of old residential buildings.  This is the quest to optimise the utilisation of public housing. The HKHA instituted the Comprehensive Structural Investigation Programme, otherwise referred to as (CSIP), to refurbish old residential houses. The CSIP is the first initiative in Hong Kong that thoroughly examines aged premises’ structural status to determine the causes of susceptibility to deterioration, defects, and long-term housing performance, based on the kind of sustainable refurbishment solutions used. The CSIP helps in creating win-win solutions that enable sustainable retrofitting of aged buildings. The HKHA works hard to share with the construction industry its experience and skills acquired from the CSIP, for instance, research techniques, the outcome, and its creativity in the redevelopment and refurbishment schemes, to improve the long-term residential property sustainability.

Residential housing in HK has a long history that traces back to the early 40s. The HK Government developed the first resettlement estate to shelter over 55,000 people who had been left homeless after the Shek Mei fire in 1953. Leveraging this programme’s accomplishment, a colossal construction initiative was rolled out to offer affordable residential houses for low-income earners.

The HKHA currently manages over 2,000 residential premises housing more than three million families. Previously, the major policy of the HKHA on old houses was demolishing the aged buildings and developing new ones. Considering the massive drain of land resources in HK, combined with substantial human and financial capital required for redevelopment, and the increased environmental consciousness, the HKHA has shifted to a sustainable way of refurbishing old buildings to optimise the utilisation of existing houses.

Chan et al. (2015) define sustainability as the capacity to address today’s needs without endangering posterity. Over the last ten years, substantial research interest in green residential houses has significantly contributed to environmental consciousness on all fronts; construction technique, design methodology, and energy efficiency. Most of the research outcomes have been applied in the construction industry leading to sustainable buildings with mitigated carbon footprints and durability. Whereas the construction HK industry is moving in the right direction for new buildings, it should not be forgotten that new residential properties in a highly sophisticated city like HK only accounts for a small segment of the sustainability challenge. As a matter of fact, the number of newly developed residential apartments of all kinds in HK was only 25,000 units in 2013, translating to a mere 1 per cent of the 2.5 million existing apartments. Regarding residential abodes, the HKHA developed about 13,000 apartments between 2014 and 2015. However, the number still represents less than 2 per cent of the old family housing units. Therefore, HK’s construction sustainability cannot be implemented without a green strategy of refurbishing residential units.

Numerous green programmes can be used for a new residential home leading to energy-efficient abodes. Still, the destruction and replacement of existing buildings are, nevertheless, an energy-consuming venture. Given these facts, neither building new houses nor implementing redevelopment strategies can be considered a sustainable way of solving the masses’ shelter needs. Thus a most sustainable approach would be to utilise modern project management systems to refurbish the existing residential buildings.

More than 87 per cent of the residential units in HK are flats with more than three storeys. Out of these, 19 per cent of the flats either have dilapidated staircases/lifts/elevators or are unsustainable, energy-wise, or in environmental terms. Upgrading of staircases and elevators/lifts constitutes one of the primary refurbishing components of family homes in HK.

The rapid urbanisation of modern infrastructure provides comfort on one side while it also creates problems. Although there are new opportunities identified for building new structures, towns, and societies, architectural planners must still consider the concepts and importance of sustainability, environment, and heritage (IEA, 2010). The government and industry stakeholders should define building control procedures that help control the new developments and encourage maintenance of the quality standard of old structures; to retain the local heritage and style of society at large. The process reduces wastage and enhances sustainability as well as the safety of the built structure. Hence, the project management system and the residential refurbishment process optimisations can play a significant role in the economy of HK and the overall built environment.

Research Aim

The primary aim and objective of this research project are to apply project management system techniques in the upgrading of lift/elevators while ensuring that the modernization process of the elevators meets Hong Kong Building Department requirements. In particular, the study aims to utilise project management techniques to replace traditional motors in old elevators with regenerative devices that are highly efficient and cost-effective. The research plans to achieve this by undertaking 2 case studies on lift upgrading projects in Hong Kong residential buildings, emphasising DC motor replacement with sustainable ones. The researcher then aims to suggest/recommend an optimised method/mechanism that can be utilised by the practitioners working in refurbishment projects, especially on the refurbishment of lifts/elevators. 

Research Question

The primary research question to be addressed in this study is:

   – Is there an optimised method to undertake the refurbishments/upgrading of lifts, which is in line with the local building requirements of HK?

This research question will be addressed by completing the following aims and objectives:

  • Review and analyse the current building regulations related to refurbishments, especially for lifts/elevators
  • Review and analyse the best methods that can be used for the above process, globally.
  • Undertake case studies, find out how the lift upgrading is being completed, and suggest if they fulfil the existing building regulations.
  • From the results obtained and the literature reviewed, will hopefully suggest how this process must be accomplished. This includes suggesting how costs can be saved by opting for lift repairs instead of their complete replacement with new ones.

Note: In the form of primary research, the comparison of two cases of Hong Kong residential area will be completed (to gain qualitative and quantitative data) and discussed along with the proposed residential refurbishment model, which will help in clearly understanding the project scope.

Identified Problems

  • This research will investigate the possibilities of introducing project management systems in lift refurbishments in old residential buildings.
  • The idea being adopted is to introduce sustainable lifts that are super-efficient and cost-saving in energy consumption.
  • Lift upgrading will be performed to provide residents living in high-rise residential buildings with direct lift access on every floor along with improved and fast lift services.

Benefits of Refurbishment; Upgrading of Old elevators

  • Nowadays, builders and designers are using refurbished sustainable retrofits such as elevators because this approach saves on costs.
  • Sustainable modernization of elevators can greatly cut down on energy costs which is beneficial to both the landlords and their tenants.
  • The timeframe required for repair or upgrade old elevators is shorter than the time it would take to replace old elevators with new ones.

Project Management System

  • An efficient project management system must be introduced to cope with present building requirements and upgrading old elevators to comply with requirements stipulated by the regulatory authorities.
  • An understanding must be established regarding project management as to how it can help make a project successful and for increasing success rate in elevator upgrading.
  • Moreover, it will be required to introduce the concepts to the managers who will be working directly on the refurbishment projects as they are the ones who will be applying these techniques on site.
  • Further, it will be required to identify and outline the proper project exit strategy and the extent to which the project can be extended in the future.

Literature Review

Theoretical Framework

To get a better understanding of this study, the fundamental theory will be presented in this section. The theory is considered relevant to answer the research questions stated at the beginning of this paper.

Early Phase in Refurbishment Projects

Refurbishment industry is comprised of the most important sectors in many developed countries (Rhodes 2015). Concerning work on existing buildings, more than 20 expressions are used with almost the same meaning to describe attempts to redress depreciation effects (Edum-Fotwe & McCaffer 2000). Refurbishment, renovation, rebuild and upgrade are just some of them. The European Standard uses the following definition of refurbishment; “Amendment and improvements to an existing structure to bring it up to a liveable condition”(Toor & Ofori 2008)In this paper definition of refurbishment has been used to cover the whole range of terms; “Refurbishment refers to enhance, major repairs work, renovations, alterations, conversions, extensions and modernization of the existing building, but exclude routine maintenance and cleaning work.”

When refurbishing a building, there are several reasons to do it sustainably. Some of the benefits of sustainable refurbishment are that it can preserve the existing built environment and protect future generations. Sustainable refurbishment also contributes to a reduced environmental footprint and better adaption to climate change (Kent & Becerik-Gerber 2010).

A common widely accepted definition of “Sustainability” is; “Improving the quality of human life while living within the carrying capacity of supporting ecosystems”(Johansen & Walter 2007)While “Sustainable Development” is by the United Nations (UN) defined as: “Development that meets the needs of the present without compromising the ability of future generations to meet their needs.”(Toor & Ofori 2008)In these two definitions, the quality of life (social) and the ecosystem (ecological) seem to be the main focus. The economic aspect is however not specified. According to the Brundtland Commission (Kent & Becerik-Gerber 2010), the three main sections within sustainable development is; economic, social end ecological. The sustainable refurbishment has the same main foundation as sustainable development. When refurbishing a building, the ideal will be to focus on the interaction between the three main pillars of sustainable development.

Stairways into buildings have been reported amongst the most challenging environmental barriers for users of wheeled mobility devices(Kent & Becerik-Gerber 2010). Further, older adults have identified stair climbing as most requiring assistive devices (Ng 2009). The significance of this problem should not be underestimated. Reporting on findings from the National Health Interview Survey and the Census Bureau’s Survey of Income and Program Participation, Poon et al. (2004) note that approximately 1.9 to 2.5 million people in the US use wheeled mobility devices and an additional 6.1 million individuals use other devices, such as canes, crutches, or walkers. Quoting statistics from the National Center for Health Statistics 2006, Maisel also notes that 11.5 million persons aged 70 and older reported difficulty climbing ten steps without resting (Lee 2014).

With estimates of home inaccessibility as high as 90% in the US (Ho et al. 2012), home access presents a significant barrier to people with mobility impairments and those wanting to age-in-place (Hui et al. 2011). Traditional solutions to addressing home inaccessibility have typically involved either moving to alternate housing or modifying the home to remove accessibility barriers (Chan et al. 2015). The complex challenges associated with a move and the failure of many to adequately modify their homes (Wong et al. 2012)have serious implications for people with mobility limitations. Inaccessible housing has been associated with premature institutionalization, increased care costs, deteriorating health and well-being, dislocated family relations, and recourse to higher dependency housing (Latiffi et al. 2013).

Home access solutions (HAS) aim to address the architectural barrier that stairs present and allow users to safely enter and exit the home while maintaining as much independence as possible (Karimiazari et al. 2011). Existing HAS range from relatively inexpensive handrails and ramps to more costly elevators and lifts. Lifts can be categorized into three broad groups: 1) vertical platform lifts – designed to transport the user vertically between 2 or 3-floor levels; 2) inclined platform lifts (also referred to as a wheelchair platform lifts) – designed to transport the user between levels on an incline such as along a stairway; and 3) stair glides (also referred to as stairlifts, stair-chair lifts, and stair climbers) – designed to transport a seated user between floor levels while travelling on an incline such as along a stairway (Ortiz et al. 2009). It is apparent that innovation in HAS over recent years is limited; the changing demographics have done little to spur innovation in this area. These ‘traditional’ HAS that have been used for many years continue to dominate the market. While a few new solutions have been developed in recent years(Hwang & Bao Yeo 2011), these solutions’ uptake is limited to specific niche applications.

Studies looking at the benefits and limitations of ‘traditional’ have several drawbacks with these solutions. While ramps typically offer a lower cost access solution, their large footprint and impact on home aesthetics limit the locations in which they can be used and reduces their desirability for many (Sambasivan & Soon 2007). Safety concerns such as the grade of the ramp challenges negotiating tight ramp corners, and the effects of weather on-ramp slipperiness have also been reported (Begum et al. 2007). Elevators have been identified as effective solutions regarding speed, capacity, rise and usability. However, the need for adequate space and the high costs associated with their purchase, installation, and maintenance are significant drawbacks, limiting their use in typical home settings (Prasath Kumar et al. 2016). Platform lifts and stair glides remain the ‘devices of choice’ for small elevation changes (Karimiazari et al. 2011) in existing homes; however, these also have their limitations. For platform lifts, limitations relating to use, size, speed, capacity, and rise have been identified (Johansen & Walter 2007). For stair glides, the need to transfer on and off the chair (often at the top of the stairs- one of the most dangerous places in a house) poses risks for those with the transfer, balance or visual limitations (Edum-Fotwe & McCaffer 2000), and the fact that they do not provide access for wheeled mobility devices limits their usability for many (Sambasivan & Soon 2007). Also, anecdotally, stair glides do not provide quality access, marginalising individual dignity with their slow, cumbersome use.

Two other significant drawbacks inherent with existing HAS are their lack of inclusivity and the fact that they appear to many as obvious symbols of disability. These have been reported to negatively impact residents’ self-identity and their relationship with neighbours and make residents feel less secure, even vulnerable (Latiffi et al. 2013). It has been suggested that these factors may compromise the functionality and expected benefits of HAS (Ortiz et al. 2009).

This work aimed to address some of the drawbacks of the existing HAS by developing a new solution- the ARISE integrated staircase lift. This novel design aims to: address inclusivity by providing a staircase and lift in the same access location and footprint; encouraging stair use whenever possible (e.g. by seniors for exercise), as well as offering the safety and convenience of a lift when necessary (e.g. when the person is encumbered or using a wheelchair); and provide repeatable emergency descent from a house in times of power outages. The device allows for the use of stairs or the lift to access the same entrance, whether walking, using a wheelchair, using a walker or pushing a stroller.

Sustainable Refurbishment

According to the theory of reasoned action, the performing behaviour is determined by the intention which can be predicted by one’s attitude and subjective norm (Latiffi et al. 2013). It is not uncommon for owners and occupants of sustainable residential refurbishment projects to stay in their property while work is carried out. Therefore, it is sensible to get the owners and occupants involved in the decision-making process (Pries & Dorée 2005). Occupants’ norms, attitudes, and intentions towards residential energy consumption would inevitably affect any sustainable refurbishment scheme’s success. A small change in occupant behaviours, e.g. by lowering the indoor temperatures, using energy-efficient light bulbs, turning off the lights when leaving a room, changing the hours of occupation, adjusting the ventilation rates, using various Energy Usage Systems (EUS) for cooking, switching off unused electrical appliances, etc. could lead to a sizeable reduction in energy consumption(Faridi & El‐Sayegh 2006). On the other hand, innovative technologies and materials and advanced building services systems may also help cut down on energy consumption. Sustainable refurbishment methods can be classified according to different building components, building functions, technical or non-technical aspects, etc. As discussed in the preceding section, not all sustainable refurbishment methods apply to Hong Kong. To determine which sustainable refurbishment methods are relevant to the local context, it is necessary to identify suitable criteria to assess those methods’ suitability. Amongst other aspects, the climatic condition (Hanus & Harris 2013) and seasonal variations were considered influential. Besides, the building usage and owners and occupants’ behaviour, could also lead to a variation in energy demand. Therefore, five factors were used to determine the suitability of sustainable refurbishment methods, and they include climatic condition, user pattern in energy consumption, relevancy to residential building, suitability for being applied in high-rise construction (Tucker 2007; Johansen & Walter 2007; Edum-Fotwe & McCaffer 2000; Hwang & Bao Yeo 2011), and other building characteristics. While high-rise buildings in Hong Kong are owned and occupied by different people, it is never easy to have a consensus in sustainable refurbishment decisions except for retrofitting, i.e. one of a comprehensive nature and large scale (Eccles 1981). However, individual owners and occupants could also initiate sustainable refurbishment initiatives at different times. According to Rhodes (2015), refurbishment can be divided into light touch or refresh, medium intervention, extensive intervention, comprehensive refurbishment and demolition. On the other hand, Hwang & Bao Yeo (2011) opined that sustainable refurbishment could be in the form of a whole dwelling approach or an element by element regime to minimise the disturbance brought by refurbishment. In this research, sustainable refurbishment is divided into three types, namely: minor upgrading, medium scale improvement and major refurbishment. To examine as many possible sustainable refurbishment methods as possible, a major refurbishment was chosen as the study subject. In Hong Kong, major refurbishment is mandated for those over 30 years old, and the purpose is to uplift the building condition and maintain a safe living environment (Razak Bin Ibrahim et al. 2010; Toor & Ofori 2008; Prasath Kumar et al. 2016). It would be the best opportunity to integrate the sustainability measures in the major refurbishment scheme.

Sustainable elevator systems; Reduction of Waste through Prefabrication

In their study, Ma & Wang (2009) define Prefabrication as the manufacturing process, which occurs in a specialised place where different materials are combined to generate a component segment of the ultimate product. Elevator systems made from prefabricated materials in HK is durable and sustainable, according to Ng (2009). The first prefabricated staircase was introduced in HK in the late 80s. Since then, the HKHA has approved the use of precast materials, since they are reusable and environmentally sustainable. In 2012, prefabricated materials accounted for 28 per cent of the concrete volume utilised in refurbishing residential flats (Zhong et al. 2015). In HK, prefabricated elements are mostly used in making durable facades, slabs, walls, and more recently, it has been used in refurbishing staircases and elevators in residential houses.

According to Li et al. (2014), refurbishment projects increases the application of precasting elements to 60 per cent, including prefabricated living rooms and structural walls. On the contrary, private businesses still depend on old building methods involving timber formwork. Even though prefabrication may be used in some private developers in HK, it is on used to a limited extent (Li et al. 2011; Zhong et al. 2015; Wong et al. 2003; Li et al. 2016; Hui & Or 2005; Jaillon & Poon 2010; L Jaillon & Poon 2009).

In Hong Kong, the building refurbishment sector utilises and generates substantial staircase upgrading materials and waste. For instance, in 2011, about 31 million tonnes of refurbishment waste were produced, out of which 15 per cent was deposited in landfills and 85 per cent in residential filling areas. Recently, the construction of unwanted materials represented about 40 per cent of the entire intake at landfills. At this rate, the landfill capacity will be depleted within 20 years (L. Jaillon & Poon 2009). It is thought that the temporary landfills bank will be exhausted by 2035.

Before 2010, construction waste disposal used to be free of charge; the HK government would pay for its disposal. The cost of disposal for the entire landfills was about HK $6000 M, while the total maintenance expenditure was over HK$ 500 M per year. From 2011 going forward, a disposal fee was introduced. The current charges are HK$200 per tonne for landfills, HK$150 per tonne for residential facilities and HK$50 per tonne for residential fill reception units. With cutting down on waste generated from refurbishment projects, a lot of money can be saved regarding material cost, disposal of concrete waste and the expenditure incurred in waste transportation.

In 2012 the HKHA in its report recommended the use of prefabricated material in upgrading staircases in old residential houses. Besides was precast materials were also recommended as a panacea to construction waste issues due to traditional construction and the utilisation of timber material. Some of the large contractors follow waste management strategies and waste mitigation measures on construction sites.

Since 2000, the HK government has been promoting the use of reusable materials derived from refurbishment waste. In a study conducted by Poon et al. (2013), on a refurbished residential flat that produced about 1 M t waste, 80 per cent of the material proved useful in upgrading the building’s dilapidated staircase.

On the other had the HK government has also introduced incentive programmes to spur contractors to include green features in renovating high-rise residential abodes. According to Profile (2006), the prefabricated staircase is a sustainable feature in refurbishing old premises.

Whereas the previous studies have acknowledged waste mitigation as beneficial when employing prefabrication techniques, quantifying the waste reduction rate needs to be a parameter. Reduction of waste during the staircase upgrading can be achieved by reusing some of the wastes generated materials during the refurbishment process. A study conducted by Yung & Lee (2012) reported that the primary causes of waste during the refurbishment of existing houses were the demolition of the dilapidated staircase. The same authors also report that another cause of waste during the renovation phase is the destruction of timber materials.

The prefabrication method involves both initial decisions in the construction process and waste reduction during renovation activities. Chiu (2007) reported an 80 per cent reduction in in-situ concreting by employing volumetric precasting elements, and also 80 per cent reduction in renovation works on-site. Yong Hu & Chou (2015) demonstrated that wooden formwork comprised the major source of construction waste in HK, representing 40 per cent of the total waste. Furthermore, wet wastes from refurbishment work such as upgrading of staircases accounted for about 30 per cent of the total waste. Ng et al. (2014) contend that the application of prefabrication technology in upgrading residential staircases significantly cut down on waste generated from timber staircases by 73 per cent and 58 per cent, respectively. However, Wong et al. (2014) do not agree with the above study’s outcome, arguing that it was limited to only three building projects in HK. The same authors criticise the study by Ng et al. (2014)  as lacking a benchmark on wastage level. Wong et al. (2014) describe wastage level as the remnant of delivered materials after utilising construction projects. Nevertheless, these waste materials may be reused in modernising residential staircases. Conversely, a study carried out by Wong et al. (2014) revealed that a wastage minimization of up to 90 per cent was attained through prefabrication of old staircases when compared to conventional construction. Accordingly, this study only analysed only two building trades, hence not representative of the entire premises.

Relatively few studies have measured construction waste production in old residential houses in HK or evaluated the project manager’s attitude towards waste minimisation and prefabrication. Therefore, one of the primary intentions of this study is to close the gaps in the knowledge on the application of prefabricated materials in residential refurbishment projects, especially regarding modernising staircases in Hong Kong and prove its effect on waste reduction. Besides, this paper is to analyse the building regulations in HK regarding waste minimisation in refurbishment projects. There is also the need to assess the use of precast elements in renovations buildings, measure its advantage regarding waste minimisation, and compare studies between prefabrication techniques and conventional construction methods about staircase upgrading of existing residential abodes.

Use of Daylight Sensors in Upgraded Stair Cases

Daylight and motion sensors have been previously intergraded with the staircase to reduce electricity usage in commercial buildings when there is no luminance. In Hong Kong, the sensors could be used in a residential high-rise building with open corridors. However, it should be noted that motion sensors are restricted by the HKHA safety codes, which requires that all the staircases have lights on during nighttime. Even the HKHA has designed, and applied lighting systems with motion detectors in staircases for newly developed houses, utilising this technology to existing residential homes is not yet a popular concept. The installed time switches can go a long way to improving energy efficiency by curtailing building services tools’ daily activity time. For instance, Yung & Lee (2012) recommends that some of the elevators for high-rise residential towers be switched off after midnight to minimise energy wastage.

Upgrading Residential Units with Sustainable Elevators

Much of the “green” campaigns focus on minimising energy usage. According to Zhang et al. (2011), residential buildings consume approximately 50 per cent of HK’s energy, out of which elevators account for 10 per cent of high-rise buildings’ energy usage. During peak consumption hours, lifts have been reported to consume up to 43 per cent of the premises’ energy (Chen & Ni 2014). Cheung et al. (2014), explains that daily there are over 8 billion elevator trips taken in storeyed buildings worldwide. Given this fact, energy-efficient elevators will cut down on energy consumption remarkably. Good enough, modern technologies and best approaches involving regeneration converters, motors, manipulation software, and enhancement of counterweights and using light cable lifts can significantly reduce energy consumption. Numerous studies have shown that no elevators save energy consumption by about 39 per cent than residential buildings using older lifts (Wong et al. 2012). Researchers Ng et al. (2014) write of the latest ThyssenKrupp elevators’ latest examples that save energy and space by 28 per cent and 34 per cent respectively. Research on energy optimisation carried out by Chan et al. (2015), and colleagues have revealed that significant energy efficiency potentials exist for modern lifts. Ng et al. (2014) also suggest that by improving the energy consumption in existing and new lifts, elevators can significantly contribute to energy and climate targets in Hong Kong. Research studies on energy utilisation by older and modern elevators are currently being conducted to evaluate contemporary technologies’ value (Ng et al. 2014). These benchmarks offer measured parameters and computations every year for various lifts and provide the data based on the diverse energy consumption of old and modernised elevators.

Nevertheless, research by Chan (2015) reports that a lack of understanding about “green” escalator technologies has delayed the full application of these systems. This part of the reasons why this paper intends to bridge the gap and enlighten architects and contractors on how to utilise the power of these modern technologies in refurbishment projects. According to Yiu et al. (2013) regarding elevator technologies there exists energy-optimised hardware and energy-optimised software. Wong et al. (2014) research reveal how escalators have been responsible for revamping modern towns by moving large masses of individual and operation into smaller areas, leading to vibrant communities. Regarding space conservation, the lift’s role has been more significant than that of the vehicles in changing 21st-century cities. Whereas automobiles have expedited horizontal growth of towns and regions, escalators have made it possible for many persons and human operations to be concentrated in a smaller area. New frontiers in escalator technologies are likely to further modernise cities by facilitating high-rise residential buildings (Ho et al. 2012). Besides explaining the importance of upgrading lifts in refurbished residential flats, this study also aims to recommend the best practices for applying sustainable elevators. Modern inventions lead to the application of energy-saving elevators that use less energy and generate clean energy. Several researchers have called for investment in creative research and the design of “green” elevators. The term ‘sustainable’ has become a radical and dominant development philosophy. With many building refurbishment products being advertised using a “sustainability” angle, recent studies have provided crucial information to help make “sustainable” choices when it comes to upgrading elevators in residential flats.

By the end of this study, contractors and other stakeholders may find the outcome of this paper. It will contain essential recommendations on the best practices for the upgrading of elevators in residential units. According to Jaillon & Poon (2008), the Hong Kong Government has limited codes that give incentives to adopting “sustainable” elevators. Similarly, Ho et al. (2012) have argued that restrictive building regulations in some nations, including Hong Kong, are usually an impediment to implementing sustainable, modern, escalator technologies. Lee (2014) contends that the HK Government should think about financial incentives, possibly in the form of tax breaks, for the application of sustainable elevators during the retrofitting of old residential units.

Hong Kong Building Regulation; Staircases and Elevators Upgrading

The Hong Kong Government Building Department approves staircases lifts and escalators as basic means of transportation that people use every day. The Building Department (BD) controls the design and installation of lifts and elevators in Hong Kong (Wong et al. 2011). Before upgrading a lift/escalator, the BD requires that the refurbishment contractor RC has approval from the Area Director responsible for lift/elevators and safety gadgets used for the facility.

The BD stipulates that if there is any form of upgrading to be done on the staircases lifts or elevators, the contractor is obliged to notify must notify the Director of the upgrading plans and apply for a re-appraisal.  The BD Director has the authority to either approve or reject the application on many factors (Poon et al. 2004). The staircase, lift or elevators approval permit covers any changes in management and operation mode accordingly.

The RC must understand that new approval of the application has to be made should there be any change of the operating distance or inclusion of safety peripherals that are not stipulated in the safety code. Most of the elevators are usually retrofitted in a building or form a component of it. The BD stipulates that careful attention should be accorded to the lift/excavator’s loading capacity to ensure that the equipment complies with safety standards.

Project Management Systems.

The Research on the Integrated Management Systems During the Elevator Upgrading Phase

The elevator upgrading phase of the construction project is complex as it requires a lot of financial expenditure, resources and participants. It is essential to effectively integrate the project management functions in the elevator upgrading phase, optimising the realisation of project objectives and the development of late-operation.

The Concept of Integrated Management During the Elevator Upgrading Phase

The integrated management of the construction project during the upgrading phase is targeted to the project’s elevator upgrading phase and plan, organise, guide and control project efficiently through a temporary special soft organisation, and achieve the organic integration of management functions during the upgrading phase. It will achieve comprehensive coordination and optimisation of dynamic management and project objectives during the upgrading phase, thereby enabling the project’s implementation in the best operating condition to produce optimal results in a relatively short period.

The Research on the Integrated Management Model During the Elevator Upgrading Phase

There are three general contracting modes ruled by “Construction Laws”: the general contract of the entire process, the single overall contract, and the multiple general contracts. There are four general contracting modes: EPC, the general management contract, the general design contract, and the general construction contract. We recommend using the single overall contract management model during the upgrading phase, which is advocated by the “Construction Law” and is internationally recognised. It uses the total design contract and professional design subcontracting system and the total construction contract and professional construction subcontracting system. This model can be more convenient for integrated optimisation management. The integrated project management model will dynamically contact all work in upgrading and optimising them mutually. It can also reduce the cost in the entire construction process for greater savings in construction investment and greatly increase the control capabilities of funds.

The Integration of Seven Management Functions During the Elevator Upgrading Phase

To improve the management of the elevator upgrading phase in a modern construction project, it must build a multidimensional management system with all management functions and integrated control. The key is to capture various elements (project management functions) in the integrated system. The seven major management functions of construction projects during the upgrading phase are progress management, cost management, quality management, contract management, environmental management, occupational safety management, information management, as shown in the figure.

Figure 1 Seven Major Management Functions of The Building Phase

(1) The integrated management of seven management functions

Information integration is the key to integrated management of the construction project. To achieve information integration, information identification and the systematic code is the prerequisite (Hedre 2009).

Identification of Information   Construction project information should be classified and unified by the classification principles of project information. When a new piece of project information is brought to the project department, the information manager should identify the information and extract its elements efficiently, for example, type of documents, index of information, the timestamp of access, the deadline of feedback, etc. These are all information elements of constructing an integrated list, which is equivalent to the information index. In the integrated system that will be established afterwards, these information elements are the query’s approach and base. Therefore, identifying and extracting information elements are essential parts of the proposed system.

Unified Coding of Information   It’s the key to solving the Information Isolated Island problem to establish the unified coding system of project information. With this system, the communication and exchange of information could be truly realised, and then the integration of information could be realised.

Some countries are carrying out the information integration of the community and international construction projects, to establish a construction information classification system (CICS) as the information centre during the project’s lifetime. Nowadays, many countries have begun to use these systems, for example, a unified system has already been used in North America, but there are still no unified China standards (Hwang & Ng 2013). This paper’s coding principle is by “Beijing construction information management” and the actual coding method in construction to explain the management ideas and intentions of project integration

 

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Methodology

This chapter delves into the techniques used to address the research questions, aims, and objectives discussed in Chapter 1.

Research Design

Using a case study, this research aims to produce solid and reliable knowledge of residential refurbishment projects in Hong Kong. It is a research approach that offers an opportunity for discoveries from practical observation of real-life situations. According to Rowley (2002), case studies came about due to the desire to know complex social phenomena. Case studies were previously limited to the field of Law. Still, nowadays, the research strategy is popularly used in business, sociology, and project management among so many other fields. Due to the broad application, there exist numerous definitions for a case study. In design research, case study, many of the times refers to a project tied to a particular theme or a subproject. This is similar to how the case study is defined in business, where a whole business is considered a case study.

When using a case study as a research strategy, caution should be taken not to label the study a case study, but carefully show the survey’s limits and put it in the right context (Darke et al. 1998).  Kenley (2010) proposes that a scholar needs to revise and refine the research thoughts while conducting the research to create limitations and succinctly show the difference between the main subject and the delimiting context. This is known as casing and is usually the final thing done during research, and maybe the most significant result of the investigation. Some researchers have also come up with comparable definitions.  Bent Chen et al. (2009) posits that the crucial factor in describing a case study is choosing what to study and delimiting what has been chosen for study, referred to as casing.  A case study can preserve the complete and essential characteristics of everyday and current events that distinguish it from research studies, for instance, history or experimental studies. Since differences may exist in these studies’ scope, these differences are not significant as all studies may explore or explain phenomena. Dave & Koskela (2009) see case studies as a specific method of describing cases and does not involve analysis or looking for causal relationships. In the real world, demarcations separating phenomena and their contexts are hard to determine; this may lead the researcher to focus more on the related circumstances.  Using a case study, we can get explanations, descriptions, illustrations and explorations of the associations between phenomena and their contexts. In a case study, one concentrates on a particular unit to understand a bigger class of units. Therefore, the case study involves decisively studying a particular case and does not involve unplanned selections. Case studies require a careful process of selecting cases through systematic research.

Apart from familiarizing oneself with academic discourse, the process of research includes innate processes when choosing and outlining cases.  At the start of the research project, the designation of a case depends on what is expected regarding information content. Sometimes, researchers may discover that what they determine from their research is different from the outcomes they had in mind; this may call for reframing the research. Some people see this as a weakness of case studies, but this is a strength in reality. A case study’s strong point is its depth, great detail, fullness, comprehensiveness in case variance, and its breadth when using statistical methods (Chen et al. 2009). Such depth is deliberated only to increase when using multidimensional exploration

A Case for Using Regenerative Drives in Elevator Modernization

Regenerative drives consist of a significant improvement in energy-efficient know-how in elevators, making it possible to recycle energy instead of wasting it as heat. They sustain the speed of elevators by seizing and changing the energy used from decelerating. In particular, traction elevators stabilise the passengers’ weight and the elevator car using a counterweight. This counterbalance is optimally sized, roughly to a car carrying 40%-50% of its capability.  Theoretically, if the counterweight is too weighty or too light, the elevator will overstrain both the motor and the braking system. In its place, medium weight is operative at making level the energy used while escalating or descending.

If the elevator carries a load that is more than half of its capability (cars going up to become lighter, while those going down are heavier) the elevator applies brakes to sustain the required speed. The braking is achieved by using the AC motor, as a generator, to transform mechanical energy into electrical energy, let off as heat using heat resistors. This energy is then seized by the regenerative drive and directed back to the house or the central grid. Yang et al. (2011), states that regenerative drives can bind and save energy in numerous ways for instance;

-During deceleration, an elevator applies brakes creating energy. This is wasted as heat in a conventional elevator system. A regenerative drive, on the other hand, saves that energy.

Each time an unoccupied or lightly laden elevator ascends, the lift applies brakes to sustain the right speed. Similar to the case of decelerating, that energy is wasted. The regenerative drives, however, save that energy. Additionally, as an unoccupied on lightly laden elevator ascends, the motor rotates, but it’s the elevators counterbalance that works most. This is not the case with a regenerative drive; this drive converts the mechanical energy from spinning into electrical energy.

-A weighty elevator that is descending needs to apply its brakes to sustain the desired speed. The energy that arises as a result of this is usually wasted in a conventional system. The regenerative drive saves such energy. Additionally, as a laden elevator descends, the motor rotates, but an enormous amount of work is done by gravity. This energy is saved and converted from mechanical to electrical by the regenerative drive.

-More energy is saved due to removing the necessity to cool the tools which are heated by the surplus heat emitted by orthodox motors

– As a result of being smaller, more efficient and compact than conventional motors, regenerative drives require a lesser energy amount.

When these small savings in energy are cumulated over a period, they contribute to substantial savings. Normally, energy use is lowered by 20% up to 40% when using a regenerative drive. The definitive amount of energy savings is determined by factors such as: how long the trips are, how frequently they are used and how old they are. Longer distances and higher numbers of trips would lead to more generation of energy.

Sun Chui Estate Overview

Sun Chui Estate is situated close to Che Kung Temple, Tai Wai Station and Lung Hang Estate. It comprises eight residential constructions finished between 1983 and 1985. The reason why Sun Chui was used as a target for the case study is bethathe elevators installed in the building had lasted for 32 years by the time its upgrading was being carried out. According to OTIS, an elevators life span is about 15 to 20 years after which it needs to be replaced.

Hin Keng Estate Overview

Hin Keng Estate is an assorted public and tenants purchase scheme estate located south of Tai Wai. It was so-called due to being close to Keng Hau and Hin Tin; the estate comprises right suburban structures finished between 1986 and 1989. A number of the flats were traded through TPS agreements to tenants in 2000.  Neighbouring these is another public estate called Hin Yiu that comprises only a single domestic structure. As a result of the long distance between Hin Keng Estate and MTR Tai HYPERLINK “https://en.wikipedia.org/wiki/Tai_Wai_Station”WaiHYPERLINK “https://en.wikipedia.org/wiki/Tai_Wai_Station” Station, the leading means of transport is by bus or minibuses that are available. However, plans are underway to construct a railway line that would link the Hin Keng Estate and provide an alternative means of transport. The reason why Hin Keng Estate was selected for use as a case study is that the building’s elevators had grown old and consumed a lot of energy, and therefore it needed to be upgraded.

OTIS Elevators Co

The Otis Elevator Company is established in the United States that constructs, improves and sells escalators, elevators, moving walkways, and similar equipment kinds. Being among the first companies in this venture, Otis is the biggest manufacturer of straight-up transportation systems such as moving walkways, escalators and elevators. This company came up with the idea of a “safety elevator”, developed in 1852 by Otis that applied exceptional methods to bolt the elevator in position in case the pulling ropes miscarried.

This company prides itself of installing elevators in well-known constructions including the original World Trade Center, Petronas Twin Towers, the Singing Tower at Bok Tower Gardens, Eiffel Tower, Empire State Building, CN Tower, The Twilight Zone Tower of Terror, the Demarest Building (first electric elevator), Burj Khalifa,  the Winchester Mystery House, the Hotel del Coronado, and the Skylon Tower. OTIS was selected for this case study because the company installed the old elevator in Sun Chui estate. As such, OTIS was better placed to carry out the upgrading of the same elevators.

ThyssenKrupp AG Elevators Overview

ThyssenKrupp AG refers to a multinational corporation domiciled in German, constructed in Essen and Duisburg’s cities. The corporation has 670 subsidiaries internationally. In 2015, this company was listed as the tenth-largest in the world by revenue. The corporation was formed through a merger between Thyssen AG and Krupp and currently, is headquartered at Essen. A big charitable organisation by the name Alfried Krupp von Bohlen-Halbach is the principal shareholder. The foundation’s name is in honour of its founder, who was also the proprietor of Krupp Company. ThyssenKrupp AG is the biggest steel producer globally, apart from steel production; it produces machines and industrial services for building ships and high-speed trains. Its subsidiary specialises in developing marine-related equipment for use by the German navies as well as foreign navies. The company has employed approximately 5,500 people and makes more than €1.6 billion as income in Spain, from elevators’ making. It also makes about €2.3 billion in Italy from the production of stainless steel. The sales in these two nations contribute to approximately 9% of the company’s revenue.

In 2007, the foundations for the organisation’s headquarters were laid. These were done in phases, with the first phase ending in 2010 and the final phase in June 2015. The design of the corporate campus was done by a Parisien company and another company from Cologne. The designs were so good to merit their selection for building in a competition for architectural design. ThyssenKrupp was chosen for the case study because the old elevators in Hin Keng Estate were initially retrofitted to the same company’s building. Hence it was justifiable for the company to carry out the upgrading.

Case Study 1

In a bid to show the main elements of energy-saving constituents of an elevator reconstruction in Sun Chui Estate, a case study was conducted by Otis Elevator Company. In each of the domestic constructions can be found double high-rise elevators mounted in 1985. Before modernization, the elevators depended on motor generators and direct current pulley motors governed by electromechanical relay controllers (Worth 2016). During the project, these old machines were replaced, with the DC motors changed for permanent-magnet hoist machinery of high efficiency. Regenerative drives together with relay logic regulators were supplanted with MCS 120 microprocessor regulators. This resulted in reduced electricity consumption and more reliable elevator and better quality of ride (Abdallah & El-Rayes 2015). This was in line with the estate owners’ desires for an elevator with better ride performance, enhanced dispatching, efficient use of energy, more dependable, and a better interior. They wanted a cheap overhaul of an old elevator to make it look new.

Case Study 2

The Lifts at the Hin Keng Estate were modernised using a power regeneration system whereby energy was reused whenever the elevator machine was running in the “generator mode”. By employing the lift power recovery drive, using recycled energy for a useful purpose instead of wasting it in the form of heat is an efficient strategy for overall energy preservation.

Lifts at the Hin Keng Estate were upgraded in such a way as to achieve flexible services for bottom floor zones as well as high floor zones (Andree et al. 2016). In 2013, the lifts were upgraded using energy-efficient regenerative drives.

Interviews

The data collection process consisted of questionnaires interviews with HKHA officials in the industry. The interviews aimed to establish the HKHA perspective after implementing the incentives to promote sustainable parts upgrading lifts. The questionnaires interviews were administered to 50 professionals in the HKHA. The interview was conducted over a period of 5 weeks. The questions were sent to the interviewees in advance, for the project managers to prepare themselves for the interview. This was done to give the managers a chance to read through the questions beforehand, which intended to prepare them and result in better thought-through answers. The interview study started with a pilot interview that was intended to provide an opportunity to observe how the interviewee interpreted the questions and provide us with more confidence before the actual interviews. After the pilot interview, the interview guide was evaluated and revised to make it better and more suitable for the remaining interviews.

The interviews varied between 45-70 minutes in length, and during the interviews, one of us took notes while the other acted as the interview leader. Furthermore, all interviews were recorded after permission from the interviewees, and notes were taken both during and after the interviews, as recommended by Andre et al. (2016). The interviews were carried out in the Chinese language because all participants had Chinese as their mother tongue, which leads to richer responses and a more limited risk for misinterpretations. In this study, all interviews were held for a short period. Rolstadås et al. (2014) argue that this has both benefits and consequences where the interviewers develop their knowledge throughout the process. If the interviews are done over an extended period, the recent interviews often tend to be performed with a higher knowledge base and therefore do not correlate well with earlier conducted interviews. It also complicates comparing the interviews in the academic process Rolstadås et al. (2014). However, Rolstadås et al. (2014) also brought up the benefits of gathering more qualitative data when the interviewer has time to analyse each interview before proceeding to the next. One other important aspect of the interviews’ performance is that the interviewers avoided using the words standardisation and freedom to prevent biased answers from the project managers, which was recommended by Hällgren (2012). Instead, questions concerning the interviewer’s perceived need to do things their way and how much company involvement they wanted were in focus. Furthermore, the answers are presented anonymously in this thesis, which is intended to increase the chance of receiving more clear answers from the interviewees. Although, this decision also has negative aspects since the respondents do not receive the same appreciation for their time and effort, Rolstadås et al. (2014).

There were 47 respondents with a response rate of 95%. The majority of respondents were building department officials (45%), architects (20%) and builders (35%). The interview, consisting of 15 questions, was designed to address the current building regulations related to refurbishments, especially for staircases and lifts/elevators in Hong Kong. 

ANALYSIS

Case Study 1 Findings

The Otis Elevator Co carried out an energy audit for the buildings.

Since the lift modernization initiative began after the refurbishment process was already taking place, the old elevators’ usage patterns could not be harnessed for this study. The estimates given below are for one run of an empty lift/elevator dispatched from the ground floor to the top floor and then back to the ground floor.

Critical Energy Usage

Lighting 0.71 kWh

Controller 1.40 kWh

Motor 0.15 kW per run

Otis Elevator Co suggested that the Direct Current (DC) motors be substituted with highly efficient permanent-magnet motors from the energy audit findings. The permanent-magnet hoist drives will optimise energy efficiency since high-efficient permanent magnets are employed instead of deriving electricity from an external source. As per the findings, OTIS also recommended using regenerative drives to capture the energy generated directly back into the estate (Worth 2016). The previous controllers had been recommended for replacement with Otis Elevator MCS microprocessor controllers to enhance ride dispatching, energy efficiency, lessen noise and offer accurate speed and leverage precision. Otis Co was also able to provide a gearless alternative for these lifts, which until 2000 was not available in lifts operating at velocities below 300 fpm. Otis Co is the only firm currently selling the 2:1 roping needed to handle the energy-saving gearless motors. The case study estimated that power consumption would result in a 45 per cent minimisation in electricity expenditure. The computation of the projected electricity savings was carried out using the Energy Cost Evaluation approach.

According to the case study, ELITE energy loggers were utilised throughout the controlled test runs to evaluate the previously used DC motors viz a new permanent-magnet motor. The elevators being evaluated were servicing the same building. Lifts were sent from the ground floor to the top floor and then back to the ground floor with the varying weight of objects, and no stops between floors (Worth 2016). Data were entered at the same sampling frequency for both lifts and values of the war and kVAr were taken for both the old motors and the new permanent-magnet devices. An evaluation of the data confirmed that no glitches or circumstances tempered with the findings or brought about questionable patterns.

The permanent-magnet system outdid the DC motors in all test studies from the case study, as shown in figure 3. The permanent-magnet drive consumed 44 per cent to 80 per cent less energy than the DC motor, depending on the weight of the load on the lift. The controller standby energy consumption was 60 per cent less with the new Otis microprocessor controlling system. In comparison, the installed LED lighting system contributed to an 80 per cent minimisation in energy consumption.

The kVAr values showed a different way in which modernised equipment can enhance the estate’s energy optimisation. The lower kVAr values for the upgraded lifts show that the new device uses reduce energy usage. This is because a lower kVAr reveals a higher electric power factor that could lower electricity expenditure when the local utility firms consider the electric power factor in residential billing estimates. The findings revealed that new permanent-magnet motor raises the power factor by 9 to 54 per cent based on the weight of motor loading, which could, in fact, result in an additional 15 per cent in energy cost savings.

Two elements in the Sun Chui Estate modernization project reduced the total energy cost. Typical 1980’s construction in this region utilised 200 line voltage. Hence a transformer was needed to standardise the line voltage with industry benchmarks (Worth 2016). The energy needed to run the transformer reduces the total energy minimisation by more than 15 per cent. Besides, if the area utility firm’s billing estimates used an adjusted rate because of the lower power element, Sun Chui Estate can realise an extra 15 per cent minimised energy costs. Either way, it is expected that this estate will notice a 60 to 70 per cent reduction in energy usage under the usual operating standards. In addition to minimising energy consumption, the cycle duration, or the time it comes from the bottom floor to the top floor and back to the ground floor has improved by 25 per cent with the newly installed permanent-magnet hoist drives.

This is as a result of two main elements. First, the old motor could not function at the specified 300 fpm because of performance problems. Secondly, the new, microprocessor controller allows for enhanced speed over the old mechanical relays and switches (Worth 2016). This enhancement in ride performance ride time and dependability leads to improved tenant satisfaction in the newly refurbished estate.

Several elements contributed to optimised ride performance after the upgrading process was complete. To begin with, vibration in the lift was significantly reduced. Vibration refers to the variation in acceleration degree when the amount is variably greater and smaller than the baseline level (Worth 2016). Within a moving lift, vibration is often caused by different surfaces and a device vibrating to convert them into a secondary source of sound. This vibration is caused by a lift moving via the shaft and changes in magnitude during each lift ride’s acceleration and deceleration factors. Other than this vibration, lift passengers are also somehow exposed to a high-frequency vibration caused by the main source vibration via the rotating drive system which is conveyed to the lift car by the lift ropes. The rotating devices conveying vibration are categorised as sheaves, bearings and motors, all of which have varying levels of frequencies which, at high alternating speeds, ought to be simultaneously balanced to mitigate unwanted vibration. The Otis Company application of gearless motor optimised ride performance to an unbeaten record of about 8-10 mg. A majority of the elevators using geared motors cannot limit vibration below 16 to 19 mg. The ride performance has also significantly improved since the modernised elevators can level themselves more accurately at every floor’s stopping point within the buildings. This is the main problem with ageing lifts, and with these modernisations, the levelling together with deceleration and acceleration issues were corrected.

The old machines were clumsy and took up an enormous amount of space, making it almost impossible to determine where the machine rooms were situated about the tenant houses. The upgraded lift minimises the lift room’s noise, thus optimising guest satisfaction in the adjacent rooms (Worth 2016). The needed amount of space in the elevator room itself was also reduced by more than 10 per cent, providing improved flexibility for the contractors that designed the refurbished estate. The old equipment also utilised carbon brushes that lead to the generation of dust in the equipment room. The modernization initiative got rid of the carbon dust generated by the carbon brushes.

The upgraded elevators have also been fitted with Otis Company signature Environment-friendly interiors. According to the Hong Kong Building Department requirements, the cab’s interior was made with materials that have low-VOC-emission and offer high air quality. A new UPS was also fixed to safely lift users to leave the elevator in case of a power shortage. The elevators’ upgrading implies that the elevators offer a more tranquil, dependable, and safe ride for the Sun Chui Estate tenants while significantly saving on the estate owner’s energy expenditure.

Case Study 2 Findings

The upgraded lifts on Hin Keng Estate had a capacity of 1,600 kg and an average speed of 6.5 ms-1, six ms-1, 2.5 ms-1, 4.5 ms-1, and 3.5,. The finding of the case study revealed that the amount of energy saved due to using regenerative drives depended on different factors, for instance, the lift capacity, acceleration and deceleration speed, weight of load and distance of travel.

The elevator regenerative system could attain an energy saving of about 26 per cent from the case study results. The high floor zone lifts could achieve more savings than the mid and bottom floor elevators under the same configurations. This shows that the magnitude of regenerative power recycled depends on the elevator operating velocity and travel distance.

According to ThyssenKrupp AG, regenerative elevators can save significant electrical energy under specific lift operating velocity and travel distance. For elevators operating at speed more than 2.5 ms-1 under lightweight load when ascending and heavy load when descending with the modernised lift, the energy-saving capacity is obvious. Lifts’ regenerative function can also significantly reduce the heat dissipation brought about by braking of lifts, hence saving total power usage of lifts. On the power quality element, the harmonic disruptions could also be reduced to preclude possible disturbance of the power system and cut down on the energy losses arising from harmonic currents.

Nevertheless, the payback time may be longer since the cost of energy-saving retrofit might be higher than the anticipated saving from the elevator regenerative drive. Also, an additional cost will be incurred should the existing lift drive could have been upgraded together with the integration of an accessory regenerative braking device.

However, the energy-saving of 28 per cent could be achieved via the elevator regenerative feature according to the case study on user lifts at the estate. According to the case study, the regenerative drive is beneficial for the new lift upgrades and retrofits on old lift replacements. Since energy saving is one of the major factors of most lift companies, it is ultimately believed that the elevator regenerative drive will become a benchmark requirement of lifts’ features, particularly for high-speed elevators.

Interview Results

From the interview, 82 per cent of the government officials, 78 per cent of the architects and 69 per cent of the builders agreed that lifts/elevators were essential means of vertical transport used daily in Hong Kong residential buildings. Twelve per cent of the government officers, 22 per cent of the designers and 31 per cent of the builders believed that staircases and not lifts were important components in high-rise buildings. Ninety per cent of the respondents reported that most old buildings had failed to comply with building regulations about lift modernization. The same respondents were fully aware of building regulations required to ensure repairs and proper maintenance of old lifts. As a matter of fact, 14 of the government officials referred to the Lifts/elevator Ordinance (Cap. 618), requiring all responsible persons to liaise with certified lift contractors to do regular maintenance lifts. Only three of the respondents who happened to have been government officials from the building department said they were not fully conversant with the entire regulations on lifts/elevators. Forty-one out of the 47 respondents believed old residential buildings need to be retrofitted with energy-efficient lifts/elevators. The remaining six respondents value safety more than sustainability in lifts. Aware that the lift upgrading process is costly, the building department respondents reported that the Hong Kong government had established a scheme to motivate residential building owners to refurbish their premises. The respondents emphasise that building owners can get technical support and financial help in conducting thorough building maintenance operations where the lift/elevator modernising works can be factored in.

On the other hand, 30 respondents believed that there had been challenges in designing energy lift codes and regulations because Hong Kong has historically depended on the central government for managing power consumption.

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Discussion

According to Yau, Ho, & Chau, (2008), it is proven that a single modern elevator based in Hong Kong City can draw up to 100 kW and can utilize regeneration to compensate for this sign. Several elements combine to give an important prospect to cut down on elevator weights 50 per cent or more. The latest elevator regenerative systems can go a long way in improving performance, saving power usage, and providing an enhanced user experience. The advances in replacing old elevator parts with new ones have greatly reduced the costs associated with new elevator installation (Yik & Lai, 2008). Advanced regenerative drives systems, generally laced with permanent hoist motors, have facilitated saving energy savings. This explains the results found with the upgraded elevators in Sun Chui and Hen Seng estates. Other studies have reported that old elevators can be incorporated with column regeneration instead of heat dissipation (Ho, 2007).

In contrast with elevators using DC motors, modern traction lifts have been discovered to control velocity with regenerationutilizing the motor as a machine to supply power back to the grid system. In this case, the gravitational forces based on the downward lifts are weighty instead of counterweight on the downward weights when they are heavier than the lifts generates when the motor brakes of regenerative drives slowdowns it gives back its power. However, this power degenerates as a waste in the form of heat in a conventional lift system. Nonetheless, current regenerative systems can infuse this energy back to the building (Chan & Kumaraswamy, 2001).

Hydraulic and grip lifts require efficient machine rooms for motor equipment and control due to the older controls, power trains, and safety systems’ size and intricacy. In penthouses, traction elevator machine rooms are placed slightly above the lift shafts, and this has proved to be inefficient since they often require additional cooling. Advances in motor, control and rope technology have led to new installations with machine-roomless (MRL) features that can house the lift hoistway’s traction motor (Jaillon & Poon, 2008).

The previous DC motors in elevators were built using induction materials. However, more recent traction lifts use permanent hoist motors, which have been thought to be extra compact and come with higher energy effectiveness and enhanced speed control, using the regenerated drives. These utilise regenerative inverters do not need the old DC motors’ high-powered resistor banks (Hong, Polytechnic, Kong, Chan, & Tam, 2000).

Lo, Fung, & Tung, (2006) argue that upgrading old elevators with regenerative drives is, in fact, cost-prohibitive, as a result of an almost conventional low-duty cycle of modernized elevators. The same author maintains that the perfect opportunities to save energy usage lie in-cab enhancement, maintaining correct valve adjustment, and successive standby modes for distinctive applications of improved lifts (Nguyen & Gaudet, 2000). Even though some elevator improvements may appear self-effacing, there is still a lot of potential for reducing the overall energy usage beyond the levels reported by the Hen Seng and Sun Chui estates case study. Generally speaking, upgrading old elevators, especially by replacing old drives, should be highly encouraged, as evidenced by the case study results.

Looking at the Hang Seng and Sun Chui elevator upgrading from a project management point of view, it is clear that a project manager should come up with a proper performance measurement system for the upgraded elevator’s energy input. Project Performance Measurement has been perceived as an important element of project controls for offering the criteria for managing and controlling construction projects by bringing to bear their inefficiencies (Nobile et al., 2014). The use of the performance measurement principle in construction projects can be applied in elevator upgrading projects. According to Khandelwal, Talukdar, & Jain, (2011), a performance measurement system, whether construction or any other sector, begins by recognizing a balanced set of pointers whereby performance can be measured. Numerous studies have been conducted on the adequate performance set for measuring the fiscal and nonmonetary essentials of construction procedures representing their factual presentation.

It is currently estimated that about 5 million lifts have been installed in Hong Kong residential high-rise buildings. Considering the demographic trends and a growing need for convenience and comfort, Grbovic, Delarue, Le Moigne, & Bartholomeus (2011) argue that the number of HK elevators will be rising.

When it comes to having sustainable buildings, most people think of energy-consuming elements such as boilers and lights. However, according to Ding, Yang, Weng, Fu, & Rao (2015), another important energy guzzler happens to be the source of unutilized energy savings in several high-rise residential buildings; the elevators. The same author maintains that a “regenerative elevator system” can harness some of the energy actually wasted in daily operations.

Locker Wayne, the technical support team leader for Transel Elevators, reports that there are three important ways that an elevator wastes energy and that a regenerative drive can save it. Firstly, whenever an elevator decelerates, energy is made. In a conventional elevator system, this energy is released as heat energy via a device referred to as a heat resister. Secondly, with a regenerative drive, the released energy is harnessed and fed to the elevator’s power grid.

Besides, whenever an empty elevator ascends, the motor run show ever, the elevator’s counterweight executes most of the work (Nobile et al., 2014).

Besides, a regenerative system can allow the motor to basically act as a generator, creating energy that also gets fed to the power grid. Furthermore, when a heavily loaded elevator descends, the motor run show ever, the force of gravity does most of the work.

Thus, a regenerative system can again capture the power and feed it to the grid.

Khandelwal et al. (2011) argue that a regenerative drive enables a building to utilize less power. Nevertheless, it is quite hard to approximate how much energy largely depends on the height of the building, the retreat in which the elevator is being used and the age of the elevator. But generally, a regenerative drive can allow a high-rise building to use between 15 and 45 per cent fewer energy elevators. Whereas elevators in a residential premise lead to only about six per cent of total energy consumption, the energy savings can also arise from the fact that if the energy isn’t released as heat, the elevator rooms do not have to be cooled as much as with a traditional elevator system (Bukowski, 2003).

According to Williams Ricky, a project manager for the UK’s Computerized Elevator Control Corporation (CECC), the energy savings in upgraded elevator scan vary; he approximate with regenerative systems, a building could expend (Hakala, Siikonen, Tyni, & Ylinen, 2001) 20 to 45 per cent less energy to run elevators. Ricky referred to an elevator regenerative project executed in a New York City residential building where the money required to operate the 30-story building’s eight elevators was cut down by $ 6,000 one year after upgrading old elevators regenerative drives were completed.

Kuligowski (2003) maintain that the amount of cost of upgrading old elevators with regenerative drives can vary significantly, depending on many factors. For instance, it depends on the type of drive used for the upgrading, the elevators’ existing condition, the height of the premise, and the regenerative systems’ demand. The regenerative parts alone have been reported to cost between $8,000 and $10,000 per elevator (Karlis, 2014).

Most elevator companies help residential property owners who are thinking of upgrading old lifts with regen drives in various parts of Hong Kong. One cannot know for a fact how many upgraded elevators actually used. As a matter of fact, project managers are integrating energy data-loggers into elevators to monitor elevator utilization to help the construction industry decide if regenerative drives could be worth the cost and the kind of technology they can utilize.

In one rental residential building, Karlis (2014) reported that a simulation system confirmed that regenerative drives could not save enough energy to warrant them economically viable. However, the data that tracked real energy usage indicated that the elevators used five times more energy than the simulation model reported. Thus project managers have to look at the actual numbers to assess the cost-effectiveness of regenerative drives.

One of the residential property owners in Hong Kong considering upgrading old elevator with regenerative drives reported that his building was looking into a variety of modernization options, from regenerative systems to changing the old DC motor systems of the lifts so that they can run on AC that, instead of the DC most of the old elevators run on. Nevertheless, to implement the project, a project manager must use a project performance measurement system to determine how much energy the elevators actually consume (Rufer & Barrade, 2002). For instance, if a building decides to utilize regen drives as part of its lift modernization, they would have to pay for them out of a mix of measures, probably combining finance from reserves, funding and evaluations.

Other elevator and energy scholars argue that regenerative drives can replace old DC motors in old elevators without necessarily upgrading the whole system. However, according to Tamura, (2009), the Hong Kong city elevator codes and regulations are expected to change in 2020 to comply with more rigorous safety requirements. As such, many property owners would have to modernize their elevators nevertheless.

Built environment researchers and practitioners are addressing the current sustainability and energy challenges facing the industry. The shift in building energy and sustainability expectations has led project teams to develop new practices and processes. Owners, project managers, designers, and contractors now actively seek opportunities to improve existing buildings’ energy performance through retrofitting. Given that integrated system upgrades result in more significant energy reduction rates than traditional approaches, this study adopted a case-study approach to understanding the integrated system design process and its effects on energy-efficiency performance measures in retrofit projects compared to traditional retrofit processes (Nguyen & Gaudet, 2000). Within this scope, three retrofit projects with different processes and rates of energy consumption reduction were purposefully selected to meet certain project delivery and system design characteristics. This paper focuses on the effects of these characteristics on the collaborative decision-making process and integrated system design. Its main contribution lies in analysing critical decisions related to process and performance modelling practices in the delivery of retrofit projects. As a consequence, it was found that while collaborative energy benchmarking and the performance goal setting provided a transparent decision-making environment, the review of existing conditions before design and the use of historical operational performance data made the iterative energy modelling of an integrated building system design realistic (Bukowski, 2007).

In the current construction industry setting, efficient performance measurement methods have influenced many construction firms, public, private and government sectors, and other project stakeholders. In this scenario, performance measurement is displayed as the standard way of accumulating and reporting data regarding the inputs, competence and effectiveness of construction assignments. Construction projects use performance management to evaluate their performance in monetary and non-monetary stipulations and to differentiate their performance with similar projects to improve their efficiency and effectiveness in their projects. Likewise, according to Rufer & Barrade (2002), measurements are required to track, predict, and eventually manage those significant variables to the project for a construction project to be successful. Various researchers and practitioners agree on this (Mahgoub & Abbara, 2012).

Barney, (2003) argues that those performance measurements apply not only to product or service quality but should also be extended to other sectors such as quality management, client satisfaction, demands and requests which integrates the major stakeholders which are the shareholder, customer and employees. The performance measurement can be classified into three main categories. The first category refers to the numerical indicators; the second category is qualitative matters and lastly on what and whose performances are to be measured.  This is in agreement with Oldfield, Trabucco, & Wood, (2009) who denotes that the ‘hard’ and ‘soft’ sides of project measurement decisive factors are used in gauging project success, with time and cost being ‘hard’ and satisfaction being ‘soft’. Research conducted by Barney, (2003) and Al-Kodmany, (2011) views performance measurement in terms of concrete and non-concrete aspects whereby costs and time are concrete, and customer satisfaction and performance of the project manager are non-concrete. The project results have to be compared with the initially planned effort and reference value to ascertain the standard (Nguyen & Gaudet, 2000).

This paper synthesizes various systems of measuring project performance in the United Kingdom, the USA, France, India, Hong Kong, Saudi Arabia and Malaysia. The performance variables thrown up from this synthesis are then analysed to see if they reveal meaning patterns. Two models developed for measuring construction project performance are integrated performance indexes (Pillai et al., 2002). Key performance indicator (Construction Industry Task Force, 1998) Integrated Performance Index was developed by Pillai et al., (2002) for performance measurement of R&D projects, based on their real-life experiences of working on the management system for the Integrated Guided Missile Development Programme of India. The model identified three project phases and dealt with performance elements such as performance indicators or key factors associated with each phase; the stakeholders; and the performance measurements. The three project phases identified are the project selection phase, the project execution phase and the implementation phase To measure the performance of an R&D project, Pillai et al., (2001) listed eight prominent factors that cut across the three project phases as follows: benefit, risk, project preference, project status, decision effectiveness, production preparedness, cost-effectiveness and customer commitment. By integrating these key factors using mathematical formulae, an integrated performance index (IPI) is computed based on their functional relationships. The usefulness of the integrated performance index is that it can be applied at all the phases of the project life cycle to rank the project for selection, compare project performance under the execution phase, and act as an input for future projects management. One problem of the model is the lack of clarity in how the mathematical formulae are used to integrate the identified key factors into an integrated performance index. Given this shortcoming, this model is not well received by practitioners. Key Performance Indicators (KPIs) in the UK construction industry respond to Egan’s report (Construction Industry Task Force, 1998) to measure project performances, based on 10 identified parameters. These consist of seven project performance indicators; construction cost, construction time, cost predictability (design and construction), time predictability (design and construction), defects, client satisfaction with the product and client satisfaction with the service; and three company performance indicators namely; safety, profitability and productivity. The model begins by establishing the fundamental ‘key drivers for change’, which comprise committed leadership, focus on customer needs, product team integration, a quality-driven agenda and commitment to people. The key drivers’ quality-driven agenda means that the total package needs to deliver zero defects, be right the first time, deliver on time, budget, and exceed customer expectations.

As part of the KPIs, definitions are provided with the industry performance graphs and a radar chart. The graphs allow analysis to be made by companies of their own results, by assessing these and comparing them with the radar chart that acts as a simple performance score-card. This model’s strength is that the overall concepts are easily understood and easily implemented by clients, designers, consultants, contractors, sub-contractors, and suppliers. One problem with the model is that the KPIs are not compartmentalized along with project phases.

Three models for measuring construction project quality performance model, based on critical variables developed by Chan (2001); blueprint by the Quality Performance Measurement Task Force (QPMTF) of the Construction Industry Institute (CII) for measuring quality performance on engineer-procure construction (EPC) projects in the United States (Glagola et al., 1992; Stevens, 1996); and Quality Assessment System in Construction (CLASSIC) model developed by the Construction Industry Development Board of Malaysia to assess the contractor’s performance in terms of quality of the finished product (CIDB Malaysia, 2001b). Chan (2001) developed a project quality performance model based on some empirical study of project critical variables involving Hong Kong construction projects. Those variables are groups under the client’s headings, project, project environment, project team leader, project management action and project procedure. These variables are regarded as independent variables where these variables’ impact and interaction will determine the dependent variable (i.e. quality performance). The client variables are identified from the nature of the organization, public or private sectors, clarity of project mission, competency in terms of ability to brief, make decisions, and define roles.

The importance of project characteristics and external environmental factors contributing to the project process and providing remarkable indicators in assessing quality performance are highlighted. It is expected that the quality of a project depends to a large extent on the skills and experience of project team leaders; managerial system (in terms of decision making, choosing the correct strategy, setting-up specific objectives, selecting people, delegating responsibilities and evaluating results); and the procedures adopted during the construction process (in terms of the concept of procurement form and method of tendering). A causal relationship between the factors affecting quality performance was established, which shows that an increase in client satisfaction with quality is achievable through better project management actions, team leader’s effectiveness, viability, and feasibility of the project environment’s procedures and stability. One of this model’s weaknesses is that the variables are not grouped based on project phases and fail to identify the project stakeholders’ responsibilities, needs, and expectations in each project phase.

The blueprint outlines a process that first identifies project variables that are important in improving quality; secondly, it illustrates why and when these variables should be measured; thirdly, it furnishes examples of how to measure these variables, and finally suggests how the measurement results can be used in making project decisions. Those measurements are implemented according to the project phase.

CONCLUSION

The management of tall residential buildings in Hong Kong has attracted a lot of attention due to the disproportionate increase in retrofits’ energy consumption. One of the most energy-consuming retrofits in high-rise residential buildings are the elevators. Most of the residential property owners in Hong Kong are forced to replace old elevators with new and energy-efficient ones. However, the cost of replacing inefficient elevators with new ones can be extremely high. Thus this dissertation has validated a strategy of saving on old elevators’ energy by replacing DC motor drives in old elevators with regenerative drives that are energy efficient.

In particular, this research study has applied project management system techniques to the modernization of old elevators in residential buildings in Hong Kong while ensuring that the lifts’ upgrading process meets Hong Kong Building Department requirements. It has been found out that replacing DC motors with regenerative systems in elevators can go a long way in saving on energy consumption. This project has accomplished its aims by evaluating two case studies on lift modernization projects in Hong Kong residential high-rise buildings, focusing on DC motor upgrading with regenerative drives.

As a matter of fact, it can be confirmed from the case studies that regenerative drives are more efficient than DC motors in terms of saving energy. Also, from the interview outcome with various construction sector stakeholders, it can be concluded that the Hong Kong construction sector recommends utilising a sustainable upgraded elevator in the modernisation of lifts. Thus, the use of energy-saving parts in elevators’ renovation can help cut down on the overall energy consumption in high-rise family buildings. This will be advantageous to both the landlords and the tenants in terms of cost-saving.

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