A cost-benefit analysis of green buildings with respect to construction waste
minimization using big data in Hong Kong
Xi Chen, Weisheng Lu, Fan Xue, Jinying Xu
This is the post-print version of the paper:
Chen, X., Lu, W., Xue, F., & Xu, J. (2018). A cost-benefit analysis of green
buildings with respect to construction waste minimization using big data in Hong
Kong. Journal of Green Building, 13(4), 61-76. Doi: 10.3992/1943-4618.13.4.61
The final version is available here: https://doi.org/10.3992/1943-4618.13.4.61

Abstract
It is readily accepted that the extra construction costs involved in the construction of green buildings
will result in benefits including lower operation costs, higher sale/rental prices, and better
sustainability performance. However, there has been little recognition of construction waste
minimization (CWM) as one of the important benefits of sustainability performance as designated in
green building. This paper aims to provide a better understanding of cost benefit of green buildings
with respect to CWM by using big data in the context of Hong Kong. The study is innovative in that
it conducts a cost-benefit analysis specifically on CWM of green buildings by mining large-volume
datasets. A surprise finding is that Hong Kong’s green building rating system (GBRS), i.e. the BEAM
Plus, has a negligible effect on CWM, while it generally increases construction costs by
approximately 24%. Hence, the increased construction cost of green buildings cannot be offset by
CWM if corresponding items in the BEAM Plus are not properly incentivized. This paper
demonstrates the necessity of emphasizing CWM-related items in GBRSs and of taking appropriate
measures to deal with them. It also provides better decision-support information on the increased
construction costs and the attainable benefits of green building that developers may wish to take into
account when initiating a green building project.
Keywords: Green building, cost-benefit analysis, construction waste minimization, big data, Hong
Kong
1. Introduction
Green building is becoming fashionable in the built environment development worldwide. It is
promoted to address major contemporary challenges such as natural resource depletion, pollution,
greenhouse gas emissions, and human-induced global warming. Here, building is cleverly used as a
polysemy; it refers to both a noun to represent a physical building structure and a gerund to describe
1

the building activity. It is generally recognized that extra construction costs would be spent on green
building compared with regular buildings, as ‘going green’ often needs more expensive materials,
facilities, technologies, and acquiring new expertise (McAllister, 2012; Lu and Yuan, 2013). For
sustaining the economic legitimacy of green building, the extra construction costs must be offset by
higher economic and/or sustainability benefits on a later stage. Numerous cost-benefit analyses
(CBAs) have been conducted to ascertain whether the propagated economic/sustainability benefits
have truly been attained in buildings awarded a green building certificate. Some studies have found
that the results are largely positive (e.g. Newsham et al., 2009; Menassa et al., 2011; Gou et al., 2013),
while others have reported unfavourable findings (e.g. Scofield, 2009).
Construction waste minimization (CWM) is one of the important benefits that are stipulated in most
green building rating systems (GBRSs). Construction waste, also called construction and demolition
(C&D) waste, is responsible for a large proportion of total solid waste (HKEPD, 2015a). Owing to
its non-combustive nature, C&D waste is normally landfilled, which often leads to extensive amounts
of air, water, and soil pollution due to production of CO2, methane, and leachate. Landfilling will
also deplete valuable landfills quickly. For example, Hong Kong has suffered from a rate of about
3,500 m3 per day of landfill space depletion (Poon et al., 2001). Recent data shows that Hong Kong
landfilled 4,200 tonne of construction waste per day in 2015 (HKEPD, 2015a), and is faced with all
existing landfills being filled by 2020 (HKEPD, 2005; GovHK, 2017). In fact, only a very small
proportion of construction waste, which is non-inert, needs to end in landfills (HKEPD, 2015a).
Construction waste reuse and recycling have become a worldwide task, but in previous studies little
attention has been paid to achieving CWM along with the promotion of GBRSs.
To address the problems identified above, this paper examines whether the extra construction costs
driven by GBRSs has been well spent in terms of CWM performance improvement by conducting a
CBA. As a precondition of the CBA, the paper first examines the existence of extra construction
costs involved in pursuing green buildings. A CBA of GBRSs, specifically with respect to CWM, is
then conducted by taking advantage of a large-volume dataset from Hong Kong’s green building
movement, construction waste management practices, and building statistics. The remainder of the
paper is organised as follows: section 2 provides a literature review of the extra construction costs
for green buildings and cost benefits, with a focus on CWM; sections 3 and 4 are the methodology
and data descriptions respectively; section 5 presents an analysis of the cost benefit of GBRSs with
respect to CWM using empirical data; and sections 6 and 7 discuss the results and draw conclusions
respectively.
2

2. Literature review
This section conducts literature review relating to gain an understanding of the extra construction
costs of green buildings. Then, the status quo of CWM has been presented for identifying the
importance of effectively implementing CWM through promoting GBRSs. The benefits that can
offset the extra construction costs of green buildings are reviewed from a CBA perspective with a
view to establishing the necessity of studying CWM benefits instead of focusing solely on cost
rewards.
2.1 Extra construction cost of green building
The development of green buildings goes beyond traditional codes of practice by demanding a higher
and voluntary standard for achieving sustainability performance. The widely propagated benefits of
green buildings include lower operation costs (Gowri, 2004; Olanipekun et al., 2018), higher
rental/sale prices (Kats, 2003), the enrichment of biodiversity and protection of the ecosystem
(Bianchini and Hewage, 2012), reduction of greenhouse gas emissions (Shuai et al., 2018), energy
saving (Cheng et al., 2011) and improved health conditions for occupants and greater social
productivity (Zhang and Altan, 2011). GBRSs provide voluntary frameworks containing criteria that
a green building should meet.
Since the emergence of green buildings, a growing body of literature has been focusing on the costs
involved in their design and construction. Many building professionals argue that green buildings
can result in higher construction costs, a contention that researchers have largely confirmed. For
example, studies have found that an extra construction cost of 3-15% is required for developing a
green building, depending on the region and the applied GBRS (Bartlett and Howard, 2000; Miller
et al., 2008; Langdon, 2007). Quantity surveyors in the UK have claimed that more energy efficient
and environmentally friendly building cost between 5% and 15% more to build from the outset,
although this number has been questioned (Bartlett and Howard, 2000). Miller et al. (2008) estimated
the extra construction cost for LEED at 7-11% for Platinum, 3-7% for Gold, and 1-4% for Silver,
depending on the region; and Langdon (2007) estimated the extra construction costs for achieving
Green Star to be in the order of 3-5% for a 5-star solution, and more than 5% for a 6 star non iconic
design solution.
Different economies will have disparities in the extra costs for green building. As this study is
contextualized in Hong Kong, the extra cost is calculated to contribute to the knowledge of the price
3

for “going green” in that jurisdiction, where the Building Environmental Assessment Method
(BEAM) (currently BEAM Plus) is the dominant GBRS. This study takes advantage of second-hand,
objective data to calculate the extra construction cost of BEAM-driven buildings, to on one hand
investigate the extra construction cost for green building in Hong Kong, while on the other hand
provide credible information for the reference of stakeholders, such as developers, researchers, and
consultants.
2.2 CWM as an important benefit of green building
Many studies have assessed the life-cycle cost of green buildings to determine whether the extra
construction costs can be offset by economic or sustainability benefits, such as energy saving, less
material waste, and water saving in the later stages of a building's life cycle. CWM is one of the
frequently-cited benefits. Construction waste, also called construction and demolition (C&D) waste,
is defined as the surplus and damaged products and materials that arise from construction, renovation,
and demolition activities (Roche and Hegarty, 2006). Construction waste often constitutes a
significant portion of the total solid waste, which primarily consists of municipal solid waste (MSW),
construction waste, and special waste (Lu et al., 2016c; HKEPD, 2015a). In the U.S., the amount of
construction and demolition (C&D) waste generated in 2014 before recycling has been estimated as
534 million tons, which is twice the amount of MSW generated in that year (USEPA, 2016). The
European Commission (2013) reported that construction waste is responsible for 25-30% of all waste
generated in the European Union. According to Monitoring of Solid Waste in Hong Kong: The Waste
Statistics for the ten years from 2005 to 2015, the percentage of construction waste ending up in
Hong Kong was about 23-28% of total solid waste (HKEPD, 2015b). In Japan, construction waste
contributes 20% of the total solid waste generated by all industries (MoE, 2014). Construction waste
is mainly in two mainstreams: non-inert waste and inert materials (Lu et al., 2016a). At present, most
non-inert construction waste ends up in landfills rather than being incinerated or recycled. However,
landfilling waste has caused considerable pollution to air (Chang et al., 1996), water (Mor et al.,
2006), and soil (Garcıa-Gil et al., 2000). Landfills also take up valuable areas of compact cities such
as Hong Kong and Singapore (Lu and Tam, 2013; Lu et al., 2016b; Chen and Lu, 2017).
As a response to the negative environmental impacts of construction waste, CWM is one of the most
important environmental issues stipulated in various GBRSs. On average, CWM-related initiatives
account for roughly 10% of the total points awarded in the prevailing GBRSs, e.g. LEED (10%),
BREEAM (8.16%), Green Globes (11.5%) and Green Building Index (8%) (Wu et al., 2016).
However, there is no reliable empirical evidence concerning the effect of such schemes on CWM.
4

Allowing CWM efforts to account for 10% of all points awarded in a GBRS without concrete
evidence of their effect not only constitutes a significant knowledge void but also poses problems
for green building development. The effects of green building certification on CWM are a common
query in various stakeholder engagement exercises, but the answer is either not forthcoming or it is
ambiguous. Without knowing their real effects, CWM-related points may be surrendered to other
green initiatives, such as energy efficiency or water conservation, with almost certain knock-on
effects to investors, owners, designers, consultants, and contractors.
2.3 Lack of CBAs of GBRSs targeting CWM
Although CWM is one of the multiple cost benefits of green buildings, it has never been examined
using empirical data. It is argued that green buildings can achieve legitimacy if the extra construction
costs involved can be offset by benefits at a later stage, e.g. throughout the building lifecycle (Zuo
and Zhao, 2013). The benefits of green buildings can be classified as two types: economic benefits
and sustainability benefits. The GBRS-driven economic and sustainability benefits, such as energy
saving, cost saving, and improved life quality (Cheng et al., 2011; Zhang and Altan, 2011) are well
understood from previous studies, but CWM as an important cost benefit remains somewhat of a
mystery. By using large datasets from the green building movement and CWM practices in Hong
Kong, this study therefore examines whether practitioners have effectively accomplished CWM in
accordance with GBRSs’ original intention.
3. Methodology
This section presents the methodology of the study based on the research aim and objectives.
Hypotheses are proposed for testing with quantitative analysis, and a GBRS is selected and described
as the basis for analyzing the relationships between green building, construction costs, and CWM.
Finally, the methods used for testing the hypotheses are presented.
3.1 Hypotheses
This research defines a GBRS-driven project as a project that has achieved a GBRS certification,
been unclassified, or just registered for green building accreditation at the time of data collection. A
non-GBRS-driven building is referred to as a regular building in this study. Considering that all the
recognized GBRSs include the scope of CWM, it is hypothesized that:
H: GBRS-driven buildings cost more but perform better in CWM than regular buildings.

5

There are actually two interconnected hypotheses: one posits that GBRS-driven buildings cost more
than regular buildings (H1) and the other posits that GBRS-driven buildings generate less
construction waste than regular buildings (H2). It is emphasized here that construction costs often
include the land cost and construction cost. However, this study does not consider the former, as land
cost barely matters in relation to green features, and could go extremely high in some land- scarce
cities to distort the building cost formula. For construction cost, this study investigates the main
stages of foundation and building, otherwise known as substructure and superstructure.
3.2 GBRS in focus: BEAM Plus
Hong Kong’s BEAM Plus has the common scopes of energy saving, water conservation, site
selection, building materials, and indoor environmental quality as other GBRSs (Cole, 2003; Wu and
Low, 2010; Wu et al., 2016; Li and Yang, 2014). Due to its well-recognized effectiveness in the
green building movement and full recording of the projects involved, this study used the BEAM Plus
as the representative GBRS to test the hypotheses. The BEAM Plus is the most recent version of
Hong Kong BEAM that was first launched in 1996. As a result of having evolved in response to the
needs of the local built environment over two decades, the BEAM Plus was established in November
2012. It has a similar scope to the UK BREEAM (Prior, 1993) and groups the green features of a
building into six aspects: Site, Energy Use, Indoor Environmental Quality, Materials, Water Use,
and Innovations and Additions. CWM-related items are mainly in the Materials aspect.
Buildings assessed by BEAM Plus may be issued an Unclassified, Bronze, Silver, Gold, or Platinum
label, or simply recorded as “registered” for BEAM Plus certification. All BEAM-driven buildings
are taken into account as the sample in this study. Certain buildings grouped as regular might have
also achieved higher performance of CWM performance, or cost higher than some BEAM-driven
buildings, owing to other factors. Examples of better CWM performance are that a regular building
was constructed according to other GBRSs, or a regular building developer skilfully managed the
materials. Although such projects exist, they are in a minority among regular projects. As no two
buildings are totally the same, this study avoids a case versus case comparison and instead conducts
a group versus group comparison. Accordingly, this study compares the CWM performance and cost
between a group of BEAM-driven buildings and a group of regular buildings. As a result of using a
considerable number of buildings instead of just a few cases, the control variables that may affect
construction costs and CWM performance are considered ‘controlled’.
3.3 Testing H1
6

For the purposes of comparing the construction cost of regular projects with that of BEAM-driven
projects, unit construction cost (UCC) is used. The UCC is calculated on the cost spent on each unit
of GFA built (e.g. ft2 or m2). The UCC of a building i is defined as: UCCi=Costi/GFAi, where i is the
building project number, Costi is the construction contract sum of building i, and GFAi is the gross
floor area of the building i. The contract sum accounts for only the cost in the construction phase.
The hypothesis is tested by comparing the UCCs between the group of BEAM-driven buildings and
the group of regular buildings.
3.4 Testing H2
Waste generation rate (WGR) has been widely used as a proxy of waste minimization performance.
A WGR of a building can be calculated by dividing the waste quantity (volume by m3 or weight by
tonnes) by the amount of construction materials, gross floor area (GFA) (Formoso et al., 2002), or
construction contract sum (Lu et al., 2016a); it reflects the wastage rate of producing every unit of
construction work. GFA is accepted as being the best description of the physical profile of a green
building and as a denominator to understand WGR (e.g. worth of construction work). Following this
argument, the WGR of building i is defined as: WGRi=WGi/GFAi where i is the building project
number, WGi is the total waste generation of building i, and GFAi is the gross floor area of building
i. This hypothesis is tested through comparing the WGRs between the group of BEAM-driven
buildings and the group of regular buildings.
4. Data Description
4.1 Data sources
A Construction Waste Disposal Charging Scheme has been enacted in Hong Kong since 2006. It
mandates main contractors to pay for the disposal of construction waste in government facilities,
such as landfills or public fills. Contractors are mandated to dispose of their waste at the facilities, if
not otherwise properly reused or recycled. The HKEPD records every truck of construction waste
received at these facilities. This leads to around 3,300 incoming records every day. The waste is
generated from various projects, with their profiles such as site address, client, and project type being
recorded. This study uses all the waste disposal data from 1 January 2011 to 31 Dec 2016 in Hong
Kong, totally 7,591,742 records generated from all the 26,566 C&D works (see Figure 1). All the
data were well structured in various databases, based on which the dependent variable WGRi was
calculated. This study has also sourced the data of all the 924 buildings (as of 20 March 2017) that
have been certified or registered for certification by BEAM Plus. The information of the 924
buildings, including project names, site addresses, level of green building label, and their waste
7

generation records, was extracted and forms the big data set as shown in Figure 1. In addition, for
linking the GFA of the studied buildings, the information of 9,313 buildings has been extracted from
the Monthly Digest of Hong Kong Buildings Department from 2005 to 2016 for bridging the contract
sum and GFA of the same buildings according to their site addresses. The 924 BEAM-driven projects
have been removed from the 9,313 buildings to generate a group of regular projects with the largest
accuracy. Section 5 elaborates on the links between these databases. In order to simplify the names
of the databases, Table 1 shows abbreviated names and recorded numbers.

Figure 1 Structure of the big data and links between databases
Table 1 Descriptions of big data
Abbreviation

Database

Number

CDP

Construction and demolition projects

26,556

BDP

Buildings that have applied BEAM Plus

924

BDMD

Buildings Department Monthly Digest

9,313

WDR

Waste disposal records

7,591,742

8

4.2 Sample selection
The data finally employed for analysis accounts for a small part of the big datasets. Data mining is
used for the purpose of extracting useful information from a large volume of data. For calculating
the UCC, a link between the contract sum and GFA needs to be established. For calculating the WGR,
a link between the waste generation amount and GFA needs to be established. The contract sum is
in CDP, GFA is in BDMD, waste generation amount is in WDR (referring to Table 1). To link the
waste amount with GFA, the only bridge is the construction site address. Therefore, the construction
site addresses can be used as a bridge linking BDMD, CDP, and BDP to select the samples for
BEAM-driven projects and regular projects according to the following criteria:
a. The same address should exist in BDP, BDMD and CDP, for extracting samples of BEAMdriven projects.
b. The same address should exist in both BDMD and CDP, but not in BDP, for extracting
samples of regular projects.
There is only construction site address in common between the above three databases. Their
longitude and latitude are geocoded by engaging the cooperation of the Google Geocoding Service.
The links are then established by automatic matching, manual checking the errors, and matching the
address without an exact longitude and latitude. Although the matching is not ideal, a considerable
sample size is available for data analysis. In addition, although there is no address in WDR there is
an account number that can be used to represent a site address, which can link WDR and CDP to
calculate the waste generation period and the amount for each project. This study regulates that the
period for selected samples should fall in the range from 1 February 2011 to 30 November 2016.
This is to largely increase the possibility that all the projects selected were finished during the period
of 2011 to 2016. If a project still generates waste in either one of those two months, it probably had
started before 2011 or had not yet ended in 2016. For guarantee the data completeness of selected
samples, this study regulates the projects should have no waste generation in either January 2011,
the beginning time of the collected waste records, or December 2016, the end time. Since during the
linking process there were a large volume of projects that failed to establish links, the samples for
carrying out the comparison are comparatively smaller than the original datasets; they are however
still very considerable. After linking and filtering according to a 90% confidence level, the profile of
the available construction costs for comparison is displayed in Table 2, and that of the available
WGR is in Table 3.
Table 2 Sample sizes for UCC comparisons between regular and BEAM-driven construction works
Construction stage
Foundation
Building

Regular
180
197

BEAM-driven
98
98
9

Total

377

196

Table 3 Sample sizes for WGR comparisons between regular and BEAM-driven construction
works
Construction stage
Foundation
Building
Total

Regular
107
153
260

BEAM-driven
96
94
190

5. Data analysis
This section tests the hypotheses using the collected big data with the proper data analysis methods.
The data analysis is divided into two individual parts to test H1 and H2, respectively. Section 5.1 tests
H1 by comparing the UCC between regular and BEAM-driven projects, and Section 5.2 tests H2 by
comparing their respective CWM performance.
5.1 Comparing the UCC between regular and GBRS-driven projects
Using the formula described in Section 3.3, the UCC for foundation and building projects are
calculated and plotted in Figures 2 and 3, respectively. Figures 2 and 3 display the results of the
UCCs after a complicated process of data cleansing, sample selection, and calculation. It can be seen
from Figures 2 and 3 that the UCCs of BEAM-driven buildings appear generally larger than those of
the regular buildings, while the maximum of the latter is higher than the former. Whether the UCC
of BEAM-driven buildings are higher are examined statistically in the following.

UCC (HK$/m2)

100000

10000

1000

0

50

100

150

200

ID of project in its group
Regular foundation project

BEAM-driven foundation project

Figure 2 Comparison of the UCCs between regular and BEAM-driven foundation projects
10

UCC (HK$/m2)

1000000

100000

10000

1000

0

50

100

150

200

250

ID of project in its group
Regular building project

BEAM-driven building project

Figure 3 Comparison of the UCCs between regular and BEAM-driven building projects
The distributions of the UCCs for the four groups are plotted in Figure 4, and since all the groups
tend to follow a positively skewed distribution, the median UCCs instead of the mean UCCs are
adopted as a better representative of each group of regular and BEAM-driven green building projects.
The means and medians, along with difference of the median UCCs between BEAM-driven and
regular buildings are shown in Table 4. The result of the calculated UCCs is well in line with the
reported values from other sources. For example, Rider Levett Bucknall (RLB), a local surveying
firm publishing building costs regularly in Hong Kong, estimates the average UCC as between
HK$2,248 to HK$3,456 per square foot for a mid-rise apartment building providing homes of 650
to 750 square feet (Chow, 2017), and the average UCC is between 24,197 to 37,200 HK$/m2. The
results of this study indicate that the total UCC for a building is 25,865.46 HK$/m2 for regular
projects and 33,508.44 HK$/m2 for BEAM-driven projects.
The significance of the difference is statistically examined using Mood’s median test approach,
which is a nonparametric test that is used to test the equality of medians from two or more populations.
The null hypothesis is that there is no significant difference of the UCCs between regular and BEAMdriven buildings. The alternative hypothesis is that there is a significant difference in the UCC
between regular and BEAM-driven buildings. When a p-value is less than 0.05, the null-hypothesis
should be rejected, and the difference between the medians can be regarded as significant (Peng et
al., 2018). The p-values as displayed in Table 4 indicate that a statistically significant difference
11

exists in the UCC of BEAM-driven and regular buildings, at both foundation and building stages. It
was also found that the BEAM Plus accreditation reduces the cost of foundation works by
approximately 4.09%, while increasing the cost of building works by about 29.55%.
This study assumes the median foundation cost of BEAM-driven projects as F1, and that of regular
projects as F2. The median building cost of BEAM-driven projects is denoted by B1, and that of
regular projects by B2. As F1 and B1 both represent the median cost level for BEAM-driven projects
in Hong Kong, the foundation and building works for BEAM-driven projects at the median level can
be regarded as different stages of the same building, which is at the median cost level in Hong Kong;
the same applies to the regular projects. Foundation and building are the two main stages for a
building. Therefore, this study sums up F1 and B1, and F2 and B2 respectively to represent the total
median UCC for BEAM-driven and regular projects. The increased percentage of UCC can be
calculated as: (F1+B1)/(F2+B2)-1. The number is 24.15%, which means BEAM-driven buildings
generally cost 24% more than regular buildings. Therefore, H1 is supported by the statistical results.
An extra cost for pursuing a GBRS certificate is needed.

Figure 4 Histograms of the UCCs of regular and BEAM-driven buildings at foundation and
building stages
Table 4 Mood’s median test for comparing the UCC between regular and BEAM-driven buildings
Construction Regular (HK$/m2)
stage

BEAM-driven
(HK$/m2)

Median
difference

pvalue

Difference
significance
12

Mean
Median
Mean
Median
HK$/m2 %
7,050.56 4,946.77 5,484.00 4,744.60 -202.17 -4.09
37,481.65 25,865.46 36,130.35 33,508.44 7,642.98 29.05

Foundation
Building

0.0007 Yes
0.0031 Yes

5.2 Comparing CWM performance between regular and GBRS-driven buildings
According to the methodology presented in Section 3.4, the WGRs for foundation and building
projects are calculated and plotted in the order of significance in Figures 5 and 6 to demonstrate the
calculated results of WGRs of the selected samples. Relying on Figures 5 and 6 alone, it is difficult
to tell whether BEAM-driven projects have a greater WGR than the regular projects, as the
tendencies of their respective lines look similar. The differences of cost for both foundation and
building projects are statistically examined.

WGR (tonne/m2)

10

1

0

20

40

60

80

100

120

0.1

0.01

ID of project in its group
Regular foundation project

BEAM-driven foundation project

Figure 5 Comparison of the WGRs between regular and BEAM-driven foundation projects

13

WGR (tonne/m2)

10

1

0

20

40

60

80

100

120

140

160

180

0.1

0.01

ID of project in its group
Regular building project

BEAM-driven building project

Figure 6 Comparison of the WGRs between regular and BEAM-driven building projects
Before conducting the statistical comparisons, the distribution of the WGRs for the four groups are
plotted in Figure 7. Figure 7 shows all the groups tending to follow a positively skewed distribution,
and the median WGR rather than the mean WGR is shown to be a better representative of the waste
management performance for each type of BEAM-driven and regular construction works (Lu et al.,
2015; Lu et al., 2016a). The calculated means and medians of WGR are listed in Table 5. If a BEAMdriven building has lower WGR than a regular one, this building can be regarded as having achieved
a better CWM performance, probably driven by attempts to gain BEAM Plus credits.
The null hypothesis of Mood’s median test is that there is no significant difference in the WGRs
between regular and BEAM-driven buildings. The alternative hypothesis is that there is a significant
difference in the WGRs between regular and BEAM-driven buildings. The calculated differences
between medians of WGRs of BEAM-driven and regular buildings for both construction types are
listed in Table 5. The results (p-value>0.05, and WGR significance=No) show that the BEAM Plus
has non-significant effects on CWM in both foundation and building works. H2 is not supported. The
results indicate that BEAM Plus has not yet obviously differentiated green buildings from regular
buildings in its CWM performance. The samples constitute as large as 196 green buildings fail to
demonstrate the advantage of CWM performance when applying BEAM Plus. It would therefore
appear that this GBRS could not effectively incentivize the CWM aspect as part of its general aim
of pursuing sustainable development.

14

Figure 7 Histograms of the WGRs of regular and BEAM-driven projects at the foundation and
building stages
Table 5 Mood’s median test for comparing the WGRs between regular buildings and green
buildings
Construction
stage
Foundation
Building

Regular (ton/m2)
Mean
1.39
0.82

Median
1.06
0.35

BEAM-driven
(ton/m2)
Mean
Median
1.33
0.84
0.90
0.50

Median
difference
(ton/m2)
-0.22
0.15

pvalue

Difference
significance

0.1955
0.2406

No
No

6. Discussion
This study estimated an increase of 24.15% in the cost of developing green buildings. As stated in
H1, green buildings cost more than regular ones because developers need to add the cost of the effort
to achieve the green scopes in the GBRS. Compared with 1-11% extra cost driven by the LEED in
US (Miller, 2008) and 3-5% or more driven by the Green Star in Australia (Langdon, 2007), the extra
cost of green building driven by the BEAM Plus in Hong Kong seems to be higher. This is partly
due to the additional cost in Hong Kong’s highly compact economy of balancing the imports of green
materials and prefabricated elements for satisfying the green scopes. This study discovered that the
foundation stage of green buildings cost a little less but the building stage costs much more than
regular building. This is in part due to the achievable items in GBRSs that are far more relevant to
the building stage (i.e. superstructure) rather than the foundation stage. Most items are for the
superstructure, which constitutes a majority of attainable credits in the most important scopes, such
15

as energy saving and water conservation, where additional cost are needed for material procurement
and delivery, and installation. As these aspects seldom relate to costs at the foundation stage,
applying for green building certification costs far more at the building stage than at the foundation
stage. However, the important thing for developers to remember when they are considering whether
or not to apply for green building certification in Hong Kong, is that the overall construction costs
involved are approximately 24% higher than for construction of a regular building.
The BEAM Plus has a negligible influence on CWM performance according to the statistically
significant difference in the WGRs between regular projects and BEAM-driven projects, either at
foundation stage or building stage. This might due to the low total weighting of CWM-related items
(excluding those for demolition stage) where the credit allocation for waste reduction at the
foundation and building stages is only 2.18% under BEAM Plus. It is surprising to find that the
foundation stage generated a far larger amount of construction waste sent to disposal facilities than
the building works. This might due to the fact that foundation work includes not only piling but also
excavation, which generates a large amount of inert waste such as soil and rock. The large amount
of foundation waste disposed of at facilities is due to the difficulty of directly reusing inert waste on
the construction site itself.
From the findings of this research it can be concluded that green building accreditation using the
BEAM Plus generally increases the cost of construction by approximately 24%, while having a
negligible effect on CWM. The increased construction cost of green buildings will not be offset by
CWM as long as its corresponding setting in the BEAM Plus continues without incentivizing a
behavioural change. For improving CWM performance through promoting GBRSs, this study
suggests isolating foundation waste minimization as an additional item with more attainable bonuses
to encourage innovative solutions for minimizing construction waste. As there is great potential for
the reuse of foundation waste, it is suggested to develop a platform for a market wherein other
construction sites can share the waste materials. By doing so, contractors can save waste-disposalrelated fees, including waste transportation fees, facility disposal fees, labour fees, and the value of
the materials. This will also contribute to energy saving and carbon emission reduction in the material
flow (Shuai et al., 2018). As such, the extra construction costs for constructing green buildings can
be recouped from these cost saving and sustainable features harnessed from CWM improvements.
7. Conclusions

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This study examined the extra construction costs and benefits of green buildings, focusing on CWM
performance specifically. It did so by using the construction waste management and building data
covering Hong Kong projects in totality, instead of data samples collected from traditional
approaches, such as interviews and questionnaires. The results show that buildings applying for
BEAM Plus certification - the dominant GBRS in Hong Kong - generally cost approximately 24%
more than regular buildings. Constructing GBRS-driven buildings involves extra construction costs
because developers need to pay extra for the green features. Surprisingly, the BEAM Plus is shown
to have only a negligible effect on CWM. The statistically insignificant effect of green buildings on
CWM can be explained by the difficulties of conducting CWM, and the lack of incentives for doing
so at both the foundation and building stages.
This study makes two suggestions for improving the effects of GBRSs on CWM. Firstly, there should
be a finer approach for GBRSs to isolate foundation waste minimization as an item allocated with
more attainable credits and bonuses for innovation. Secondly, GBRSs should encourage contractors
to share waste materials for reuse rather than sending them straight to government disposal facilities.
It is not entirely the onerousness of GBRSs, but they can certainly play a role to encourage this waste
material sharing.
Finally, the limitations of this study and suggestions for further related research are as follows: Since
this study did not specifically consider sustainability benefits such as water and energy savings by
integrating them with construction costs, it is recommended that future research investigate a full
coverage of sustainability performance in order to provide a more comprehensive cost benefit
analysis; and, since the GBRS was examined with empirical data exclusively from Hong Kong,
future studies could examine green buildings’ CWM benefits in other jurisdictions using a similar
full-scale empirical data approach.
8. Acknowledgements
This research is jointly supported by the National Nature Science Foundation of China (NSFC)
(Project No.: 71273219) and the Hong Kong Research Grants Council (RGC) General Research
Fund (GRF) (Project No.: 17201917).
9. References
Bartlett, E., and Howard, N. (2000). Informing the decision makers on the cost and value of green
building. Building Research & Information, 28(5-6), 315-324.
17

Bianchini, F., and Hewage, K. (2012). How “green” are the green roofs? Lifecycle analysis of green
roof materials. Building and Environment, 48, 57-65.
Chang, N. B., Shoemaker, C. A., and Schuler, R. E. (1996). Solid waste management system analysis
with air pollution and leachate impact limitations. Waste Management and Research, 14(5),
463-481.
Chen, X., and Lu, W. (2017). Identifying factors influencing demolition waste generation in Hong
Kong. Journal of Cleaner Production, 141, 799-811.
Cheng, T. C., Cheng, C. H., Huang, Z. Z., and Liao, G. C. (2011). Development of an energy-saving
module via combination of solar cells and thermoelectric coolers for green building applications.
Energy, 36(1), 133-140.
Cole, R. J. (2003). Green buildings – Reconciling technological change and occupant
expectations. Buildings, Culture and Environment: Informing Local and Global Practices, 5782.
European Commission (2013). Construction and Demolition Waste (CDW). Available at:
http://ec.europa.eu/environment/waste/construction_demolition.htm. Accessed on 10/07/2017.
Formoso, C. T., Soibelman, L., De Cesare, C., and Isatto, E. L. (2002). Material waste in building
industry: Main causes and prevention. Journal of Construction Engineering and
Management, 128(4), 316-325.
Garcıa-Gil, J. C., Plaza, C., Soler-Rovira, P., and Polo, A. (2000). Long-term effects of municipal
solid waste compost application on soil enzyme activities and microbial biomass. Soil Biology
and biochemistry, 32(13), 1907-1913.
GovHK

(2017).

Waste

&

Recycling

in

Hong

Kong.

Available

at:

https://www.gov.hk/en/residents/environment/waste/wasterecycinhk.htm, May 2017, accessed
on 11/12/2017.
Gowri, K. (2004). Green building rating systems: An overview. ASHRAE Journal, 46(11), 56-59.
HKEPD (2005). NENT Landfill Extension - Feasibility Study. Available at:
http://www.epd.gov.hk/epd/english/nentlandfillext/nentlandfillext_maincontent.html,
accessed on 11/20/2017.
HKEPD

(2015a).

Monitoring

of

Solid

Waste

in

Hong

Kong.

Available

at:

https://www.wastereduction.gov.hk/sites/default/files/msw2014.pdf. Accessed on 08/09/2016.
HKEPD (2015b). Hong Kong waste treatment & disposal statistics. HKEPD. Available at:
http://www.epd.gov.hk/epd/english/environmentinhk/waste/data/stat_treat.html, accessed on
09/09/2016.
Langdon, D. (2007). Cost and Benefit of Achieving Green. Australia; 2007.
18

Li, M., and Yang, J. (2014). Analysis of interrelationships between critical waste factors in office
building retrofit projects using interpretive structural modelling. International Journal of
Construction Management, 14(1), 15-27.
Lu, W., and Tam, V. W. (2013). Construction waste management policies and their effectiveness in
Hong Kong: A longitudinal review. Renewable & Sustainable Energy Reviews, 23, 214-223.
Lu, W., Chen, X., Ho, D. C., and Wang, H. (2016a). Analysis of the construction waste management
performance in Hong Kong: the public and private sectors compared using big data. Journal of
Cleaner Production, 112, 521-531.
Lu, W., Chen, X., Peng, Y., and Shen, L. (2015). Benchmarking construction waste management
performance using big data. Resources, Conservation and Recycling, 105, 49-58.
Lu, W., Peng, Y., Chen, X., Skitmore, M., and Zhang, X. (2016b). The S-curve for forecasting waste
generation in construction projects. Waste Management, 56, 23-34.
Lu, W., Webster, C., Peng Y., Chen, X., and Zhang, X.L. (2016c). Estimating and calibrating the
amount of building-related construction and demolition waste in urban China. International
Journal of Construction Management, 17(1), 13-24.
McAllister, P. (2012). Studies of price effects of eco-labels in real estate markets: An ‘off the record’
record. http://goo.gl/wZk21G. Accessed on 2015.
Miller, N., Spivey, J., and Florance, A. (2008). Does green pay off? Journal of Real Estate Portfolio
Management, 14(4), 385-400.
Ministry of Environment of Japan (MoE) (2014). History and current state of waste management in
Japan. http://www.env.go.jp/en/recycle/smcs/attach/hcswm.pdf. Accessed on 21/09/2015.
Mor, S., Ravindra, K., Dahiya, R. P., and Chandra, A. (2006). Leachate characterization and
assessment of groundwater pollution near municipal solid waste landfill site. Environmental
Monitoring and Assessment, 118(1-3), 435-456.
Olanipekun, A. O., Chan, A. P., Xia, B., and Adedokun, O. A. (2018). Applying the selfdetermination theory (SDT) to explain the levels of motivation for adopting green building.
International Journal of Construction Management, 18(2), 120-131.
Peng, Y., Zhu, X., Zhang, F., Huang, L., Xue, J., and Xu, Y. (2018). Farmers' risk perception of
concentrated rural settlement development after the 5.12 Sichuan Earthquake. Habitat
International, 71, 169-176.
Poon, C. S., Ann, T. W., and Ng, L. H. (2001). On-site sorting of construction and demolition waste
in Hong Kong. Resources, conservation and recycling, 32(2), 157-172.
Prior, J. J. (1993). BREEAM/New Offices Version 1/93: an environmental assessment for new office
designs. Building Research Establishment Report 2nd edition 1993.
19

Roche, T. D., and Hegarty, S. (2006). Best practice guidelines on the preparation of waste
management plans for construction and demolition projects. http://goo.gl/LKxNsa. Accessed
on 21/09/2015.
Scofield, J.H. (2009). Do LEED-certified buildings save energy? Not really.... Energy and Buildings,
41(12), 1386-1390.
Shuai, C., Chen, X., Wu, Y., Tan, Y., Zhang, Y., and Shen, L. (2018). Identifying the key impact
factors of carbon emission in China: Results from a largely expanded pool of potential impact
factors. Journal of Cleaner Production, 175, 612-623.
USEPA (2016). Advancing Sustainable Materials Management: 2014 Fact Sheet. Available at:
https://www.epa.gov/sites/production/files/2016-11/documents/2014_smmfactsheet_508.pdf.
Accessed on 06/07/2017
Wu, P., and Low, S. P. (2010). Project management and green buildings: Lessons from the rating
systems. Journal of Professional Issues in Engineering Education and Practice, 136(2), 64-70.
Wu, Z., Shen, L., Ann, T. W., and Zhang, X. (2016). A comparative analysis of waste management
requirements between five green building rating systems for new residential buildings. Journal
of Cleaner Production, 112, 895-902.
Zhang, Y., and Altan, H. (2011). A comparison of the occupant comfort in a conventional high-rise
office block and a contemporary environmentally-concerned building. Building and
Environment, 46(2), 535-545.
Zuo, J. and Zhao, Z. (2013). Green building research–current status and future agenda: A review.
Renewable and Sustainable Energy Reviews, 30(3), 271-281.

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