Download CTBUH Technical Paper - Council on Tall Buildings and Urban Habitat

CTBUH
Technical Paper
http://technicalpapers.ctbuh.org
Subject:
Sustainability/Green/Energy
Paper Title:
Environmental Performance of the TTDI
Author(s):
Suraksha Bhatla
Joana Gonçalves 1
Affiliation(s):
1
Publication Date:
2012
Original Publication:
CTBUH Journal 2012 Issue II
Paper Type:
1. Book chapter/Part chapter
2. Journal paper
3. Conference proceeding
4. Unpublished conference paper
5. Magazine article
6. Unpublished
Universidade de São Paulo
© Council on Tall Buildings and Urban Habitat/Author(s)
CTBUH Journal
International Journal on Tall Buildings and Urban Habitat
Tall buildings: design, construction and operation | 2012 Issue II
Capital Gate, Abu Dhabi
Securing Iconic Structures
Environmental Performance of the TTDI
Developing Rotterdam’s Skyline
Talking Tall: The Skyscraper Index
Debating Tall: Is UNESCO Going Too Far?
Tall Buildings in Numbers: Occupiable
Telecommunication & Observation Towers
Inside
News and Events
02 This Issue
Steve Watts, CTBUH Trustee
04 CTBUH Latest
Antony Wood,
CTBUH Executive Director
05 Debating Tall: Is UNESCO
Going Too Far?
06 Global News
Highlights from the CTBUH
global news archive
Case Study
CTBUH
12
Case Study: Capital Gate, Abu Dhabi
46 Helsinki: Developing a Finnish
Vernacular for the High-rise?
Antony Wood
Jeff Schofield
Author
Jeff Schofield, Associate
RMJM
Floor 27, Monarch Office Tower
PO Box 6126
Dubai
UAE
t: +971 4 702 7626
f: +971 4 329 6444
e: [email protected]
www.rmjm.com
Jeff Schofield
Since moving to RMJM Dubai in 2005, Jeff Schofield
has lent his design expertise to a variety of large scale
building developments, including mixed use,
hospitality and high-rise projects.
48 CTBUH Young Professionals
Committee Launches
Ambitious Agenda
Kevin Brass
49 CTBUH Research
Development Initiative:
An Update
Payam Bahrami
51 CTBUH on the Road
CTBUH events around the
world.
As an Associate at RMJM, Jeff leads the effort in
providing sustainable solutions to all design projects in
the office. He has developed a holistic approach to
design that integrates sustainability, structure and
architectural expression with the built form, in order to
provide meaningful solutions for high-quality building
designs. Jeff seeks to design in a contemporary yet
contextual manner, to create modern sustainable
buildings using the latest technology.
g his
Jeff currentlyy lives and works in Dubai. He began
career in New York City and pursued his professional
practice for more than 15 years in Paris, France. Jeff has
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18
24
32
Securing Iconic Structures
Sean Ahrens & Stephen Yas
The Environmental
Performance of the TTDI
Suraksha Bhatla & Joanna
Gonçalves
18
Developing Rotterdam’s
Skyline
Frank van der Hoeven &
Steffen Nijhuis
Sean Ahrens
Stephen Yas
Aon Fire Protection Engineering
Security Division
1000 Milwaukee Avenue, 5th floor
Glenview, IL 60025
United States
51 Diary
Upcoming tall building events
t: +1 847 461 9359
f: +1 847 953 7793
[email protected]
www.aonsecurity.com
Stephen Yas, Design Principal
MulvannyG2 (Shanghai) Architecture
Ciro’s Plaza Suite 1905
388 Nanjing Xi Road
Shanghai 200003
China
Features
38 Tall Buildings in Numbers
A Look at Occupiable
Telecommunication &
Observation Towers
40 Design Research
University of Nottingham
42 Talking Tall: The Skyscraper
Index
Andrew Lawrence
52 Reviews
Review of new books in the
CTBUH Library
Sean A. Ahrens
Sean leads the security consulting practice at Aon FPE
with over 19 years of experience, a majority of which
has been in a security consulting function. He has been
responsible for providing security threat and risk
analysis, contingency planning, loss prevention, and
force protection design and planning. Sean has
provided design and construction administration for
government, public, and private entities that
encompass telecommunications, security, surveillance,
and access control systems. He is well versed in the
various trade and local authority issues impacting
projects, and has specialized professional competence
in security, access control systems, and force
protection systems.
Stephen Yas
Stephen has over 35 years experience working
internationally. He specializes in architecture, urban
design and interior design for large mixed-use
projects. As design principal in the Shanghai office of
MulvannyG2 Architecture, he is the design leader in
china for the firm. Prior to MulvannyG2, Stephen leads
his own firm in Chicago for 22 years. Prior to that he
was a senior designer at SOM Chicago and Lohan
Associates, as well as working in England and the
Middle East.
52 CTBUH in the Media
Selection of media coverage
53 What’s on the CTBUH Web?
Featuring new content now
available on the website
The Concept
In 2005, the Abu Dhabi National Exhibitions
Company (ADNEC) was created to drive
forward the development of Abu Dhabi’s
events sector. Plans were created with RMJM
to build a state-of-the-art exhibition centre
which would be the largest in the Gulf region
and provide world class facilities for live events
to flourish in Abu Dhabi.
It was strongly felt that the entire
development required a signature tower, a
cutting-edge structure with a futuristic design,
• The vertical and horizontal cross-sections of
the tower are all unique
First of its Kind
There are several innovations within the
project’s design, including the dramatic
18-degree westward lean, which has earned it
the title of “world’s furthest leaning manmade tower” from the Guinness book of world
records (see Figure 1). It is also the first
building in the world to use a pre-cambered
core with a built-in lean of 350
millimeters that has been
engineered to straighten with
the addition of the upper
floors. And it is the first building
in the world to use vertical
post-tensioning of the core to
counter movement and
support stresses created by
the building’s overhang.
aesthetic splendor and technical excellence to
celebrate human achievement and reflect the
dynamism of Abu Dhabi.
Capital Gate is the result.
The tower’s curvaceous shape draws strongly
on the sea and desert – two elements that
have great resonance in Abu Dhabi. The
building’s form is meant to represent a
swirling spiral of sand, while the curved
canopy, known as the “splash,” which runs over
the adjoining grandstand and rises on one
side of the building, creates a wave-like effect,
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“In sophisticated urban planned environments,
security should be subtle, but allow for the
potential for heightened threats. The key is to
find a suitable balance between security and
preserving the designer’s vision. A security
program for any structure should employ a
variety of controls to deter, delay, detect, deny
and respond to threats, as well as mischievous
or potential accidental acts.”
This paper emphasizes the importance of integrating security programming into building
design, allowing for different uses and threat levels for the life of the building. Security
strategies will be evaluated that can be applied to any building, as well as review procedures
to address concerns early in the design process, especially in politically and economically
charged international environments. General concepts and approaches to building security
will be examined, demonstrating the benefit of collaboration between architects and security
professionals at an early stage to meet the project’s goals without detracting from the
planner’s vision for the project.
The “Fortress”
To the untrained eye, this graphic (see Figure
1) may appear “fortress” like. However, in its
most basic format, the diagram describes the
security program for building at any security
level. Early dialogue between security
professionals and the designer can limit the
fortress or bunker aesthetic by careful
placement of technical security, including
cameras, setbacks, gates, fencing and spatial
provisions for security staffing.
In many cases, consideration is not given to
the potential for a future modification to the
building, such as the addition of a casino,
parking garage, skate park or theater, which
may increase the potential for malevolent
acts. The addition of new tenants, such as a
dignitary or VIP, may require a change in the
security status not considered in the original
design process. The modification of the
physical and architectural security component
is the most important, most expensive and,
therefore, most difficult to modify post-design.
Done early in the design process there is
significant indirect and direct return on
investment that can be achieved by preplanning.
When planning a facility, design professionals
need to think outside-the-box. Although fear
of terrorism typically drives the mindset for
iconic building security, there are other more
likely threats, including workplace violence,
domestic spill over issues, intellectual theft,
property theft and other malicious acts
against persons or property that can affect the
building and its occupants. Unforeseen
dangers can create significant security
challenges for building owners post-design
and may detract from the marketing, image
and status of the project. Planning for a single
threat may not be effective and may miss
potential threats in the future. The best
approach is to create generalized controls
designed to address a broad range of threats.
Unlike other building elements, there are no
standards for the provision of security based
on building occupancy. As a result, the
evaluation and development of security
controls is purely based on a quantitative risk
and consequence analysis which evaluates all
aspects of the proposed building, not simply
such critical assets as electrical and
telecommunications systems. Conducting a
risk and consequence analysis will assist the
18 | Securing Iconic Structures
32
• Four hundred and ninety foundation piles
were driven 20 to 30 meters underground
to support the structure and counter
stresses. The piles, which were initially in
compression during construction to
support the lower floors of the building, are
now in tension as the stresses caused by
the overhang have been applied.
The construction also
adopted a variety of
leading-edge approaches to
create the desired result,
including:
• Asymmetric shape – no two rooms are the
same (see Figure 2); every single pane of
the 12,500 panes of glass on the façade is a
different size although each pane is
triangular
• Floor plates change shape and orientation
to create the distinctive “overhang” moving
from “curved triangular” to “curved
rectangular,” while increasing in overall size
and migrating from east to west as they
progress up the tower
• Capital Gate is one of few buildings in the
world that use a diagrid structure; it also
features two diagrid systems, an external
diagrid defining the tower’s shape and an
internal diagrid linked to the central core by
eight unique pin jointed structural
members.
• All 8,250 steel diagrid members are
different thicknesses, length and
orientation 
Figure 2. Typical hotel floor plan © ADNEC
CTBUH Journal | 2011 Issue II
Capital Gate, Abu Dhabi | 13
Securing Iconic Structures
Sean A. Ahrens, Practice Leader/Manager
53 Comment
Feedback on the past journal
issue
By integrating with the National Day
Grandstand – one of Abu Dhabi’s most
historic structures – Capital Gate underscores
the bond between the traditional and
modern that is characteristic of Abu Dhabi’s
developmental approach.
Figure 1. Typical section © ADNEC
t + 86 21 6032 0100
f + 86 21 6217 8525
e: [email protected]
www.mulvannyg2.com
Research
reflecting the building’s proximity to the water
and the city’s sea-faring heritage.
Throughout history, a strong link has existed between iconic architecture and exhibitions.
One of the best known examples is Paris’ Eiffel Tower, which was built as a visual symbol of the
Exposition Universelle, World’s Fair of 1889. More recently cities like Seville have used
powerful and innovative architecture as a way to highlight the cultural significance of their
exhibitions.
12
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12 Capital Gate, Abu Dhabi
Jeff Schofield
“From the beginning of concept design, the
architects and engineers integrated many
passive and active sustainable systems into
Capital Gate, its most visible sustainable
feature is the “splash,” which twists around the
building towards the south to shield itself as
much as possible from direct sunlight.”
CTBUH Journal | 2011 Issue II
designer with understanding the exposure to
threats. For example, a building near a
proposed or existing mall will make criminal
incidents more likely. In similar fashion,
integrating a train or metro into a large
high-rise project could increase exposure to
chemical or explosive attacks, while the
creation of a building near a government
facility or embassy may escalate the tertiary
terrorism risk.
The type of building and its tenants may also
affect risk rating, which can change over time.
Understanding the risks early in the process
will assist organizations in making decisions.
The planner should ensure that the security
analysis provides specific guidance and
recommendations on vehicular access,
security placement of cameras, access control
and the overall security compartmentalization
program.
From a security perspective, designers need
to think about the “what-ifs.” They need to
have a vision. That does not necessarily mean
implementing controls from day one, but
designing provisions into the architecture so
security controls can be easily and quickly
adopted in the future if higher threat
scenarios arise.
The downside of shortsighted preplanning is
evident in the airports built 20 years ago. The
functions and usage of airports have changed
dramatically. The free flowing public
environment of yesterday is now a series of
mazes and security compartmentalization
which could have been avoided, if only
designers had taken a more open-minded
approach during the design process.
Preparing for the Future
To prepare for tomorrow’s uncertainties,
today’s international planners should start by
evaluating the site and potential setbacks and
standoff distances from the façade of the
building. Even with constricted site layouts,
there are opportunities that can be explored.
Setback can be achieved through a number
of programming elements. To increase the
affect of clear space, the perception of setback
can be somewhat masked through
architectural programming, such as the
creation of multi-tiered planting areas, water
features, structures and natural boulders. The
proposed US Embassy in London employs an
enveloped glass façade and a water feature to
support security. The water feature provides a
visual element to the project, but it also
creates a defined perimeter and clear zone.
When developing building placement,
roadways should be carefully evaluated.
Centralized or limited roadway access is
preferred, while incorporating standards and
requirements for emergency access. In some
cases, emergency access roadways will need
to be secured and may create a conflict with
first responders. Proper signage and clear
access routes can limit frustration by people
who are not familiar with the site, which could
be a key to minimizing negative interactions
with security. Site confusion can lead to anger.
Roadways are integral to the project, but
simple and cost effective techniques, such as
using a serpentine access road, can create
elegant and effective solutions to reduce the
potential for a vehicle to approach a building
at high speed.
Counter terrorism and counter surveillance
techniques are extremely beneficial to
identifying an aggressor. For this reason,
building layout, whenever applicable, should
afford natural sight lines to allow the
detection of an intruder. As a result,
landscaping is extremely important. Trees and
other foliage that can obscure sight lines
should be discouraged. Lighting, the number
one deterrent to crime, may become
obscured by growing tree canopies. As a
result, lighting plans and photometric should
take into account tree growth over the life of
the tree and the effect on the light
distribution. By doing this more effective light
placement can be identified.
Hotels will often employ a porte cochere,
which can expand setback from the primary
structure while providing continuity in
architecture and limit the perception of
distance from the entry to the building.
Setback is more than maintaining vehicle
proximity, setback increases natural lines of
sight as well as the area that must be
traversed prior to accessing a facility, while
supporting the potential for early detection of
an aggressor. Designs should limit
components that may be used by aggressors
for criminal acts. Loose rocks of substantial
size could be used to break windows to gain
entry to a building or be picked up as a
makeshift weapon in an ambush scenario. If
rocks are integral to design, they should be
kept small or be large enough that they can’t
be easily picked up.
The Worst Case Scenario
When designing setback and site placement,
consideration should be equally afforded to
the planning for emergency vehicles and
muster points for evacuating tenants. Muster
points need to account for the expected mass
of people and should be as far away from 
Figure 1. The “fortress” © Aon
CTBUH Journal | 2011 Issue II
Securing Iconic Structures | 19
Developing Rotterdam’s Skyline
Frank van der Hoeven
Steffen Nijhuis
Authors
Frank van der Hoeven, Associate Professor
Steffen Nijhuis, Assistant Professor
Delft University of Technology
Faculty of Architecture
Julianalaan 134
2628 BL Delft
The Netherlands
t: +31 15 278 9805
e: [email protected]
e: [email protected]
www.graduateschool.abe.tudelft.nl
Frank van der Hoeven
Prof. van der Hoeven is an associate professor of urban
design at the Faculty of Architecture at the Delft
University of Technology, the Netherlands. He
conducted his PhD research in the field of
underground space technology and multifunctional
and intensive land-use. The core of his work deals with
urban design issues related to mixed-use
development: transit-oriented development, urban
greenhouse horticulture, the use of underground
space, high-rise urban areas and climate change.
Currently he combines his associate professorship in
urban design with the position of Director of Research
of the Faculty of Architecture.
54 Meet the CTBUH
Kevin Brass
Steffen Nijhuis
Prof. Nijhuis is an assistant professor of landscape
architecture at Delft University of Technology (the
Netherlands). His PhD research, entitled “Landscape
Architecture and GIS,” focuses on the application of
geographic information science in landscape
architectonic research and design. The core of his work
deals with theories, methods and techniques in the
field of landscape architecture and urban design,
visual landscape assessment and visual knowledge
representation. He is leader of the architecture and
landscape research program, series editor of RiUS and
advisor to governmental and regional authorities in
the Netherlands.
55 CTBUH Organizational
Structure & Member Listings
“The framework as presented carries the
potential to underpin a city’s guidance on tall
building development. This framework presents
the context of a tall building design, providing a
more balanced evaluation of a design proposal
compared to studies that focus solely on
individual tall buildings.”
The planning and construction of tall buildings is often controversial, polarizing the public
debate on architecture and urban life. In many cases the emotional discourse focuses on
aesthetics and view corridors, more than city planning or economics. This paper introduces a
framework that analyzes the visual impact a developing skyline has on a city and its
surrounding region, using Rotterdam as a case study. By studying the height and completion
year, identifying the tall building cluster as it is perceived visually and conducting a GIScbased visibility analysis, the framework provides context to tall building designs. The results
make the assessment of individual projects more scientific and balanced, removing many of
the emotional elements that often enter into the discussions.
Introduction
Research on the visual impact of tall buildings
has the potential to make or break a tall
building proposal. In the UK, debates over the
appropriateness of projects in London and
Liverpool are focused on view corridors, with
UNESCO threatening to remove world
heritage designations from historic complexes
if the new developments damage their
aesthetic impact (see “Debating Tall”).
Concerns about the appropriateness of tall
buildings in the urban environment, the
quality of the architecture and the impact on
local real estate markets is increasingly
reflected in municipal and metropolitan
policymaking. Prominent cities with a
longstanding tradition of urban management,
building regulations and zoning plans often
feel the need for additional instruments to
control the development of what is described
by McNeill as “an extremely complex spatial
phenomenon” (McNeill, 2005). Scientific
literature, however, often neglects the
substantial impact skyscrapers and their visual
footprint can have on urban life. “The
significance of these buildings – in terms of
height, levels of human occupancy, aesthetic
impact and popular representation and use
– is in need of careful geographical
interpretation.” (McNeill 2005)
In 2007 the Netherlands Institute for Spatial
Research (Lörzing et al. 2007) published an
investigation on the visibility of the proposed
Belle van Zuylen tower. At 262 meters the
Belle van Zuylen tower would become
Holland’s tallest residential building and the
centerpiece of Leidsche Rijn, the new city
district, west of Utrecht. But the Netherlands
Institute for Spatial Research analysis showed
that the Belle van Zuylen could be seen from
most of the “Green Heart,” the semi-rural
region enclosed by the cities of Rotterdam,
Amsterdam, The Hague and Utrecht. The
report was the last blow for the proposed
development – construction was cancelled
soon after the release of the report (Lörzing
2011).
The Belle van Zuylen case is a fine example of
using research for tactical purposes through
the selective presentation of findings. The
study did not present the Belle van Zuylen in
its true context. The joint visual impact of all
the tall buildings in the region on the Green
Heart was not considered, nor how much that
impact would change as a result of the
construction of the Belle van Zuylen. If the
study had included these elements, it may not
have caused such stir. In fact, a nearby
television tower, the 367-meter
Gerbrandytoren tower, built 42 years earlier,
dominates the visual impact of the area.
A framework that helps to picture the context
of a proposed tall building can potentially
neutralize public and political debates that so
often lead to polarization. This framework is
based on three key elements:
Rotterdam’s tall building development
Rotterdam is one of the prominent European
tall building cities with a mature tall building
policy in place (see Figure 1). Several
databases, including the CTBUH’s The
Skyscraper Center, make it clear that only four
Figure 1. Rotterdam as a prominent west European tall building city © authors
30 | Developing Rotterdam’s Skyline
CTBUH Journal | 2011 Issue II
CTBUH Journal | 2011 Issue II
western European cities possess this type of
mature skyline: London, Paris, Frankfurt, and
Rotterdam.
The leading position of Rotterdam is
furthermore underscored by DEGW’s report
on London’s Skyline, Views, and High Buildings
commissioned by the Greater London
Authority (GLA). The London policy document
uses the same four European cities to
compare established European practices of
tall buildings policymaking: London, Paris,
Frankfurt, and Rotterdam.
The tall building policy document that
emerged in the Netherlands is called
hoogbouwbeleid or hoogbouwvisie. The Dutch
policies resemble a number of policy
documents recently produced in the United
Kingdom and Germany.
Height regulation is a key component of all
these tall building policies. Height also
translates into visibility.
A modern history
Over the years, the city of Rotterdam has
carefully cultivated an image as a “city of
architecture.” But “historic” architecture is not
Rotterdam’s strong point. Few buildings were
left standing after the bombing and fire of
May 1940. The few buildings that survived
were relatively modern buildings from the
1920s and 1930s. The city had to rebuild its
center from scratch. Planners seized this
opportunity to experiment with architecture
and urbanism, which is why the Rotterdam
city center now contains numerous
monuments and icons from the modern and
modernist period, sometimes referred to as
“reconstruction architecture.”
Discussions about the appropriateness of tall
buildings surfaced from time to time, but
never reached the emotional levels
experienced in cities with a historic center. Tall
buildings are now generally accepted and
most are concentrated in the city center.
While Rotterdam as a whole uses modern and
modernist architecture to promote itself, tall
buildings are an essential ingredient in the
profile of the city: the skyline, including the
famous Erasmus Bridge, has become the city’s
iconic image (Ulzen 2007).
Rotterdam’s semi-official tall building history
portrays a 100-year prelude from the late 19th
century, with the completion of the 42-meter
Witte Huis, built in 1898, to the so-called “first
wave” of high buildings in the mid-1980s.
Prominent city planners suggest that the city
at the turn of the century was on the verge of
a “second wave” of tall buildings, which would
feature supertall buildings (Maandag 2001).
However, this tale cannot be underpinned
with facts. Neither the height nor the location
of the high buildings dating from this early
period relate to the municipal policy on
high-rises. It was only in the 1970s that the
current tall building area in the middle of the
city center began to emerge.
Essential data on tall buildings can be easily
presented by means of a scatter plot. In the
case of Rotterdam, the building height and
the year of completion were plotted,
including the primary use of such buildings.
The beauty of Rotterdam’s scatter plot lies in
the clear patterns that emerge. In her book
Form Follows Finance, Carol Willis explains
that the end of a tall building wave is typically
marked by the construction of the “tallest
building so far.” If we would consider these
“tallest buildings so far” as anomalies and
disregard them, the development of the
Rotterdam tall building cluster is characterized
by a remarkable continuity. However, if Carol
Willis’ insights are applicable to Rotterdam,
then the year in which the tallest building so
far was completed could be used as the
breaking points between tall building waves.
Three such buildings stand out in Rotterdam:
the Faculty of Medicine of the Erasmus
University, also known as Hoboken (1969, 112
meters), the Delftse Poort (1991, 93 and 151
meters) and the Maastoren (2009, 165 meters).
If the tall building history of Rotterdam is
indeed characterized by waves, then these
buildings are indicative of three such waves,
as represented in the scatter plot (see Figure
2). The end of the wave is determined by the
latest and tallest building in a development
cycle.
A first wave of tall building construction
began in Rotterdam in the early 1970s and a
second wave followed in the late 1980s and
early 1990s. This second wave is not only
defined by architectural height. The 
Developing Rotterdam’s Skyline | 31
“Although commonly classified as a typology of high-energy
demand, tall buildings can be beneficial in hot, humid
climates. Considering both urban and building scales, the
typology enhances the exposure of the built form to wind
flow, generates more wind at the ground level and provides
desirable shadows upon the immediate surroundings. ”
Suraksha Bhatla & Joanna Gonçalves, page 24
CTBUH Journal | 2012 Issue II
Inside | 3
The Environmental Performance of the TTDI
Suraksha Bhatla
Joana Gonçalves
Authors
Suraksha Bhatla
t: +91 98400 94314
e: [email protected]
Joana Gonçalves
Laboratório de Conforto Ambiental e Eficiência
Energética, Universidade de São Paulo
Rua do Lago 876, Cidade Universitária
São Paulo-SP, CEP 05508-080
Brazil
t: +55 11 30914538
f: +55 11 30914539
e: [email protected]
Suraksha Bhatla
Suraksha graduated with honors from the School of
Architecture and Planning, Anna University, Chennai in
2007 and went on to practice at T.R Hamzah and Yeang
Sdn, Bhd in Kuala Lumpur. She was closely involved
with the design phase of several large scale mixed-use,
residential and commercial tower projects in Asia that
were driven by sustainable concerns, including the
Fusionopolis Office Tower, Singapore and PutraJaya
Commercial Development, Kuala Lumpur, Malaysia. In
2009 she chose to return to academica and pursued
her Masters in Sustainable Environmental Design at
the Architectural Association, London. Her research at
the AA, “Tall Communities: Passive Urban Housing for
the Tropics” focused on the analytic exploration of
basic bioclimatic strategies for hot humid climates and
its consequent social impacts through passive design,
with an emphasis on residential towers in keeping
with the Asian mass housing market.
Joana Gonçalves
Joanna is an architect and urbanist from the faculty of
Architecture and Urbanism of the Federal University of
Rio de Janeiro, where she graduated in 1993. She
practiced as an architect in Ana Maria Niemeyer SA, in
Rio de Janeiro between 1992 and 1995. In 1996 she
moved to London to study environmental design in
the Architectural Association Graduate School,
obtaining a MA degree from the Environment and
Energy Studies Program in 1997. In the same year she
moved to Sao Paulo to engage in teaching and
research in the Faculty of Architecture and Urbanism at
the University of Sao Paulo, where she received a PhD
in 2003 with the thesis entitled, “The Sustainability of
the Tall Building.” Since 1998 she has been involved in
teaching, research and consulting related to
environmental design, collaborating with institutions
in Brazil and in the U.K. Since 2009 she has been part of
the teaching staff of the Masters Programme in
Sustainable Environmental Design of the Architectural
Association, London. In 2011 she was a visiting lecturer
in the Harvard Graduate School of Design. Main
research projects include the recent publication of the
book The Environmental Performance of Tall Buildings.
24 | The Environmental Performance of the TTDI
“Through detailed analysis of occupant
behavior, the predicted energy consumption
patterns shown in modeling and performance
assessment techniques can be further improved,
challenging the preconceived theoretical notion
of comfort and behavioral patterns.”
Tropical Asia is accelerating towards vertical densification of its urban communities. With this
movement comes an increase in the cooling demand in the building sector. Currently, it is
estimated that 60% of the world’s electricity consumption, usually affiliated with high CO2
emissions, is attributable to residential and commercial buildings, creating the need to look at
ways of reducing energy consumption in these buildings (Laustsen 2008). Although
commonly classified as a typology of high-energy demand, tall buildings can be beneficial in
hot, humid climates. Considering both urban and building scales, the typology enhances the
exposure of the built form to wind flow, generates more wind at the ground level and
provides desirable shadows upon the immediate surroundings.
Introduction
Across southeast Asia several proclaimed
“bioclimatic towers” stand as examples of the
contemporary environmental approach to tall
buildings in the tropics, including the two residential towers of the Taman Tun Dr. Ismail
(TTDI) condominiums in Kuala Lumpur (see
Figure 1). Completed in 2006, the 21- and
28-story towers were designed by T.R Hamzah
& Yeang, who is widely known for advocating
his ideas on ecological architecture for the
tropics. Ken Yeang’s buildings are designed to
encourage the inhabitants to connect with
the natural environment through semi-outdoor transitional spaces and other elements
which help reduce energy use. His design
approach incorporates shading elements
such as balconies, sky lobbies and brise-soleil,
with shafts and structural cores often
strategically positioned to buffer the interior
spaces from solar exposure. Wind catchers are
also commonly used to enhance natural
ventilation and vertical landscaping is claimed
to act as a means of facilitating micro climatic
mediation (Yeang 1996).
To evaluate the effectiveness of these different
strategies, including shading devices and
wing walls, a review of the environmental
performance of the TTDI tower was based on
the outcomes of a post-occupancy evaluation
(POE). This included real time data measure-
ments of internal environmental conditions,
namely temperature and humidity, interviews
with the occupants and the assessment of
energy bills. While the field work brings insight
into the reality behind the various energy and
thermal comfort demands of residents, it also
sheds light on their adaptive behavioral
response to environmental conditions and
architectural features offered by principles of
Figure 1. Taman Tun Dr. Ismail (TTDI) condominiums,
Kuala Lumpur © T.R Hamzah and Yeang
CTBUH Journal | 2012 Issue II
Base Case - Thermal Analysis Simulation (TAS) inputs
Floor Area
100 m² (10 x 10 m)
Floor Height
3 m W/F Ratio
25%
Internal Gains
5562 kwh year Thermostat
Upper Limit 30 C
Lower Limit 18 C U-value
0.3 / 0.8 / 3.0 W/m²K Aperture Type
Natural
Ventilation
Infiltration
0.5 ach
Ventilation
Rate
0 ach
partially open - 20C
fully open - 28 C Table 1. Inputs for Base Case TAS model
bioclimatic design. Findings from the study, as
well as a technical review, revealed the
method and extent by which the annual
cooling demand in residential tall buildings
located in the tropical region can be curtailed.
Figures as low as 5–7 kWh/m² per year in the
best case scenario were found, mainly due to
the occupants’ behavior, which had a
fundamental role to play in achieving strong
environmental performance.
The Study
The POE was carried out in two phases: the
first phase included a general survey in a
Figure 2. Relationship of annual cooling load and horizontal
shading depth in different orientations, based on thermal
dynamic simulations using EDSL, 2010 (TAS v 9.1)
group of flats, which in turn, informed a more
detailed study of three residential units in the
second phase of the evaluation. Prior to the
case study, basic practices of environmental
design for the tropics were tested in a series of
analytical studies with the support of
advanced simulation tools. The studies were
carried out for the climatic context of Kuala
Lumpur and supported the subsequent
technical critical assessment of the TTDI
residential complex.
The main aim when dealing with warm
humid climates is to keep the building
envelope protected from the typically high
solar radiation, both direct and diffused, while
ensuring effective heat dissipation by means
of controllable ventilation. The tropical city of
Kuala Lumpur (3.1˚N, 101.5˚E), has a warm,
humid climate throughout the year with
average hourly temperatures remaining at
27˚C for 76% of the year and humidity levels
ranging between 60 to 80%. During the
hottest period of the year, between February
and April, external temperatures exceed 30˚C.
In this context, the diurnal temperature
differences range between 8 and 12 K,
indicating the potential of night time cooling
by means of natural ventilation (ASHRAE
2009a). Due to the proximity to the equator,
Kuala Lumpur receives high levels of solar
radiation (170–200 W/m² per day on the
horizontal plane), highlighting the importance
of shading. Apart from the direct component,
the diffuse radiation is also high (>100 W/m²),
as a consequence of high cloud cover that
occurs for 80% of the year. Given the average
monthly temperatures, based on Auliciems
adaptive model (1981), a theoretical comfort
zone was established as 22.9 –29.9˚C 1. It is
important to note that the prevailing winds in
Kuala Lumpur blow mainly from west and
southwest for most of the year, with an
average speed below 2 m/s for 70% of the
time.
Bioclimatic Strategies
In order to demonstrate the energy saving
potential of passive strategies for tall buildings
in the tropical context, the efficiency of
shading was tested through computer
simulation techniques using thermal analysis
software 2. Parametric studies were carried out
using a base-case of a 10 x 10 meter
residential unit positioned in an intermediate
floor of a hypothetical tall building in Kuala
Lumpur. Considering the limit of 29.9˚C
established by the theoretical comfort zone,
the annual cooling loads for the base case
was simulated with the thermostat set point
at 30˚C for a continuous occupation period of
24 hours (see Table 1). This set point was also
determined based on research precedents 3
and findings from the fieldwork survey of TTDI
residents, which identified the threshold
temperature varying between 29˚C and 30˚C.
The performance of varying shading depths
was analyzed for a 25% window to floor ratio4,
using north-south and east-west orientations.
Looking at orientation only, 15% reduction of
annual cooling loads was found when
comparing the east-west to the north-south
orientations. With the introduction of a
one-meter horizontal shading device, the
loads reduced further by nearly 28% (see
Figure 2). With three-meter deep shading, the
cooling loads reduce further to become
similar for windows facing either north-south
or east-west, making orientation a nondifferentiating parameter for the
environmental performance of the residential
unit. In addition, simulations verified that
there is no negative impact 5 on the internal
daylight distribution for the given base case,
even with a three-meter deep shading device
(see Figure 3 and Table 2).
Insulation produced a perhaps surprising
initial reduction of 42% in annual cooling
loads by improving the U-value of the
external walls from 3.0 W/m²K, which is 
Auliciems, A.(1981). The comfort equation (Tn = 17.6 + 0.31To ± 2.5°C) was used as the neutral temperature found, was closest to the values accepted by tropical subjects in fieldwork survey.
Environmental Design Solutions Limited 2010, (TAS v 9.1) Dynamic thermal simulation TAS model uses hourly values of incident solar radiation and outdoor temperature, to simulate internal
temperatures and cooling energy requirements based on a given set of specific internal environmental, constructional and occupancy conditions for the entire year.
3
BUSCH (1992) Bangkok, Thailand (1100 surveys) 28.5 ET (NV) 24.5 ET (A/C). DeDear (1991) Singapore (583 NV/ 235 A/C surveys) 28.5 ET (NV) 24.2 ET (A/C). Indraganti, M. (2010) Hyderabad,
India (100 surveys) 29.23 (NV).
4
The 25% window to floor ratio (WFR) was chosen for the parametric studies, as simulation test results of different WFR and the consequent cooling load demand revealed that at this point the
ventilation is effective, thereby causing a slight reduction in the cooling loads. Also mass housing schemes in the tropics usually use large glazing areas with WFR between 20–35%.
5
Even with a 2.5-meter shading depth for 10x10 meter unit, double side lit, with a 25% window to floor ratio, it was found that the average daylight factors of 5% can be achieved above the
recommended 1–1.5% for living spaces as per CIBSE 1999 (see Table 2).
1
2
CTBUH Journal | 2012 Issue II
The Environmental Performance of the TTDI | 25
Figure 3. Performance of daylight distribution along the
ten-meter-room depth of the base case, using Radiance
(v3.5) and Ecotect 2010, (v 4)
Figure 4. Annual loads of concrete building structure with
different U-values in W/m²K oriented north south, based on
thermal dynamic simulations using EDSL, 2010 (TAS v 9.1)
conventional construction practice in
concrete without insulation, to 0.8 W/m²K,
when 400 millimeters of mineral wool
insulation is applied to external walls (see
Figure 4). Moreover, the cumulative positive
impact of shading and insulation resulted in
more than 50% reduction in annual cooling
loads in comparison to the base case (no
shading and no insulation), effectively
decreasing from 100.3 kWh/m² to 49.4 kWh/
m² per year. At this stage, the potential of
cooling through natural ventilation had not
yet been considered.
must be said that the reduction was marginal,
approximately 4 to 8%, in comparison to the
optimum combination.
The findings from the first steps of the
analytical work are summarized in Table 3,
showing the reductions in cooling loads of
different combinations, with various degrees
of shading depths and U-values. The most
cost-effective and optimum combination
proved to be the one-meter overhang with
the U-value of 0.8 W/m²K 6. The further
reductions in cooling loads were possible
with increased shading depth from 1 to 3
meters and increased insulation. However, it
Once the envelope was made robust with
shading and insulation, the analytic work
focused on the study of different ventilation
scenarios and its consequent effect on the
reduction of annual cooling loads. At this
point, size, form and layout of the theoretical
base case were modified to represent a typical
layout within the residential unit, commonly
observed within the typology. This was done
to explore if the differences in the
performance was similar for the different
ventilation conditions, and heights, owing to
the various degrees of exposure to the
outside (namely one, two, and three façades)
(see Table 4 and Figure 5).
Expectedly, the overall performance is similar
in different exposures and orientations, due to
the solar protection optimization tactics.
Results show some slight variations between
the different ventilation strategies, as
indicated in the cooling loads. The most
problematic case was identified in the
west-facing orientation, with single-sided
ventilation. For this specific case, the analytical
work showed that by providing opportunities
for cross ventilation, including vertical floor
voids (as seen in the TTDI project) and better
aperture distribution, the thermal
performance of the west-oriented and single
exposed unit could be improved significantly.
Annual cooling consumption dropped by
25% at typical intermediate floor levels (30
meters above ground) and by only 19% at top
floor level (60 meters above ground). This
difference in reduction is due to the impact of
high horizontal solar radiation, despite the
higher wind velocities at the top. With the
addition of a double roof 7 painted white, the
top floor units’ performance could be further
improved to 30% to emulate the typical units.
Case Study: The TTDI Tower, Kuala Lumpur
The TTDI residential complex consists of two
towers, one oriented north-south and the
other east-west. Due to the impact of solar
radiation, in principle, the north-south
oriented tower is likely to have a better
environmental performance, which is why it
was chosen for this study. The 21-story north
facing tower includes 120 apartments, which
house middle and upper middle class families
with two- to four-people per household.
Some of the signature bioclimatic features
incorporated in this project are the
continuous 1.2-meter deep shading device;
white concrete façades to reflect solar
radiation (see Figure 6); 0.6-meter-wide wing
Window to floor ratio/shading depth
15%
20%
25%
Insulation (U-Value, W/m2K)
30%
Shading (m)
3.0
1.0
-41.5%
2.0
-49.0%
3.0
-52.4%
83.6
-16.6%
76.3
-23.9%
73.1
-27.1%
1m
5.05
6.65
7.69
8.33
1.5 m
4.45
5.79
6.68
7.19
2m
4.11
5.27
5.91
6.41
2.5 m
3.84
4.9
5.53
5.91
Table 2. Showing above 5% average daylight Factor for different Window to Floor Ratios
and shading depths, based on simulations for Kuala Lumpur using Radiance (v3.5) and
Ecotect 2010, (v 4)
-22.6%
40.0%
0.8
49.4
-50.8%
41.7
-58.4%
38.3
-61.8%
-57.0%
8.0%
0.3
-63.3%
43.2
-57.0%
35.3
-64.8%
31.9
-68.2%
Table 3. Findings from the analytical work showing the combined contribution in
reduction of cooling loads, with respect to degrees of shading and insulation. The
percentage below is the amount of reduction
The U-value of 0.8 W/m2K can be achieved with 400 mm mineral wool added to the external concrete walls or simply with lightweight concrete blocks (hollow blocks) commonly found in the
local construction sector, to which high-reflectance colors can be easily applied.
7
A double roof is a non-structural exterior slab placed over the structural roof of a building, common in tropical buildings, it protects the top floor against horizontal solar radiation. The analytic
work prescribes a Super insulated Inner roof slab of 0.3 W/m2K, shaded by outer roof both with a surface reflectance of 0.6 and U-value of 0.8 W/m2K
6
26 | The Environmental Performance of the TTDI
CTBUH Journal | 2012 Issue II
Figure 5. Modified base case for the TAS model EDSL 2010, (TAS v 9.1)
walls located on the
east-west faces to
capture wind and
enhance air flow across
the center of the
building; and, finally, a
double roof covering the
top floor flats. The typical
layout of the floor plate is
divided by a six-meter
wide corridor flanked by
four flats on either side,
Figure 6. TTDI tower, north-south orientation, white façades and shading devices to reflect incident solar radiation © T.R
Hamzah and Yeang
each 10 meters deep. The floors are
connected vertically by two-meter wide voids,
which allow light and airflow, designed to
serve the communal circulation areas of the
flats (see Figure 7).
The fieldwork took place during the summer
period, from June 30 to July 7, 2010. Of the
120 flats, 42 households responded to the
general survey on their lifestyle and
occupational pattern, as well as their thermal
comfort expectations. This data revealed that
the air-conditioning thermostat settings
during summer varied from 22 to 26˚C for
middle-aged people (<50 years) and 26 to
28˚C for elder residents (>50 years).
Interestingly, 90% of inhabitants who were
interviewed expressed their preference for
natural ventilation to mechanical and
declared that they exercised window control
as their first response to dealing with higher
indoor temperatures. However, the survey
also showed that occupants’ satisfaction levels
varied based on occupant perception, floor
height and window adaptability.
In this respect, residents in the west-facing
corner flats, with three external façades in the
plan Flats A and E, considered the bedrooms
“hot” in the afternoons, while occupants of
those facing east, in the plan Flats D and H,
found bedrooms and kitchens “warm” in 
Optimized Base Case with Internal Layout TAS inputs
Mean height of surroundings - 40 m
100 (10 x 10 m)
Floor Area
Living Room
50 m2
Bedrooms
25 m2
Floor Height
3 m W/F Ratio
25%
Internal Gains
5562 kwh year Thermostat
U-value
Aperture Type
Upper Limit 30 C
Lower Limit 18 C External Walls
0.8 W/m²K
Glazing
5.6 W/m²K
Natural
Ventilation
Infiltration
0.5 ach
Ventilation
Rate
0 ach
partially open: 20C
fully open: 28 C Table 4. Inputs for TAS model of the Modified Base case
EDSL 2010, (TAS v 9.1)
CTBUH Journal | 2012 Issue II
Figure 7. Typical floor plate with the naturally ventilated corridor and vertical floor voids to bring in daylight access and
enhance air movement across the inner parts of the building (Source –T.R Hamzah and Yeang). © T.R Hamzah and Yeang
The Environmental Performance of the TTDI | 27
Figure 8. Shallow depth of floor voids
Figure 9. Detailed post occupancy evaluation of flats
located at different heights facing north
late mornings. Such responses imply that the
impact of solar radiation was experienced by
occupants in those critical times as a
consequence of the disproportionate shading
depth, in relation to the considerably large
window areas, with 30–35% of the windowto-floor-ratio, on the east and west façades.
The rooms adjacent to the vertical floor voids,
which should be the ones that benefit the
most from the internal cross ventilation
through the stack effect, also had an issue, but
this time related to the restricted access to
ventilation. The occupants kept the windows
closed for privacy reasons, due to the
perceived narrow depth of floor void of just
under two meters (see Figure 8). On the other
hand, the design of the open perforated wide
corridors at all levels, allowed ample cross air
movement that ameliorated the heat
dissipation from the flats, when windows and/
or doors were partially opened.
Energy
Clothing
Occupant
Cases Consumption
Insulation
Profile
year
(Clo)
Flat A
Flat B
Flat C
15 (kWh/m2
per year)
40 (kWh/m2
per year)
25 (kWh/m2
per year)
Room
Occupancy
Getting Closer
Following the more generic survey, a more
detailed post occupancy evaluation took
place in three residential units located on
three different floors, including Flat A located
at the 13th floor, Flat B on the 7th and Flat C on
the 18th floor, all facing north (see Figure 9). In
this case, all three flats had two occupants of
Indian origin over the age of 53. The
differences in floor heights were crucial to
demonstrate the impact of height on the
effectiveness of ventilation and solar
protection strategies, and ultimately, the
resulting energy performance of the flats.
Table 5 shows the occupancy pattern of the
three flats, including time schedule, thermal
comfort conditions, window operability and
overall energy consumption.
The energy bills for the year of 2010 showed
significant variations among the three flats
with a range of 25 to 45%. Considering
air-conditioning systems and fans account for
30 to 45% of the total consumption (CETDEM
2005) of the average electricity consumption
breakdown by the end user of residential flats
in Kuala Lumpur, it could be assumed that out
of the 15 Kwh/m² per year consumed in Flat
A, the energy for space cooling can be as low
as 5 to 7 Kwh/m² per year based on varying
occupancy patterns. This figure indicates that
Flat A is not only the least dependent on air
conditioning, but also probably the only one
among the three which is naturally ventilated
for most of the year. Given the similarities in
the occupancy pattern, differences between
flats can be narrowed down to two factors:
the differences in comfort standards, and the
degree of climatic adaptation. For instance, it
was identified that during the summer nights,
the residents of Flat A prefer the use of fans
rather than air-conditioning, unlike the
occupants in Flats B and C.
Pattern of Occupation (hours)
0:00–7:00
8:00–12:00
13:00–15:00 16:00–20:00
21:00–24:00
Metabolic Window/Door Operation Schedule
Rate (Met) Morning Noon Evening Night
Mother
(age 74)
0.54–0.84
Son
(age 46)
0.29–0.36
Bedroom
Wife
(age 57)
0.54–0.84
Living
Husband
(age 60)
Kitchen
2
0.29–0.36
Mother
(age 76)
Son
(age 53)
Living
1–1.7
open
close
open
close
Kitchen
2
open
open
open
close
0.8
close
close
close
close
1–1.7
open
close
open
close
open
close
open
close
Bedroom
0.8
close
close
close
close
0.54–0.84
Living
1–1.7
close
close
close
close
Kitchen
2
open
open
open
close
0.29–0.36
Bedroom
0.8
close
close
close
close
Table 5. Comparative data from the POE of the three flats (A, B & C) in the TTDI north-south residential tower
28 | The Environmental Performance of the TTDI
CTBUH Journal | 2012 Issue II
100 % RH
35 C
Air-conditioning in use
90 % RH
Solar gains from east
30 C
80 % RH
25 C
70 % RH
Alucieums comfort zone 23-29°C
60 % RH
20 C
50 % RH
15 C
40 % RH
0C
0 % RH
7/7/2010
WEDNESDAY
7/8/2010
THURSDAY
0
+1
+2
7/10/2010
SATURDAY
Datalogger
Occupant thermal perception
Slightly warm
-3
-2
-1
ASHRAE scale
7/9/2010
FRIDAY
+3
Internal temperature
External temperature
Internal humidity
External humidityy
Occupied
Figure 10: Flat B, air temperature and humidity measured in the master bedroom between 7th July and 10th July 2010, compared to the external climatic conditions.
Figure 10. Flat B, air temperature and humidity measured in the master bedroom between July 7 and July 10, 2010,
compared to the external climatic conditions
100 % RH
35 C
Insufficient shading for give glazing area – Gains from West
Windows closed
when occupied
30 C
90 % RH
80 % RH
25 C
70 % RH
Alucieums comfort zone 23-29°C
60 % RH
20 C
50 % RH
15 C
40 % RH
0C
0 % RH
7/1/2010
THURSDAY
7/2/2010
FRIDAY
Occupant thermal perception
Neutral
-3
-2
-1
ASHRAE scale
0
+1
+2
+3
Internal temperature
External temperature
Internal humidity
External humidityy
Occupied
7/3/2010
SATURDAY
7/4/2010
SUNDAY
Datalogger
Figure
11.A,Flat
A, air temperature
and humidity
measured
in the1stmaster
between
June,
30 and
Julyconditions.
7, 2010,
Figure
11: Flat
air temperature
and humidity measured
in the master
bedroom between
July and bedroom
4th of July 2010,
compared to
the external
climatic
compared to the external climatic conditions
CTBUH Journal | 2012 Issue II
In addition, in some particular rooms in Flats B
and C, where natural ventilation was
preferred, ergonomic issues such as improper
room dimensions for furniture layout and
privacy requirements inhibited more flexible
use of windows, which was seen previously in
the wider survey. As a result this caused poor
ventilation, closure of the internal blinds and
the inevitable increased dependency on
artificial cooling, mechanical ventilation and
artificial lighting (see Figure 10). In terms of
solar exposure, Flat B on the 18th floor receives
considerably more solar gains than the other
two flats due to its position at a higher floor,
despite the double roof. In addition, the
architectural layout of the building floor plate,
allowed direct solar radiation from the internal
open corridor and adjacent voids in the
central part of the building heating the
service and secondary bedrooms of the flat.
Furthermore, the kitchen was found to be
“hot” in Flat B due to the closed plan layout.
In comparison to Flat B, Flat A has an
advantageous position in the TTDI Tower. With
the main orientation towards north and west,
the exposure of three façades coupled with
the proximity to the wing wall creates the
appropriate conditions for good airflow within
all rooms. The open-plan conversion created
by the resident enhanced cross ventilation in
the kitchen area where the most internal
gains are concentrated. It also improved the
daylight penetration from both sides, namely
west and north, reducing the demand for
artificial lighting. The west facing service areas
were shaded in the direction of the prevailing
winds and flanked with wing walls, enhancing
the cross airflow. Data loggers measuring
temperature and humidity were placed for
four days in the living room, master and
secondary bedrooms in Flat A. In all cases the
air temperatures remained relatively stable
and below 30˚C, except in the west facing
master bedroom due to overheating. Based
on the findings from the simplified analytical
studies, the overheating effect was
presumably a consequence of the impinging
afternoon sun on an uninsulated wall (see
Figure 11). In this case, the surface
temperatures recorded on the west facing
walls were 2˚C higher than external
temperature at 7 p.m., after sunset. 
The Environmental Performance of the TTDI | 29
Nevertheless, the overall thermal conditions
of the rooms in Flat A indicated good thermal
and energy performance.
Apart from the capacity of the architectural
design to modulate the variable and
sometimes undesirable indoor and outdoor
conditions, the good environmental
performance of Flat A is inextricably linked to
the willingness of its residents to exercise
adaptive behavior. These included opening
and closing windows, controlling the internal
blinds and curtains, as well as sleeping close
to the ground or under the ceiling fans.
Considerations and Key Findings
The initial analytic work showed that shading
of windows and walls is the most effective
passive approach for the tropics. The
base-case considered a window-to-floor ratio
of 25%, which proved to have a good impact
on daylight and ventilation, yet was still large
enough for generous views of the scenery
outside. For windows of such proportion, a
shading solution between one to two meters
deep, in principle, can be efficient. However
precise shading devices need to be
determined based on glazing area and
orientation. Moreover, contrary to common
belief, insulation has a huge potential to
reduce the overall cooling load demand in
...Pritzker
“
The fact that an
architect from China has
been selected by the jury
represents a significant step
in acknowledging the role
that China will play in the
development of
architectural ideals.
”
Thomas J. Pritzker, explaining the selection
of Chinese architect Wang Shu for the 2012
Pritzker Prize. From “Chinese ‘Amateur’ Wins
Prestigious Architecture Prize,” CNN,
February 28, 2012.
30 | The Environmental Performance of the TTDI
warm-humid climates like Kuala Lumpur,
while contributing to more stable internal
temperatures throughout the day. The study
recommends insulating concrete walls with
U-values of 0.8 W/m²K (400 millimeters
mineral wool) to be beneficial when applied
externally. Environmentally, shading and
insulation improves energy performance by
50%, making the unit robust to climatic
variations and, therefore, passively
conditioned for longer periods.
Apart from providing a comparative benchmark of 15 kWh/m² per year for electricity
consumption for future residential units in tall
buildings in the tropics, the fieldwork also
provided some useful insights into the validity
of previous analytical research simulations
with regards to shading and natural ventilation. In fact, residents from the middle and
upper middle class groups, where the use of
air conditioning is a cultural trend, have
actually proven to prefer to naturally ventilate
their apartments, despite the warm humid
climatic conditions of Kuala Lumpur. Constant
air movement has proved to enhance the
residents’ perception of comfort, which is
achieved by exercising adaptive mechanisms
such as opening windows, doors and/or using
low-powered ceiling fans. As a consequence,
ambient air temperature around 30˚C was
found acceptable. On a more critical
observation, the fieldwork also showed the
importance of the relationship between the
internal furniture layout, position and size of
windows. Equally important is the issue of
privacy that must be addressed, especially
when facing common corridors. By designing
buildings with a range of adaptable options–
primarily through smaller windows and blinds
to address privacy, gusty winds and security–
designers can influence occupants to utilize
them and tolerate climatic variability in
naturally ventilated apartments.
It is crucial to understand the way occupants
of existing buildings contribute to overall
energy performance, which provides a
fundamental measure for the achievement of
true environmentally responsive design.
Through detailed analysis of occupant
behavior, the predicted energy consumption
patterns shown in modeling and performance
assessment techniques can be further
improved, challenging the preconceived
theoretical notion of comfort and behavioral
patterns.
The findings from the post-occupancy
evaluation of the TTDI tower offers insight on
the real potential of climate responsive design
and the impact of the occupants’ behavior
and their thermal expectations from the
building. A set of effective design guidelines
for the tropics can be formulated for future
projects by studying the real environmental
performance of more existing tall buildings in
a wider fieldwork study. With the help of more
comprehensive measured data and detailed
analytical investigations, specific design
solutions can be found. 
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CTBUH Journal | 2012 Issue II