Co-benefits of Green Buildings - UNU-IAS - United Nations University

UNU-IAS Working Paper No. 171
Co-Benefits of Green Buildings and the Opportunities
and Barriers Regarding their Promotion
Osman Balaban
March 2013

Acknowledgements
This research was supported by the United Nations University Institute of Advanced Studies
(UNU-IAS) and the Scientific and Technological Research Council of Turkey (TUBITAK).
The author is grateful to both institutes for their support and contribution.
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Abstract
The lifecycle of a building usually results in significant amounts of energy and resource
consumption as well as considerable environmental footprints. In almost every country,
buildings are among the major sources of CO 2 emissions, waste generation and water
consumption. The concept of green buildings, which is based on the application of
sustainability principles to building design, construction and management processes, is a
recent response to reduce the overall impacts of buildings on natural environment. Although
there has been important progress in development of the green buildings concept,
implementation of it is not widespread yet. In both developed and developing countries, the
greening of buildings has not taken place on a wider scale, owing to significant challenges. In
this respect, further research is required to develop the conceptual and especially the practical
underpinnings of green buildings.
In view of this background, the main purpose of this working paper is to understand the
environmental benefits of green buildings as well as the opportunities and barriers regarding
their promotion. In particular, based on a case study in Tokyo and Yokohama, this paper (a)
discusses the most common green technologies and measures used in the Japanese building
sector, (b) quantifies the major environmental benefits of the case study buildings, and (c)
highlights the opportunities and barriers to promote the construction of green buildings in
Japanese cities.
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1. Introduction
Climate change is one of the greatest challenges of the twenty-first century. It is likely to
cause severe impacts on human life and settlements, including rise in sea levels, extreme
weather events, flooding, heat waves, drought, air pollution and water shortage. The
Intergovernmental Panel on Climate Change (IPCC, 2007) states that current climate change
is anthropogenic and unequivocal. This implies that even with the full implementation of the
most effective mitigation measures, it will not be enough to stop global warming and avoid
climate change impacts (Klein et al., 2007). Therefore, along with mitigation actions to keep
global warming at relatively lower levels, adaptation actions are also required to reduce the
climatic vulnerabilities of human settlements (IPCC, 2007).
Cities can play a crucial role in tackling climate change through mitigation and adaptation
actions. First of all, cities contribute much to the causes of climate change in terms of
greenhouse gas emissions (GHGs), land-use change and deforestation. Second, cities
accommodate more than half of the world’s population and critical economic activities.
Climate change-related events will thus disturb the lives of a large part of the world’s
population and key economic activities. On the other hand, despite being part of the problem,
cities can in fact be the critical part of the solution based on their inherent advantages. The
high concentrations of people and economic activities in cities could result in economies of
scale, proximity and agglomeration, all of which can help develop effective and low cost
solutions to reduce energy use and associated emissions (UN-HABITAT, 2011).
In view of the critical links between cities and climate change, it is widely accepted that most
of the challenges posed by climate change could be addressed through policy responses in
cities (Prasad et al., 2009). A significant part of such policy responses is related to urban
spatial processes, and refers to adjustments in key spatial structures and elements in cities.
Spatial policy responses have long term effects and could help achieve mitigation and
adaptation goals simultaneously. For instance, green spaces like urban forests, trees and
permeable surfaces can mitigate emissions through carbon sequestration and also avoid
certain impacts of climate change, such as heat stress, air pollution and flood risks (Gill et al.,
2007; Yang et al., 2005; Novak and Crane, 2002). Buildings-related actions and measures
constitute an essential part of spatial policy responses. This is due to the increasing
contribution of urban buildings to ongoing climate change and to people’s vulnerabilities to
climate change. Buildings are among the major sources of excessive resource and energy
consumption, and thereby carbon emissions in cities. Along with one-third of global energy
end use, the building sector is responsible for more than a third of global resource
consumption, including 12 per cent of all fresh water use, and generates approximately 40 per
cent of the total volume of solid wastes in the world (Rode et al., 2011). Furthermore,
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uildings that are located on hazardous sites and poor in quality are highly vulnerable to
climate change and thus their inhabitants are exposed to high climatic risks.
The concepts of sustainable construction and green building are the recent responses to
address environmental problems that stem from buildings and reduce the overall impacts of
the building sector on the natural environment. In the last two decades, in both developing
and developed countries, the attention on construction of green buildings and retrofitting of
existing buildings by using low-carbon and green technologies has grown considerably. One
major outcome of this recent development is the establishment of green building councils and
the introduction of green building certification systems that aim to assess environmental
performance of new and retrofitted buildings and certify best practices. The reflection of this
trend in Japan can be seen in the example of the CASBEE system. Nevertheless, despite the
progress in development of concepts of green and sustainable buildings, the greening of
buildings has not taken place on a wider scale in neither developed nor developing countries
(Rode et al., 2011). Especially the energy performance of the building sector is still far from
sustainable (Nishida and Hua, 2011). Challenges regarding widespread implementation of the
green buildings concept need to be specified and removed by academic and policy-oriented
research as well as by relevant policy interventions. The main purpose of this paper is to
understand environmental benefits of green buildings as well as opportunities and barriers
regarding their promotion. Based on a case study covering several buildings in Tokyo and
Yokohama, the paper (a) discusses the most common green technologies and measures used
in the Japanese building sector, (b) quantifies the major environmental benefits of the case
study buildings, and (c) highlights the opportunities and barriers to promote the construction
of green buildings in Japanese cities.
The paper comprises six main sections. The following two sections present a literature review
on the relationship between climate change and the building sector, and on the concept of
green buildings. In section four, the geographical context of the research is discussed. Legal
and policy frameworks that regulate green building construction in Japan are explained in this
section. In the fifth section, explanations on details of research methodology are given.
Sections six and seven present the findings of the research in terms of co-benefits of green
buildings as well as opportunities and barriers regarding promotion of green buildings.
2. Buildings and Climate Change
Buildings have a key role to play in climate change mitigation. In almost every country, a
significant part of total greenhouse gas emissions (GHGs) stem from buildings. GHGs from
buildings are mainly related to electricity use for lighting and appliances, and energy use for
indoor heating and cooling. Approximately one-third of global energy end-use takes place
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within buildings (IEA 2010 cited in Rode et al., 2011). Besides, almost 60 per cent of the
world’s electricity consumption takes place in residential and commercial buildings, bearing
in mind the variations across geographical locations (IEA 2009 cited in Rode et al., 2011).
According to IPCC estimates, emissions from residential and commercial buildings
correspond to 8 per cent of the world’s total global GHG emissions (IPCC, 2007). As
opposed to developing countries, the share of buildings in total energy consumption and
associated GHG emissions are higher in developed countries. For example, residential and
commercial buildings are responsible for 37 per cent of energy-related CO 2 emissions in the
United States (McMahon et al., 2007). In the European Union, 40 per cent of primary energy
consumption takes place in buildings and this amount of energy use in the building stock
generates 25 per cent of total CO 2 emissions (Uihlein and Eder, 2010). On the other hand, the
building sector in China, for example, is generally responsible for one-quarter of total energy
consumed in the country (Jiang and Tovey, 2009). However, developing countries are
expected to surpass developed countries in the building sector’s share of total energy
consumption and GHG emissions owing to the fact that urban population growth in the near
future will mostly take place in developing countries. Annual growth rate of new commercial
and residential building construction is around 7 per cent in China and 5 per cent in India and
Southeast Asia, as opposed to only 2 per cent in the developed world (Baumert et al., 2005
cited in Rode et al., 2011).
Despite being one of the major emitters of GHGs, the building sector also holds the greatest
potential to mitigate GHG emissions. According to calculations made by the IPCC (2007),
the global mitigation potential in the building sector ranges between 5.3 and 6.7 GtCO2-eq/yr
by 2030, and this potential could be achieved with a cost per tCO2-eq of no more than
USD100 (Figure 1). Furthermore, most of this potential could be realized at a cost of less
than USD 20 per tCO2-eq. In this sense, the building sector has by far the greatest potential
compared to other sectors (Figure 1).
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Figure 1. Mitigation Potentials of Major Sectors (IPCC, 2007)
At the same time, buildings are also important for adaptation strategies. Residential and
commercial structures are expected to be exposed to substantial damage with increasing
occurrence of climate change-related hazards and disasters (UN-HABITAT, 2011). In cities
of least developed and developing countries, where the scale of informal settlements and lowquality
housing is huge, buildings and thereby their inhabitants are highly vulnerable to likely
impacts of climate change, such as extreme weather events, flooding, and water and power
shortages. For instance, it is estimated that 70–80 per cent of all housing construction in
Indonesia is informal, and 82 per cent of the population in Lima (Peru) are classified as urban
poor and live in slums (Malhotra, 2003). In a similar vein, nearly half of the building stock in
major Turkish cities has been built illegally and informally (Balaban, 2012). Therefore
relevant policy responses and measures in the building sector not only mitigate climate
change but also help the building sector adapt to adverse impacts of climate change.
One major field of such policy responses and measures is sustainable construction, or
specifically, construction of green buildings. Construction of green buildings is accepted as
an important strategy to reduce carbon emissions by reducing energy demand of buildings
and also by increasing the efficiency of energy and resource use (Larsen et al., 2011). Besides,
green building strategies have the potential to work for both mitigation and adaptation goals.
For example, rooftop gardens and green curtains reduce energy consumption for indoor
cooling, remove emissions through carbon sequestration, and help address climate change
impacts like heat waves and urban heat island effect. Likewise, renewable energy strategies
not only reduce carbon emissions but also make buildings more resilient to power outages
(Larsen et al., 2011).
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3. The Concept of Green Buildings
Greening of buildings could be an essential strategy to address global environmental
challenges, particularly climate change. There has been considerable progress in design and
construction strategies of green buildings, also known as low-energy buildings, during the
last couple of decades. In general, the concept of green buildings refers to the efforts to
change the way the built environment is designed, constructed and operated (Larsen et al.,
2011). The main motivation behind the concept is to make buildings more energy and
resource efficient and to reduce their impacts on the environment by means of relevant design
and construction techniques as well as low-carbon technologies. There are various definitions
of green buildings (also known as sustainable buildings or low-carbon buildings) and a
consensus on the definition is yet to be reached. The International Energy Agency defines
green buildings as buildings with increased energy efficiency, reduced water and material
consumption, and improved health and environment conditions (Laustsen, 2008). There are
other definitions that take into consideration some broader aspects like economic and social
gains along with minimal environmental impacts. For instance, Rode et al. (2011) include not
only the environmental dimensions, but also economic dimensions (such as energy savings,
cost of greening, payback periods, productivity and job creation) and social dimensions (such
as indoor pollution and health) into the definition of green buildings. In this paper, the
concept of green buildings is relatively narrow and refers to buildings constructed with
special design techniques and low-carbon technologies and measures to reduce energy and
resource consumption, and registered by green building certification systems.
With the development of the concepts of sustainable construction and green buildings since
the 1990s, green building councils have been established in several developed countries in
order to promote sustainable construction and green buildings, mainly through building
assessment methods. These methods generally include guidelines for assessing the
environmental performance of buildings and certification systems to determine or benchmark
building performance. The Building Research Establishment Environmental Assessment
Method (BREEAM), which was developed by the Building Research Establishment in 1990
in the UK, is the first comprehensive building performance assessment method, and still
remains the most widely used, as it influenced countries and cities like Canada, Australia and
Hong Kong (Ding, 2008). The leadership in energy and environmental design (LEED)
programme developed by the U.S. Green Building Council is another significant example.
The LEED programme includes a graduated rating and certification system (certified, silver,
gold and platinum) for environmentally-friendly design and has certified 36 million m 2 of
commercial and public sector buildings within five years after its initiation (McMahon et al.,
2007). There has been a growing interest in construction and promotion of green buildings in
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Japan, where the comprehensive assessment system for building environmental efficiency
(CASBEE) has been developed and updated since 2001. As voluntary schemes, green
building assessment methods and certification systems can be effective in overcoming some
barriers and in raising awareness of how to address climate change and environmental
problems by means of measures and strategies in the building sector.
4. The Japan Context
Greenhouse gas emissions in Japan have increased almost 9 per cent from levels of 1990,
reaching 1.37 billion tonnes by 2007 (Takemoto, 2011). Most of this increase has taken place
in residential and commercial sectors, where household and commercial emissions have risen
37 per cent and 45 per cent respectively (Nakagami, 2011). Both residential and commercial
buildings are major sources of increasing emissions. For instance in Tokyo, where 63 million
tonnes of CO 2 were emitted in 2008, residential buildings along with large commercial and
industrial buildings are responsible for almost half of these emissions (TMG, 2011a). More
specifically, 1,300 large commercial and industrial buildings 1 emit 40 per cent of all CO 2
emissions from commercial and industrial sectors in the Tokyo metropolitan area (Nishida
and Hua, 2011). Therefore, one major focus of climate change mitigation efforts in Japanese
cities is the building sector.
Several targets for reducing GHG emissions have been set by public authorities in Japan. Due
to the commitments of the Kyoto Protocol, Japan has to reduce GHG emissions by 6 per cent
from 1990 levels between 2008 and 2012. Furthermore, in September 2009, former Japanese
prime minister, Yukio Hatoyama, announced that Japan would aim to cut GHG emissions by
25 per cent from 1990 levels by 2020 (Takemoto, 2011). This target, which was soon named
the Hatoyama Initiative, is one of the four main pillars of the Action Plan for Achieving a
Low-Carbon Society enacted by the Japanese government in 2008 in line with the outcome of
the G8 Hokkaido Toyako Summit. The national target set by the Hatoyama Initiative has
been accepted by public and private sectors, and several policy initiatives and legal
frameworks have been introduced by national and local governments in order to achieve that
target as well as to reduce the overall environmental footprints of the country.
Among the most crucial of these policy and legal frameworks are Action Plan for Achieving
a Low-Carbon Society (2008), Law Concerning the Promotion of Measures to Cope with
Global Warming (1998) and Kyoto Protocol Target Achievement Plan (Takemoto, 2011). In
some of the climate change-related policy and legal frameworks, there are regulations and
measures for energy and resource efficiency in the building sector. When institutional aspects
1 Large commercial and industrial buildings refer to the buildings, in which annual energy consumption is more than 1,500
kiloliters of crude oil equivalent.
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of building energy and resource efficiency are considered, responsibilities are shared by two
ministries, namely the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) and
the Ministry of Economy, Trade and Industry (METI). Besides, there are also leading
initiatives and programmes introduced by local governments, such as the Cap and Trade
Programme of Tokyo Metropolitan Government (hereafter TMG) and CASBEE Yokohama
of City of Yokohama (hereafter COY).
The Law Concerning the Promotion of Measures to Cope with Global Warming (hereafter
Act on Promotion of Global Warming Countermeasures) was enacted in 1998 after the Kyoto
Conference. This Act aims to attain targets under the Kyoto Protocol and to take necessary
measures to control GHG emissions by formulating a plan, the Kyoto Protocol Target
Achievement Plan (Takemoto, 2011). The act also outlines the roles that should be played by
public, private and non-governmental sectors in order to facilitate the development and
implementation of the target achievement plan. Since 1998, Act on Promotion of Global
Warming Countermeasures has been amended several times in order to reinforce it in a way
that each stakeholder can actively promote countermeasures against global warming. The
June 2008 revision has brought about significant regulations into the act in terms of measures
to improve energy efficiency and savings in the building sector. A new system has been
introduced to calculate, report and announce the emissions from companies and premises
(including buildings) in industrial, residential and commercial sectors (Takemoto, 2011).
The Act on the Rational Use of Energy (hereafter Energy Saving Law) is the major legal
framework that regulates energy efficiency and savings in the Japanese building sector. Most
of the energy-related regulations concerning buildings fall under this law, which is closely
connected to the Act on Promotion of Global Warming Countermeasures. These two laws are
sometimes likened to “two wheels of the same cart”. Energy Saving Law was first enacted in
1979 in response to the oil crisis of the late 1970s. Despite its original focus on economizing
the use of oil during the crisis, the law at present aims to regulate the use of energy in order to
limit GHG emissions and encourage the private sector to undertake actions to mitigate global
warming (Takemoto, 2011). After substantial revisions in 2008, firms and companies
undertaking new construction and renewing or extending existing buildings over 300 m 2
(including both residential and commercial) are obliged to use energy-efficient design
techniques and technologies and also to submit a report to public authorities about their
energy conservation measures before any action. In addition, the revised law requires
companies constructing residential buildings to label the energy efficiency of the houses
(Takemoto, 2011). Energy Saving Law also defines standards, which are not mandatory but
voluntary, to improve energy performance of residential and commercial buildings (ABC,
2007). The commercial building energy standard is performance-oriented and based on the
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use of two indicators for assessing the energy performance of a building’s envelope and
equipment (Box 1).
Box 1: Indicators for assessing energy performance of a building
PAL = CL / A
CEC = EC a / EC s
PAL: Perimeter Annual Load (indicator for building envelope)
CL: Annual space conditioning load in the perimeter zone (MJ/year)
A: Area of perimeter zone (m 2 )
CEC: Coefficient of Energy Consumption (indicator for building equipment)
EC a : Actual energy consumption (MJ/year)
EC s : Standard energy consumption (MJ/year)
Source: ABC, 2007
TMG has taken the lead in Japan in addressing buildings-related environmental problems by
means of various measures, schemes and programmes. The Cap and Trade Programme and
the Green Building Programme are the most important policy frameworks in this respect at
the moment. In 2000, the CO 2 Emissions Reduction Programme was introduced by TMG as
part of the new Environmental Security Ordinance. With this programme, large facilities with
high CO 2 emissions were obliged to report their CO 2 emissions data to TMG along with their
plans to reduce emissions in three years (TMG, 2011a). The reporting system was mandatory,
but the reduction commitments were on a voluntary basis (Nishida and Hua, 2011). The 2005
revision to the programme has added a rating system and a web-based public reporting
system, both of which gave TMG more ability and opportunity to issue guidance (TMG,
2011a). The mandatory reporting programme has led the owners and managers of large
facilities in Tokyo to be more aware of their energy consumption patterns and the need for
energy conservation (TMG, 2011a). On the other hand, the voluntary scheme on reduction
commitments resulted in low reduction in emissions from the target facilities (Nishida and
Hua, 2011). The shortcomings of the voluntary programme and TMG’s ambitious target of
reducing GHG emissions by 25 per cent from 2000 levels by 2020 have led TMG to
introduce the Cap and Trade Programme as a mandatory emissions reduction system.
The Tokyo Cap and Trade Programme (hereafter TCTP) was launched in April 2010, as the
world’s first city-based cap and trade programme. The TCTP covers 1,300 large CO 2 -
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emitting facilities that consume more than 1,500 kiloliters of crude oil equivalent annually in
commercial and industrial sectors (Nishida and Hua, 2011). Among these facilities, 1,000 of
them are office buildings, public buildings and commercial facilities, and 300 are factories
and other facilities in the industrial sector (TMG, 2011a). Almost all of the high-rise
buildings in the Tokyo metropolitan area are included in the TCTP. The TCTP requires
targeted facilities to reduce their emissions by 25 per cent in two five-year periods from 2010
to 2020. During the first compliance period (2010–2014), the targeted factories and office
buildings are obliged to achieve a reduction of 6 per cent and 8 per cent respectively (TMG,
2011a). The cap for the targeted facilities for the second compliance period (2015–2019) is
higher, currently set as 17 per cent reduction (Nishida and Hua, 2011). The TCTP also
includes an emission trading system, which enables facility owners to sell the excess
reductions above their annual obligations or purchase others’ excess reductions (Nishida and
Hua, 2011).
While the TCTP targets existing buildings, the Tokyo Green Building Programme (hereafter
TGBP) focuses on new buildings with the aim of improving environmental performance of
new building construction in the Tokyo metropolitan area. The TGBP originally developed to
cover all large new buildings with a total floor area of over 10,000 m 2 (TMG, 2011a). With
the 2010 revision, the scope of the programme has been increased to cover all new buildings
with total floor space exceeding 5,000 m 2 (TMG, 2011a). Owners or developers of all new
buildings in Tokyo are obliged to conduct an environmental performance evaluation and to
publish the Building Environmental Plan, which presents the evaluation results on TMG’s
website (TMG, 2011b). The major aims of the TGBP are to encourage building owners to
apply environmentally-friendly design principles based on TMG guidelines, and to create a
market where green buildings are highly valued (TMG, 2011a and 2011b). Since the
initiation of the TGBP, more than 1,500 buildings have prepared and disclosed their
environmental plans (TMG, 2011b).
There are also several voluntary and non-regulatory programmes to promote green and
sustainable buildings in Japan. Among such programmes is CASBEE, which stands for
Comprehensive Assessment for Building Environmental Efficiency. CASBEE is Japan’s
green building evaluation and rating system developed by the Japan Sustainable Building
Consortium as part of a joint industrial/government/academic project supported by the MLIT.
Like its counterparts in different parts of the world, it is a support tool and a method to assess
the environmental performance of buildings of different types. The CASBEE system was
developed during the early 2000s and its first assessment tool that targets office buildings was
introduced in 2002. This was followed by CASBEE for New Construction in 2003, CASBEE
for Existing Building in 2004 and CASBEE for renovation in 2005. The CASBEE system
evaluates a building from two different points of views: environmental quality and
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performance (Q), and environmental load on the external environment (L). The overall
CASBEE rank is the proportion of the quality value (Q) to load value (L). Based on the
overall rank received after evaluation, CASBEE certifies buildings’ environmental
performance according to a five-grade system, in which “S Rank” is the best.
In 2008, CASBEE was revised in a way to add an explicit CO 2 reduction target and initiative
to the system. The life cycle CO 2 assessment (LCCO 2 ) concept and tools were introduced to
evaluate CO 2 emissions during the entire lifecycle of the building. The newer versions of
CASBEE assessment tools include explicit references to climate change mitigation measures.
In particular, building owners and managers are asked to calculate the likely CO 2 emissions
of their buildings by using the calculation methods provided with the CASBEE tools. The
benchmarking level of CO 2 emissions against which building owners and managers will
assess their buildings’ performance is set as 120 kg-CO 2 /m 2 /year in the 2010 edition of
CASBEE for New Construction based on the Energy Saving Law.
Although CASBEE is developed by the MLIT at the national level, local governments are
allowed to develop their own CASBEE tools by tailoring the main tools into their local
situation. To date, 23 local governments have developed their own CASBEE and have started
to ask building owners and developers to conduct CASBEE evaluation and submit the results.
CASBEE is a voluntary and non-regulatory mechanism which can apply to both public and
private sectors. Yokohama city is taking an active part in this respect and have introduced
CASBEE Yokohama in 2005. According to CASBEE Yokohama, owners of buildings that
exceed a total floor space of 2,000 m 2 are obligated to conduct self assessments based on the
CASBEE Yokohama guidelines and report the results to COY during the planning stage of
construction. From July 2005 to March 2008, 329 self-assessment reports were submitted to
COY. The city also introduced the CASBEE certification system in order to promote
corporate social responsibility (CSR) of building owners towards environmental issues. The
certification system is not mandatory. Only building owners, who are interested in the
certification, can apply to COY to have their buildings certified based on assessments by
academic experts.
Despite the introduction of several policy and legal frameworks to promote energy efficiency
in buildings as well as construction of green buildings, limited progress has been achieved in
reducing Japan’s total energy consumption in the building sector. This is due to a number of
financial, social and political challenges, some of which this research attempts to uncover and
discuss.
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5. Research Methodology
5.1 Data Collection
This paper presents the findings of a case study research. Bearing in mind the specificities of
the cases examined, a case study method helps drawing policy implications and lessons based
on empirical evidence from practical cases (Ragin and Becker, 1992). In this respect, the
research aims to learn from Japan’s experience on green buildings and develop policy
implications based on the lessons learnt.
The research has been carried out in several steps, starting with literature review on the
relationship between the building sector and climate change, and on the concept of green
buildings to establish the theoretical and policy backdrop to the paper. In addition, the policy
and legal frameworks that regulate green buildings and energy efficiency and savings in the
Japanese building sector have been examined. At this step, necessary information was
obtained from academic journals, books, conference proceedings, and governmental and nongovernmental
documents.
The data and information used to analyse the case study buildings were mainly obtained
through interviews. 11 interviews with 24 people were conducted to collect quantitative data
and qualitative information. Interviewees were (a) building owners (representatives of
companies owning the buildings), (b) building managers (representatives of companies
managing the buildings), (c) design and construction experts, (d) city officials and (e)
academics.
Main inquiries of the interviews were as follows:
Current status of green building construction in Japan: good examples
Major policy and legal frameworks that regulate and promote green building
construction
Most common eco-friendly design elements, green technologies and energy-saving
measures currently being applied in the Japanese building sector
Major barriers and challenges to promote green building construction in Japanese
cities
Data on energy and resource consumption in case study buildings
5.2 Case Study Selection
This research is based on examination of seven case study buildings, all of which are located
in the Tokyo Metropolitan Area, including cities of Tokyo and Yokohama. Tokyo
Metropolitan Area (TMA) constitutes an important context for such research due to two
reasons. First of all, TMA is the largest urban agglomeration in Japan (also in the world),
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where crucial economic activities, powerful public and private institutions and some key
international organizations are concentrated. The headquarters of the biggest Japanese
companies together with some international ones are located in TMA, which led the area to
be ranked as the largest urban agglomeration by GDP in the world in 2008. 2 Besides, the
metropolitan area also accommodates several leading academic and research institutions
working in close collaboration with private and public agencies. The city governments of
Tokyo and Yokohama have been taking the lead among Japanese cities to develop policies
for effective and better management of urban development with particular attention on
environmental issues. Therefore, TMA showcases Japan in many respects including new and
innovative urban policies and state-of-the-art urban technologies. Considering the current
development in construction of green and sustainable buildings in Tokyo and Yokohama,
TMA has been selected as the case study area of this research.
Case study buildings were selected based on certain features. In particular, buildings with
different features, occupation statuses and sizes were selected and examined in order to
facilitate a comparable analysis. Four of the case study buildings were green buildings,
whereas the rest were not designed and constructed as green buildings but retrofitted to make
them low-carbon and environmentally-friendly. Particular attention was paid to select green
buildings subjected to green building certification evaluations. The four green buildings
visited had been evaluated and certified by the CASBEE system. Table 1 presents the key
information on case study buildings. As seen in the table, buildings vary in their occupation
status, size, function and location.
Table 1: Detailed Information on the Case Study Buildings 3
Building
Name
Occupation Status Quality Status
Total
Floor
Space
Functional
Status
A Owner Occupied Green Building 92,000 m 2 Office Building
with Public
Gallery
B Tenant Occupied Green Building 95,220 m 2 with Commercial
Office Building
C
D
New Building (not
in use)
New Building (not
in use)
Green Building 114,539 m 2
Facilities
Office Building
with a Shopping
Mall
Location
Yokohama
Yokohama
Yokohama
Green Building 90,134 m 2 with Commercial and Public Facilities
Office Building
2
This is according to a research published by PricewaterhouseCoopers, which can be accessed from the following link:
https://www.ukmediacentre.pwc.com/imagelibrary/downloadMedia.ashx?MediaDetailsID=1562
3 Due to the request by the owners and managers of the case study buildings, the buildings’ names are undisclosed and each
case study building is named with a letter.
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E
F
G
Tenant Occupied
Tenant Occupied
Tenant & Owner
Occupied
Non-Green
Building
Non-Green
Building
Non-Green
Building
393,000 m 2 Mixed-Use
Building
Yokohama
82,602 m 2 Office Building Tokyo
25,331 m 2 Office Building Tokyo
Data availability and accessibility were also significant factors that influenced selection of
case study buildings. Building owners and managers in Japan usually regard quantitative data
on energy and resource consumption in their buildings as commercial secrets and tend not to
share this data with third parties. Besides, there were challenges to reach the required
quantitative data through city governments. Our interviewees from city governments
mentioned that building owners, in most cases, add confidentiality notice for energy and
resource consumption data they share with city governments. These challenges made it
difficult to increase the sample size of the empirical research. Attempts have been made to
get in touch with the owners or managers of various buildings in TMA in order to make
research interviews and collect data. Priority was given to buildings with accessible and
available contact persons as well as required data.
5.3 Data Analysis
The co-benefits of case study buildings were calculated in terms of environmental benefits
and economic benefits. Environmental benefits comprise (a) specific energy consumption, (b)
CO 2 emissions, and (c) water savings. Economic benefits are two-fold: cost-savings from
reduced energy consumption and potential monetary income in case reduction in CO 2
emissions are subjected to carbon trading.
Specific energy consumption is the primary energy use per square metre per year in a
building. Specific energy consumption was calculated as per the equation given in Box 3.
However, the prerequisite to calculate specific energy consumption in a building is
calculation of primary energy use in that building. The data on energy consumption collected
from building owners and managers during the field work was in the form of “site energy”,
which is the energy directly consumed by the end user. In order to make accurate calculations
on total energy consumption of buildings, “site energy” had to be converted into “primary
energy”, which takes into account the energy consumed in the production and delivery of
energy used at the end point. 4 Therefore, primary energy refers to the sum of site energy and
the energy consumed to produce and deliver the site energy. Primary energy conversion
factors were used to convert the amounts of different forms of fuels consumed on site into
4 Definitions of site and primary energy could be found on the following link:
http://www.eia.gov/emeu/consumptionbriefs/cbecs/cbecs_trends/primary_site.html
15

primary energy amount. In this research, the following primary energy conversion factors
were used: 9.76 for electricity and 1.36 for heated and cold water. Details of calculation of
primary energy use are given in Box 2. The data used to calculate primary and specific
energy consumption of case study buildings (total use of different energy sources on site,
total floor area of the building and the conversion factors) were collected during the research
interviews.
Box 2: Equation to calculate primary energy use of a building
P aeu = [(El ac *9.76)+(HW ac *1.36)+(CW ac *1.36)]
P aeu : Primary annual energy use (MJ/yr)
El ac : Total annual electricity consumption (kWh/yr)
HW ac : Total annual heated water consumption (MJ/yr)
CW ac : Total annual cold water consumption (MJ/yr)
9.76 is the primary energy conversion factor for electricity
1.36 is the primary energy conversion factor for heated and cold water
Box 3: Equation to calculate specific energy consumption of a building
S ec = P aeu / FA b
S ec : Specific energy consumption (MJ/m2/yr)
P aeu : Primary annual energy use (MJ/yr)
FA b : Floor area of building (m 2 )
In a similar vein, CO 2 emissions were calculated per square metre per year based on total
energy use in a building that consists of total annual electricity consumption and annual
energy consumption for heating and cooling. To make this calculation, specific CO 2 emission
factors for electricity and natural gas reported by Tokyo Electric Power Company (TEPCO)
and Tokyo Gas were used. According to the TEPCO Environmental Indicator Performance
Record, CO 2 emission factor for Tokyo electricity (including Yokohama city) is 0.384 kg-
CO 2 /kWh for 2009. 5 Likewise, Tokyo Gas Group CSR Report 2011 indicates the CO 2
emission factor for Tokyo electricity as 0.384 kg-CO 2 /kWh for 2010. Besides, in this report,
CO 2 emission factor of steam and cooling water in the Tokyo area (including Yokohama) is
5 The report could be accessed through the following link:
http://www.tepco.co.jp/corporateinfo/company/annai/shiryou/images/kankyo.pdf
16

listed as 0.057 kg-CO 2 /MJ for the period of 2007–2010. 6 CO 2 emissions of case study
buildings were calculated as per the equation given in Box 4.
Box 4: Equations to calculate CO 2 emissions of a building
CO 2 E total = [(El ac *0,384)+(HW ac *0,057)+(CW ac *0,057)] / 1.000
CO 2 E specific = CO 2 E total / FA b
CO 2 E total : Total annual CO 2 emissions of the building (tonnes/yr)
CO 2 E specific : Total annual CO 2 emissions per square metre of the building (kg/m 2 /yr)
EL ac : Total annual electricity consumption (kWh/yr)
HW ac : Total annual heated water consumption (MJ/yr)
CW ac : Total annual cold water consumption (MJ/yr)
FA b : Floor area of the building (m 2 )
0,384 kg-CO 2 /kWh is the CO 2 emission factor of electricity in Tokyo metropolitan area
0,057 kg-CO 2 /MJ is the CO 2 emission factor of steam and cooling water in Tokyo
metropolitan area
Water savings, as the third form of environmental co-benefits in this research, refer to the
amount of water recovered, recycled and reused in the building on an annual basis. This data
was provided by the owners and managers of case study buildings interviewed during the
field work. Therefore, no calculations were made regarding water savings of the buildings
examined.
The specific energy consumption and CO 2 emissions figures of case study buildings were
evaluated against benchmark levels in order to see the extent to which energy consumption
and CO 2 emissions had been reduced in the buildings examined. Benchmark levels are the
average specific energy consumption and average CO 2 emissions per square metre in tenantoccupied
office buildings in Tokyo in 2005. Benchmark values were taken from an official
document provided by the TMG, and values are as follows: 2518 MJ/m 2 /yr and 107
kg/m 2 /yr. 7 These benchmarks are widely used by building owners and managers to assess the
performance of their buildings that are included in the Cap and Trade and Green Buildings
Programmes of TMG. 8 Last but not least, benchmarks for Tokyo could also be used for
assessing the performance of buildings in Yokohama, as both cities are part of the TMA and
have similar climatic conditions.
6 The report could be accessed through the following link: http://www.tokyo-gas.co.jp/csr/report_e/environment/06_09.html
7 The TMG’s official document from which benchmarks are taken could be accessed from the following link:
http://www.env.go.jp/council/06earth/y060-54/mat03_1-9.pdf
8 Similar evaluation based on these benchmarks could be seen in TMG (2011b).
17

As the second form of co-benefits on which this research focuses, monetary gains were
calculated by using total amount of energy savings and CO 2 emissions reduction in the case
study buildings. This calculation was based on the assumptions that energy savings bring
monetary benefits to the users of buildings and that emission reductions could be subjected to
carbon trading to gain economic benefits. In order to calculate the economic benefits, unit
prices of electricity, steam and cold water (for indoor heating and cooling) were used. Unit
prices of electricity (JPY18/kWh) and heating and cooling energy (JPY5.6/MJ) were taken
from reports by the Energy Conservation Center of Japan (ECCJ) and the Minato Mirai 21
District Heating and Cooling Company respectively. 9 Details of the calculations of economic
benefits are presented in Box 5.
Box 5: Equations to calculate Monetary Benefits (Cost Savings and Potential Income)
PES = [(SEC BM - SEC B )* FA b ]
ElSa B = [(PES*Sh E )/9.76]
HCSa B = [(PES*Sh HC )/1.36]
CS B = [(ElSa B *18y)+( HCSa B *5.6y)] / 1.000.000
TCO2 red = [(CO2 BM – CO2 B )*FA b ] / 1.000
PI B = (TCO2 red *2000y) / 1.000.000
PES: Primary energy saving that is total (primary) energy saving in the building per annum
(MJ/yr)
SEC BM : Benchmark for specific energy consumption (MJ/m 2 /yr)
SEC B : Specific energy consumption of the building (MJ/m 2 /yr)
FA b : Floor area of the building (m 2 )
ElSa B : Total annual electricity saving in the building (kWh/yr)
Sh E : Share of electricity consumption in building’s total energy consumption (%)
HCSa B : Total annual heating and cooling energy saving in the building (MJ/yr)
Sh HC : Share of heating and cooling energy consumption in building’s total energy
consumption (%)
CS B : Cost savings of the building (million yen)
TCO2 red : Total CO 2 reduction based on energy savings of the building (tonnes/yr)
CO2 BM : Benchmark for CO 2 emissions per square metre (kg/m 2 /yr)
CO2 B : Total annual CO 2 emissions per square metre of the building (kg/m 2 /yr)
9 (1) For unit price of electricity, please see the report titled “Guidebook on Energy Conservation for Buildings: 2010/2011”
by the Energy Conservation Center of Japan (ECCJ) from the following link: http://www.asiaeeccol.eccj.or.jp/brochure/pdf/guidebook_for_buildings_2010-2011.pdf
(2) For unit price of heating and cooling energy, please see the report titled “MinatoMirai 21 District Heating and Cooling”
prepared by the Minato Mirai 21 District Heating and Cooling Company. Same information can be found on the company’s
website from the following link: http://www.mm21dhc.co.jp/english/faq/index.php#qes6
18

PI B : Potential income based on trading of reduced carbon emissions (million yen)
9.76 is the primary energy conversion factor for electricity
1.36 is the primary energy conversion factor for heated and cold water
18y is the unit price of electricity (yen)
5.6y is the unit price of heating and cooling energy (y)
2000y is the price of 1000kg of CO 2 reduction in Japan (y)
6. Case Studies
6.1. Green and Low-Carbon Technologies in Case Study Buildings
There are two basic design paradigms of features and technologies that are applied to
buildings in order to make them green and eco-friendly. The first is based on the concept of
“passive design” in which natural elements such as air-flow and sunlight are used to provide
a comfortable indoor environment while reducing energy demand for space heating, cooling,
ventilation and artificial lighting (Rode et al., 2011). The second, namely the “active
approach”, is based on the use of newer technology and state-of-the-art systems to improve
energy efficiency and reduce energy demand and resource consumption in buildings (Rode et
al., 2011). These technologies and systems generally include solar PV panels, heat pump
systems, wind turbines, Low-E double-glazing windows, light sensors, LED lights,
computerized energy management systems, etc. The mainstream approach in the Japanese
building sector is to apply both paradigms to construction of new buildings and also to
retrofitting schemes. In almost all of the case study buildings, application of both paradigms
was observed, although to varying degrees.
6.1.1 Passive Design Strategies
Among the most effective and recent passive design strategies in the Japanese building sector
is the Eco-Void System, which is mainly an empty channel in the middle of the building
designed to bring more natural light into the building. Two of the case-study buildings,
namely Building A and B, had such a void system combined with sun-tracking sensors and
mirrors on the rooftop. Building B had an advanced eco-void system, which allows natural
sunlight to enter throughout the building from the top floor all the way to the third floor
(which is a distance that covers about 80 metres). The eco-void works so that there is a
primary mirror which is pre-programmed to change angles to catch the movement of the sun
throughout the day. The primary mirror directs the sunlight to a secondary mirror which
sends sunlight down the void. Throughout the void, there are long panels that disperse the
light coming in through the void, giving each floor natural day light. Depending on the
amount of sunlight coming in, the automatic lighting combined with daylight sensors change
19

intensity, so that it minimizes electricity consumption on days when sunlight is sufficient to
light up each floor. The eco-void in Building B also served as a ventilation system where
used air is disposed by vents out into the void, and by using temperature and pressure
differences, the used air is pushed out into the open spontaneously without use of motors.
According to calculations made by building owners and managers, an electricity saving of 15
per cent was achieved from the eco-void in Building B.
Buildings generally have special façade designs to bring more sunlight into the building. The
vertical pillars are designed and constructed accordingly not to block the diffusion of natural
light from openings to the indoor environment. Building D had such specially designed
pillars. The vertical pillars on the façade were designed in the shape of a triangle rather than
rectangle in order to get more sunlight through the windows. The triangular pillars were
found to be three times more effective than the rectangular ones in terms of bringing in
natural lighting indoors per square metre.
Use of external louvres is among the most common passive design strategies applied to green
buildings in Japan. Two of the case study buildings had such louvres mainly to avoid the
direct entrance of solar radiation into indoor environment. Building A had a special louvre
system on the façade that was designed by taking into consideration the sun’s yearly
movement and seasonal positions on the particular location the building occupies. The louvre
system helps reflect sunlight into the building in appropriate ways to prevent the building
from overheating during summertime. This system was designed and implemented to reduce
the need for indoor cooling and thus reduce energy consumption during warm periods.
Similarly, Building C had an external louvre system that not only aims to block direct
sunlight to enhance air conditioning performance but also encourages the diffused reflection
of natural light towards the ceiling surface to increase illumination efficiency. This is also
combined with daylight sensors on ceilings that control the lighting equipment on the
perimeter zone.
Rooftop greenery is another common feature of green buildings. Such green spaces are also
being applied to existing buildings, as part of retrofitting schemes. For instance, a rooftop
garden with a size of 1,000 m 2 was added to Building E during the recent retrofitting of the
building. The main motivation behind plantation of greenery on rooftops is to help cool down
the building by reducing the urban heat island (UHI) effect on the building. In addition,
rooftop gardens, to a certain extent, are known to help carbon sequestration. Along with
rooftop gardens, most of the buildings have greenery on their sites. A certain amount of the
site area is generally designated to greenery and organized as gardens including permeable
surfaces and trees. For instance, 51 per cent of the entire site area of Building B is dedicated
to trees, grass, and greenery in order to address UHI effect.
20

Another common strategy to mitigate UHI effect and cool down buildings naturally is the
supply of water retaining pavements on rooftops and ground floors. Some of the case study
buildings had such pavements to keep buildings cooler by means of evaporative cooling
during summers. In a similar direction, one of the case study buildings had certain parts of its
rooftop painted with sunlight reflecting paint in order to reduce the amount of sunlight
absorbed, and thereby mitigate UHI effect.
6.1.2 Active Design Strategies
Among the most common strategies for energy efficiency in buildings in Japan is the
connection to District Heating and Cooling System (DHCS). DHCSs provide associated
buildings with steam for indoor heating and cold water for indoor cooling as well as hot water
supply. Due to collective generation of steam and cooling water via centralized boiler and
chiller facilities, DHCSs result in improved operating efficiency. Compared to stand alone
systems, DHCSs provide its users with significant energy savings as well as other side
benefits, such as space and personnel savings, as DHCS users do not need to allocate space
for boilers and chillers and hire technical staff to take care of them. All case study buildings
examined in this research had DHCS connections in order to obtain steam and cold water for
indoor heating and cooling.
In a similar direction as DHCS, there is also a tendency among building owners and
managers in Japan towards the use of Building Energy Management Systems (BEMS). BEMS
are standardized energy management systems that use computerized information processes to
efficiently and effectively reduce energy consumption in a building without compromising
the comfort and safety of its internal environment (Nakagami, 2011). Building B, one of the
case study buildings, had its own BEMS, which evaluates the efficiency of the energy
management in the building. The system also suggests and promotes measures to reduce
energy consumption based on evaluation results.
LED lights are also a common strategy in green and retrofitted buildings in order to reduce
energy use for indoor lighting. They are mostly used to illuminate common spaces in office
and commercial buildings. The performance of LED lights is superior to normal lighting
appliances, as they are long-lasting and provide the same amount of illumination with lower
energy use.
It is common to use low-E double-glazed windows both in green buildings and retrofitted
buildings in Japan. Low-E double-glazed windows are mainly used for improving the thermal
insulation efficiency of a building, as double-glazed glass panes sandwich air for insulation
(Nakagami, 2011). The recent improvement in this technology is the insertion of a special
metallic film coating behind the glass pane to enhance insulation performance (Nakagami,
2011). In this sense, this type of glass system allows sunlight into the building but insulates
21

excess heat by keeping it in between the two glass panes. In most of the case study buildings,
such window systems were implemented to reduce the energy need for air conditioning.
Airflow window systems are becoming popular in the Japanese building sector. Such systems
aim to improve solar radiation insulation and thermal insulation efficiency (Nakagami, 2011).
Building C had such a system to support Low-E double glazing and airtight blinds. The
“simple airflow system” applied to the windows is designed to generate an ascending air
current to discharge the heat that comes in from window panes during summers and also to
generate a descending air current to suck in the cold drafts that strike window panes through
air discharge slits at the bottom of the panes during winters. This system is said to efficiently
discharge the cold air that comes in from windows.
Along with energy efficiency, generation and use of renewable energy are also important
strategies applied to green buildings. In this respect, most of the green buildings visited
during this research had solar PV panels on their rooftops. However, electricity generation
capacities of these panels were very limited, ranging from 10KW to 40KW and the electricity
generated by them covered only a very marginal part of total energy supply in the buildings.
The main reason to keep solar PV panels at a very symbolic level is the initial cost of
investment. The existing system in Building D with a total capacity of 10KW cost around
JPY30 million. There are no subsidies and/or incentives by governments to encourage
building owners to use higher capacity PV panels. The second reason is the difficulty of
storing and selling electricity generated on-site by energy generation systems. The batteries
that are used to store excess electricity are expensive and there is no system that enables
buildings to sell their electricity to the grid. Building A was an exception in this regard, as the
building is equipped with batteries to store the electricity generated by solar PV panels. This
is mainly due to the company’s commercial interests in improving the technology of these
batteries. Among all buildings examined Building A had the highest capacity solar PV system
(40KW), which could generate 43.800 kWh of electricity per annum.
In almost all of the buildings examined, either green or non-green, there were systems to
increase water savings and recycling. Rainwater harvesting and recycling systems are the
most common systems. Usually on rooftops of buildings, there are tanks in which rainwater is
harvested. The harvested water is generally reused to flush water in toilets and as irrigation
water for rooftop greenery and green spaces around the buildings. In addition, there are also
some other water-saving technologies especially used in toilets, which are the main source of
water consumption in office and commercial buildings.
6.2 Environmental and Economic Benefits of Case Study Buildings
The results of the case study analysis are presented in Table 2. The results indicate that green
buildings can yield significant environmental and economic benefits. The case study building
22

with the best performance in this research (Building A) had a specific energy consumption of
1,537 MJ/m 2 /yr, which is almost 40 per cent less than the average specific energy
consumption in tenant-occupied office buildings in Tokyo in 2005. Likewise, annual CO 2
emissions per square metre in this building was calculated as 62 kilograms, 42 per cent less
than the average of tenant-occupied office buildings in Tokyo in 2005. Based on the
reductions in energy consumption and CO 2 emissions, the case study building with the best
performance was found to yield an annual economic benefit of approximately JPY 240
million to its occupants. Last but not least, it was also observed that 26,000 m 3 water was
saved annually in this building, owing to special water recovery and recycling techniques
used in the building.
Table 2: Results of the Analysis of the Case Study Buildings
Building
Name
Building
A
Building
B
Building
C
Building
F
Building
D
Building
E
Building
G
Average
Values
Rank
1
2
3
4
5
Energy Consumption
Primary
Energy
Use
141,379
GJ/yr
161,615
GJ/yr
217,595
GJ/yr
161,008
GJ/yr
182,542
GJ/yr
6 No Data
7
Av.
79,877
GJ/yr
157,336
GJ/yr
Specific
Energy
Use
1,537
MJ/m 2 /
yr
1,697
MJ/m 2 /
yr
1,900
MJ/m 2 /
yr
1,949
MJ/m 2 /
yr
2,025
MJ/m 2 /
yr
No
Data
3,153
MJ/m 2 /
yr
2,043
MJ/m 2 /
yr
Reduction
Rate
39.0%
32.6%
24.6%
22.6%
19.6%
No
Data
No
Reduction
19.0%
CO 2
Emissions
Total
5,680
tonnes/yr
6,478
tonnes/yr
8,730
tonnes/yr
6,448
tonnes/yr
7,289
tonnes/yr
No Data
3,204
tonnes/yr
6,305
tonnes/yr
CO 2 Emissions
CO 2
Emissions
Specific
61.7
kg/m 2 /yr
68.0
kg/m 2 /yr
76.2
kg/m 2 /yr
78.1
kg/m 2 /yr
80.9
kg/m 2 /yr
103.1
kg/m 2 /yr
126.5
kg/m 2 /yr
85.0
kg/m 2 /yr
Reduction
Rate
42.3%
Water
Savings
26,277
m 3 /yr
36.4% Marginal
28.8%
27.0%
24.4%
3.6%
No
Reduction
20.5%
No
Data
10,659
m 3 /yr
No
Data
No
Data
No
Data
18,468
m 3 /yr
Economic
Benefits
Cost
Savings
233
million
yen
195.4
million
yen
179.1
million
yen
115.8
million
yen
105
million
yen
No
Data
No
Saving
168
million
yen
Potential
Income
8.3
million
yen
7.4
million
yen
7.1
million
yen
4.8
million
yen
4.7
million
yen
3.1
million
yen
No
Income
5.9
million
yen
23

When average values of all case study buildings were considered (last row of Table 2),
significant environmental and economic benefits were also observed. The average specific
energy consumption in all case study buildings analysed was 2,043 MJ/m 2 /yr, which
corresponds to a 19 per cent reduction compared to the benchmark level. The associated CO 2
emissions of average annual energy consumption in case study buildings were calculated as
85 kilograms, 20 per cent less than the benchmark (Table 2). Finally, the average economic
benefit yielded by all case study buildings was calculated as JPY 175 million per year along
with water savings of almost 19,000 m 3 /year.
Among the case study buildings examined, best performances mostly belonged to green
buildings, especially the ones that were already in use. The top two performances belonged to
Building A and Building B, which were designed and constructed as green buildings and
have been in use for some years. They were followed by another green building, Building C,
which has started being used very recently. On the other hand, existing retrofitted buildings
may perform as well as green buildings mostly due to wider implementation of District
Heating and Cooling Systems (DHCs) and Energy Service Companies (ESCOs) in Japan.
Building F was a good example of this, as specific energy consumption and associated CO 2
emissions per square metre in this building were respectively 23 per cent and 27 per cent
lower than those of Tokyo tenant-occupied office buildings in 2005.
Actual performances of green buildings are better than their planned performances mainly
because of good energy management during the operation phase. Efficient use of energy in
large commercial buildings 10 has for some time been a policy priority and a significant
concern for national and local governments as well as building owners and managers in Japan.
The energy shortage caused by the accident in Fukushima Nuclear Power Plant after the
Tohoku Earthquake and Tsunami in 2011 has increased such concerns over energy
consumption in the building sector. Owners and managers of large commercial buildings
within the supply area of Tokyo and Tohoku power companies were asked by national and
local governments to reduce energy consumption in their buildings by 15 per cent. 11 In line
with this request, several measures and strategies were introduced to cut down energy use in
large commercial buildings in the TMA. For instance, managers of Building A have
introduced three particular strategies in this respect: lunch-time darkening, turning off the
lights at 8pm and 9pm every night so as to darken the offices with no staff and shutting down
heating and cooling system at 6pm every day. The first two strategies were calculated to
reduce electricity consumption for lighting by 17.4 per cent. In sum, such measures and
10
There may be different definitions of large commercial buildings depending on contextual factors. In this research, they
refer to the definitions used in related legal and policy documents of the Japanese government. As per this definition, a large
commercial building has an energy consumption of more than 1,500 kiloliters of crude oil equivalent per year.
11 Based on the personal communication with the managers of the case study buildings during the field work.
24

strategies have been effective in improving energy efficiency of green buildings, leading to
better actual performances than planned.
Another interesting finding was that owner-occupied buildings had better performance than
tenant-occupied ones. Although there was only one owner-occupied building among the case
study buildings, better performance of owner-occupied buildings was also verified by the
interviewees during the field work. Considering the monetary gains from energy and
resources savings, building owners do not hesitate to invest in green technologies in owneroccupied
buildings. Monetary benefits constitute significant returns on their investments.
However, in tenant-occupied buildings, building owners tend not to invest much in such
technologies, as likely monetary gains will be obtained by tenants.
Performance of the case study buildings in terms of reduced energy and resource
consumption was mainly based on efficiency improvements. Cleaner and renewable energy
sources were not in place yet. In all case study buildings, the share of renewable energy in
total energy supply was either non-existent or very marginal. However, increasing attention
on use of geothermal energy and ground source heat pumps in the building sector may be an
opportunity for future initiatives in Japan. Despite the limited progress in use of renewable
energy in the building sector, performances of green and retrofitted buildings in major
Japanese cities are superior to their international counterparts. This statement was also
verified by the findings of the case study in this research. For instance, in Jiang and Tovey’s
research (2010), the average CO 2 emissions in case study buildings are 178 kg CO 2 /m 2 /year
in Beijing and 119 kg CO 2 /m 2 /year in Shanghai, whereas the average CO 2 emissions in case
study buildings in this research was 85 kg CO 2 /m 2 /year. Likewise, CO 2 emissions reduction
in the Ocean Financial Center, the prominent new green building in Singapore’s CBD and the
winner of the Green Mark Platinum Award by Singapore's Building and Construction
Authority, was measured as 4,500 tonnes per year, whereas the average of the case study
buildings in this research was calculated as 6,305 tonnes per year.
7. Challenges and Opportunities to Implement Green Buildings on a Wider Scale
The discussion in this section sheds light on the challenges and opportunities for wider and
better implementation of green buildings.
7.1 Challenges/Barriers
Cost is the main barrier to promote green buildings in Japan at present. Green technologies
and measures used in green buildings result in high initial investment costs. Besides, there are
not many incentives or much support from the Japanese government for real estate and
construction companies in this respect. The major benefit to building owners is thus cost-
25

savings from reduced energy consumption and trading opportunity in case of emission
reductions. Therefore, companies (those willing to construct a green building or retrofit their
buildings) have to bear the upfront costs by themselves, and wait for the payback period to
get returns on their investments. As per the information given by some of the interviewees,
the payback period of green technologies in Japan is around 10 years, which may be too long
for companies with limited resources. For this reason, main players in the green building
market in Japan are now big companies with sufficient resources. At present, green buildings
in the TMA are either the HQ buildings of big companies or leasehold buildings of big
construction and real estate firms.
As an outcome of the previously mentioned situation, owner-occupied buildings seem to have
advantages over leasehold buildings, as concerns over investment costs are higher in case of
the latter. For this reason, green buildings constructed for rental purposes are low in numbers.
However, there are big construction companies investing in green building construction for
rental purposes in order to develop technologies and find innovative solutions that they can
export later.
Fragmentation of legal and institutional frameworks is another significant problem. Several
policy and legal frameworks have been developed by different public bodies in Japan with
regard to green and retrofitted buildings, and this makes the entire system too complicated
and difficult to follow and comply with. Companies with limited financial and human
resources have difficulties in this respect. Besides, there are various public authorities
involved in the system and in some cases responsibilities are divided among them in
inefficient ways. For instance, responsibilities regarding energy consumption in buildings are
divided between MLIT and METI based on stages of construction. It is MLIT’s responsibility
to deal with energy-related issues before and during the construction of buildings and then
METI becomes responsible for the same issues when the construction is over and the building
is put in use. Such institutional disharmony can hinder the achievement of energy efficiency
goals set by policy and legal frameworks. 12
The complicated nature of relevant policy frameworks hinders the promotion of green
building construction in Japanese cities. Policy frameworks related to construction and
building energy and environmental efficiency (BEE), such as Cap and Trade Program,
CASBEE, Environmental Impact Assessment are known to be complicated and timeconsuming.
A certain level of in-house expertise is required to follow and comply with these
frameworks. Therefore, companies with limited resources are discouraged to implement
green technologies in their new building construction investments. Besides, most of these
initiatives are on a voluntary basis. Regulatory and mandatory mechanisms and programmes
12 Based on the personal communication with the managers of the case study buildings during the field work.
26

are very recent and they stem from policy frameworks that are not specifically for building
construction like Energy Savings Law and Environmental Ordinances. There are no
mandatory regulations, standards or guidelines regarding energy and environmental
efficiency in the Building Act of Japan.
Despite the current progress, awareness of building energy and environmental efficiency
among basic consumers like house buyers and tenants in office and commercial buildings
appears to be low in Japan. Consumers do not pay sufficient attention to energy-related and
environmental aspects when buying or renting property and thus developers are not urged to
push the green building agenda forward.
Related to the previous challenge, lack of information is another significant barrier. Even if
consumers pay attention to building energy and environmental efficiency aspects, they do not
have access to sufficient information about energy and environmental performance of
buildings. Labeling systems that have recently been introduced are promising but they are
new and not yet prevalent.
7.2 Opportunities/Strengths
Political will and commitment can be considered as one of the major success factors in
promotion of green buildings in Japan. There is a general consensus among public and
private agencies to tackle the climate problem via initiatives in most related and crucial
sectors of climate policy. The building sector is one of these sectors, where various initiatives
and policies that address the climate problem have been introduced by public authorities at
both national and local levels. Public authorities and officials are well-aware of the problem
and have significant motivation for further improvements.
Corporate Social Responsibility (CSR) is another opportunity in this respect. It is common
among private companies to undertake actions to address environmental problems including
climate change. Such actions are seen and have already been accepted as part of their
corporate social responsibility. All building owners and managers interviewed confirmed that
good company images and improving their CSR were the main motivations behind their
actions with respect to green building construction.
Competition in the market seems to be effective in promoting green and low-carbon buildings.
As new green buildings are coming to the market with superior design and technologies, this
motivates construction and real estate companies to construct green buildings or retrofit their
buildings in order to attract tenants.
Japan has five big construction companies that have high institutional and innovative capacity.
These companies tend to develop and sell new and improved green technologies and
therefore are willing to invest in green building construction.
27

8. Conclusion and Policy Implications
The concept of green buildings, which is based on the application of sustainability principles
to building design, construction and management processes, can be an effective strategy to
address adverse environmental impacts. In particular, construction of green buildings can
help mitigate carbon emissions by reducing energy demand of buildings and also by
increasing the efficiency of energy and resource use in buildings. However, realizing the
potential of green buildings is not easy. Although there has been some progress in the
development of the green buildings concept, implementation is still in its infancy. In both
developed and developing countries, the greening of buildings has not taken place on a wider
scale, due to some significant challenges.
This research shows the extent of environmental and economic benefits that green buildings
could generate as well as opportunities for and barriers to push the green buildings agenda
forward in Japan. Based on the findings of this research, the following points are drawn as
main policy implications and recommendations to eliminate the barriers and utilize the
opportunities.
a) Financial support and incentive mechanisms should be developed and introduced by
the public sector in order to assist companies during the payback period of their green
investments. Particularly, long-term loans that will be paid back by cost-savings could
be provided to companies.
b) Revisions should be made to policy and legal frameworks so as to make them less
complicated, simple, straightforward and well-integrated.
c) Support mechanisms of various sorts should be introduced for companies with limited
human and financial resources.
d) Building owners are in a better position compared to tenants, therefore better
communication between owners and tenants could help tenants become more aware
and knowledgeable about legal frameworks that enable them to achieve energy and
environmental efficiency. Governments should develop mechanisms to increase
owner and tenant communication and collaboration.
e) In a similar direction with the previous point, mechanisms are needed to raise
awareness of and provide more information to basic consumers within the building
sector.
28

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