ENERGY EFFICIENT DESIGN: 
INVESTIGATION OF URBAN 
BUILT FORMS 
The dissertation presented to the 
Faculty of Architecture of the 
University of Moratuwa, Sri Lanka 
For the final Examination in 
M.Sc. (Architecture) 
And to the Royal Institute of 
British Architects 
For R.I.B.A. (part II) Examination. 
0 7 4 0 9 2 
Nirosha Thilangi Lloyd 
Faculty of Architecture 
University of Moratuwa 
Sri Lanka 
30 t h May 2000 
7 Z oo 
University of Moratuwa 
T ! 
"74092 
ACKNOWLEDGEMENTS 
I am grateful to my supervisors Dr. Rohinton 
Emmanuel & my year masters Dr. L.S.R Perera and 
Dr. Dayaratne for their encouragement, constant 
guidance and critical evaluation through my 
research work. 
Many thanks to Archt. Kapila Silva for guiding me 
to right source of information. 
A special thanks to Archt. R Giridharan for 
providing guidance. 
I am also grateful to Archt. Gamini Weerasinghe 
and friends at Urban Development Authority, for 
providing me valuable information. 
A special thanks to Mohan Thenuwara, Ayesha 
Wijeratne, Sathya Sajeewa, Mangala 
Abewickrama, Ruvini, Champika, and my other 
classmates for their valuable support. 
Finally, I would like to thank my family, specially my 
parents, my brother and all other friends who 
constantly encouraged me in the studies. 
ABSTRACT 
The consideration and necessary attention 
towards natural forces (climatology) has been 
overshadowed by market forces in cities like 
Colombo. In addition to that most of the 
International cities have built forms with borrowed 
culture rather than their own indigenous character. 
These built forms have no bearing on the natural 
forces. As a result they consume very high amount 
of both end-use and embodied energy. The 
manipulation of internal environment with little 
concentration to dynamic and complex issues of 
natural forces has led to environmental 
degradation. Therefore this study analyses the 
cooling energy and thermal comfort implications 
of the changing urban climate of Colombo Sri 
Lanka. More recent climatic average is assumed 
to be indicative of urban heat island 
phenomenon. Using parametric building energy 
simulation software, the dissertation analyses the 
cooling energy and thermal comfort differences 
(based on PMV & OT as the major yard stick) 
arriving from the recent years. Nine options are 
examined to determine their potential to mitigate 
the negative impacts of the altered urban climate. 
CONTENTS 
ACKNOWLEDGEMENTS i 
ABSTRACT ii 
LIST OF TABLES vi 
LIST OF FIGURES vii 
INTRODUCTION 1 
Objectives 4 
Scope & UmRaflons 5 
Hypothesis 5 
Methodology 5 
CHAPTER ONE - ENERGY AND FORM 
1.1 Introduction 7 
1.2 Appraisal of Energy Efficient 
Design 7 
1.3 Appraisal of Urban Built Forms 16 
1.4 Urban Heat Islands 16 
1.4.1 Causes of Heat Island 17 
1.4.2 Urban Geometry and 
Heat Island Effect 18 
1.4.3 Heat Island Effect in 
Colombo 19 
CHAPTER TWO - THEORY AND ANALYTICAL FRAME WORK 
2.1 Introduction 21 
2.2 Theory 21 
2.2.1 Relationship between built 
forms and natural forces 21 
2.2.2 Effect of natural forces on 
building parameters 25 
2.3 Analytical frame work 25 
2.4 General analysis on basic built 
forms based on PMV OT 
iii 
& C o o l i n g E n e r g y 2 6 
2 . 5 S e l e c t i o n o f s i t e s 2 7 
2 . 6 DEROB-LTH 3 1 
2 . 7 C l i m a t i c d a t a 3 4 
2 . 8 P a r a m e t e r s o f s t u d y 4 3 
C H A P T E R THREE - CASE STUDIES 
3 . 1 I n t r o d u c t i o n 4 4 
3 . 2 B a s e C a s e s 4 4 
3 . 3 R e s u l t s 4 9 
C H A P T E R F O U R - ANALYSIS 
4 .1 A n a l y s i s 1 - T h e r m a l C o m f o r t 1 2 5 
••i- 4 . 1 . 1 B a s e C a s e - Y o r k S t r e e t , F o r t 1 2 7 
4 . 1 . 2 B a s e C a s e - C o m m u n i t y 
H o u s i n g , C o l o m b o 5 1 4 6 
4 . 1 . 3 C o m p a r i s o n 1 5 6 
4 . 2 A n a l y s i s 2 - C o o l i n g L o a d 1 6 6 
4 . 2 . 1 B a s e C a s e - Y o r k S t r e e t , For t 1 6 6 
4 . 2 . 2 B a s e C a s e - C o m m u n i t y 
H o u s i n g , C o l o m b o 5 1 6 9 
y 4 . 2 . 3 C o m p a r i s o n 1 7 0 
C H A P T E R FIVE - CONCLUSION 
REFERENCES 
1 7 3 
1 7 7 
A p p e n d i x 1 
A p p e n d i x 2 
IV 
LIST OF TABLES 
T a b l e 1 L o n g - t e r m u r b a n c l i m a t i c c h a n g e s in 
s e l e c t e d U. S . c i t i e s 
T a b l e 2 E f f e c t o f u r b a n i z a t i o n o n c l i m a t i c 
p a r a m e t e r s 
T a b l e 3 C a u s e s o f u r b a n H e a t - I s l a n d a n d t h e i r 
e f f e c t o n m i c r o c l i m a t e 
T a b l e 4 E x i s t i n g c o n d i t i o n s o f s e l e c t e d s i t e s 
T a b l e 5 E x p e c t e d s i t u a t i o n o f s e l e c t e d s i t e s 
T a b l e 6 H i s t o r i c a l D a t a o f s e l e c t e d s i t e s 
T a b l e 7 C l i m a t i c D a t a 
T a b l e 8 B u i l d i n g M a t e r i a l s a n d t h e i r p r o p e r t i e s 
T a b l e 9 M a t e r i a l s o f B u i l d i n g E l e m e n t s 
T a b l e 1 0 C l o t h i n g D a t a 
T a b l e 11 M e t a b o l i c r a t e s a t d i f f e r e n t t y p i c a l 
a c t i v i t i e s a r e d e p i c t e d b e l o w in t h e 
T a b l e 1 2 I n t e r n a l L o a d s ( H o u s e ) 
T a b l e 1 3 I n t e r n a l L o a d s ( C o m m e r c i a l b u i l d i n g ) 
T a b l e 1 4 E q u i p m e n t s a n d t h e i r p o w e r 
a b s o r p t i o n / r e l e a s e 
T a b l e l 5 P a r a m e t e r t a b l e 
y 
ABBREVIATIONS: 
P M V P R E D I C T E D M E A N V O T E 
O T O P E R A T I V E TEMPERATURE 
C M R C O L O M B O M E T R O P O L I T A N R E G I O N 
C M R S P C O L O M B O M E T R O P O L I T A N R E G I O N A L 
STRUCTURE P L A N 
y 
v 
LIST OF FIGURES 
F i g . 1 S h o w s t h a t b u i l t f o r m s , w h i c h a r e n o t in 1 
p h a s e w i t h n a t u r a l f o r c e s c o n s u m e h i g h 
a m o u n t o f e n e r g y f o r m a i n t e n a n c e 
F i g . 2 E x p l a i n t h e w a y in w h i c h t h e 3 
t e m p e r a t u r e i n c r e a s e s in a c i t y c e n t e r 
b y h e a t I s l a n d e f f e c t 
F i g . 3 S h o w t h e e n e r g y c y c l e a n d i n t e r 9 
d e p e n d e n c e o f e n d u s e a n d e m b o d i e d 
e n e r g y r e s p e c t i v e l y 
F i g . 4 S h o w t h e e n e r g y c y c l e a n d i n t e r 9 
d e p e n d e n c e o f e n d u s e a n d e m b o d i e d 
e n e r g y r e s p e c t i v e l y 
F i g . 5 S h o w s t h e e n e r g y c o n s c i o u s l a y o u t o f 9 
M e s a V e r d e s e t t l e m e n t 
F i g . 7 S h o w s t h e e v o l u t i o n o f f o r m w i t h r e s p e c t 11 
t o n a t u r a l t o p o g r a p h y 
F i g . 8 S h o w s t h e h e i g h t o f t h e b u i l t f o r m w i t h 11 
r e s p e c t t o s u m m e r a n d w i n t e r s o l a r 
a n g l e s 
F i g . 9 S h o w s t h a t t h e b a c k y a r d a n d t h e 1 2 
a c c e s s w a y s in D a v i s C a l i f o r n i a a r e 
d e s i g n e d t o r e t a i n t h e r a i n w a t e r a n d 
s a v e t h e e n e r g y f o r w a t e r p u m p i n g 
F i g . 1 0 S h o w s t h e b u i l t f o r m s , w h i c h c o m p l y 1 3 
w i t h t h e O T T V r e g u l a t i o n o f S i n g a p o r e 
F i g . 1 1 G D P - E l e c t r i c i t y r e l a t i o n s h i p f o r Sri L a n k a 1 4 
( 1 9 7 4 - 1 9 9 4 ) 
F i g . 1 2 E n e r g y E f f i c i e n t H i g h R i s e B u i l d i n g s . 1 5 
C o m p a r i s o n s b e t w e e n a t y p i c a l o f f i c e 
b u i l d i n g a n d p r o p o s e d c l i m a t e 
r e s p o n s i v e d e s i g n . 
F i g . 1 3 T h i r t y - y e a r d i u r n a l v a r i a t i o n s in 1 9 
t e m p e r a t u r e d u r i n g t h e h o t t e s t m o n t h in 
C M R 
F i g . 1 4 S h o w t h e g e n e r a l d i s t r i b u t i o n o f s o l a r 2 2 
r a d i a t i o n a n d c h a n g e in s o l a r r a d i a t i o n 
w i t h r e s p e c t t o h e i g h t r e s p e c t i v e l y 
F i g . 1 5 S h o w s t h a t s u r f a c e a r e a c h a n g e w i t h 2 3 
c h a n g e in t h e c o n f i g u r a t i o n o f t h e f o r m 
( n u m b e r i n d i c a t e s t h e n u m b e r o f 
e x p o s e d s u r f a c e s ) 
vn 
F i g . 1 6 S h o w s t h e a m o u n t o f r e f l e c t e d g l a r e t o 
t h e e n v i r o n m e n t f o r m t h e b u i l t f o r m w i t h 
1 0 0 % c u r t a i n w a l l 
2 3 
F i g . 1 7 S h o w s t h e w i n d g r a d i e n t a t d i f f e r e n t 
l o c a t i o n s 
2 4 
F i g . 1 8 & 
F i g . 1 9 
S h o w t h e e f f e c t o f t h e w i n d d u e t o 
d i f f e r e n t h e i g h t a n d l a y o u t o f b u i l t f o r m s 
2 4 
F i g . 2 0 Y o r k S t r e e t , F o r t 2 8 
F i g . 2 1 S t r e e t e l e v a t i o n s - Y o r k S t r e e t , F o r t 2 9 
F i g . 2 2 A n d e r s o n F l a t s , C o l o m b o 5 3 0 
F i g . 2 3 Y o r k S t r e e t 4 4 
F i g . 2 4 Y o r k S t r e e t 4 4 
F i g . 2 5 Y o r k S t r e e t 4 5 
viii