Table Of Content101RULES_PRELIMS–01-07:12x186 04/12/2012 01:49 Page 1
101
RULES
OF
THUMB
For Low Energy Architecture
101RULES_PRELIMS–01-07:12x186 04/12/2012 01:49 Page 2
To Betty
My gratitude is due to Tod Wakefield, Head of School at Portsmouth School of
Architecture, for his encouragement and advice throughout the process of creating this
book. The lack of rules of thumb was identified, in the UK conference series ‘Designs on
the Planet,’ as a hindrance to educators and practitioners. Subsequently, the Centre for
Education in the Built Environment (CEBE) published a case study of mine, which was a
precursor to this book, and I am grateful to Andy Roberts and CEBE.
Many educators, practitioners, colleagues and clients have been an influence over the
years and some of these are: Andy Ford; Professor Edward Ng, who introduced me to
Dean Hawkes, Baruch Givoni and Brian Edwards; Brendan Redican; colleagues and
students at the University of Portsmouth School of Architecture and staff at the University
Library. The thoughts of my own teachers, who threw light on the subject in my formative
years, remain in my mind.
The book would not yet have seen the light of day without the assistance of James Scrace.
I am grateful to RIBA Publishing, and to James Thompson, who immediately saw the point
of the book and enthusiastically set about making it real.
I thank my wife Betty for her steadfast support, as well as Anna and Nick for their
confidence in what they insisted on calling my book.
© Huw Heywood, 2012
Published by RIBA Publishing, 15 Bonhill Street, London EC2P 2EA
ISBN 978 1 85946 481 6
Stock code 78992
HUW HEYWOOD
101
The right of Huw Heywood to be identified as the Author of this Work has been
asserted in accordance with the Copyright, Design and Patents Act 1988.
All rights reserved. No part of this publication may be reproduced, stored in a retrieval
system, or transmitted, in any form or by any means, electronic, mechanical,
photocopying, recording or otherwise, without prior permission of the copyright owner.
British Library Cataloguing in Publications Data
A catalogue record for this book is available from the British Library.
Commissioning Editor: James Thompson
RULES
Production: Kate Mackillop
Designed and typeset by Luis Peral-Aranda
Printed and bound by W & G Baird Limited, Northern Ireland
OF
While every effort has been made to check the accuracy and quality of the
information given in this publication, neither the Author nor the Publisher accept any
responsibility for the subsequent use of this information, for any errors or omissions
that it may contain, or for any misunderstandings arising from it. THUMB
RIBA Publishing is part of RIBA Enterprises Ltd.
www.ribaenterprises.com
For Low Energy Architecture
101RULES_PRELIMS–01-07:12x186 04/12/2012 01:49 Page 2
To Betty
My gratitude is due to Tod Wakefield, Head of School at Portsmouth School of
Architecture, for his encouragement and advice throughout the process of creating this
book. The lack of rules of thumb was identified, in the UK conference series ‘Designs on
the Planet,’ as a hindrance to educators and practitioners. Subsequently, the Centre for
Education in the Built Environment (CEBE) published a case study of mine, which was a
precursor to this book, and I am grateful to Andy Roberts and CEBE.
Many educators, practitioners, colleagues and clients have been an influence over the
years and some of these are: Andy Ford; Professor Edward Ng, who introduced me to
Dean Hawkes, Baruch Givoni and Brian Edwards; Brendan Redican; colleagues and
students at the University of Portsmouth School of Architecture and staff at the University
Library. The thoughts of my own teachers, who threw light on the subject in my formative
years, remain in my mind.
The book would not yet have seen the light of day without the assistance of James Scrace.
I am grateful to RIBA Publishing, and to James Thompson, who immediately saw the point
of the book and enthusiastically set about making it real.
I thank my wife Betty for her steadfast support, as well as Anna and Nick for their
confidence in what they insisted on calling my book.
© Huw Heywood, 2012
Published by RIBA Publishing, 15 Bonhill Street, London EC2P 2EA
ISBN 987 1 85946 481 6
Stock code 78992
HUW HEYWOOD
101
The right of Huw Heywood to be identified as the Author of this Work has been
asserted in accordance with the Copyright, Design and Patents Act 1988.
All rights reserved. No part of this publication may be reproduced, stored in a retrieval
system, or transmitted, in any form or by any means, electronic, mechanical,
photocopying, recording or otherwise, without prior permission of the copyright owner.
British Library Cataloguing in Publications Data
A catalogue record for this book is available from the British Library.
Commissioning Editor: James Thompson
RULES
Production: Kate Mackillop
Designed and typeset by Luis Peral-Aranda
Printed and bound by W & G Baird Limited, Northern Ireland
OF
While every effort has been made to check the accuracy and quality of the
information given in this publication, neither the Author nor the Publisher accept any
responsibility for the subsequent use of this information, for any errors or omissions
that it may contain, or for any misunderstandings arising from it. THUMB
RIBA Publishing is part of RIBA Enterprises Ltd.
www.ribaenterprises.com
For Low Energy Architecture
101RULES_PRELIMS–01-07:12x186 13/12/2012 11:01 Page 4
CONTENTS PREFACE
PREFACE 5
Throughout history, people have constructed buildings with an
intuitive responsiveness towards the environment and the climate
INTRODUCTION 6
in which they live, ensuring their own comfort while respecting
CHAPTER 1. WORKING WITH SITE AND LOCATION 9 limited resources and working with, not against, the forces of
- Sun and shade nature. By returning to an understanding of the basic principles
- Climate and micro-climate involved in the ways that buildings respond to their surroundings,
- Shelter from wind and rain we can significantly reduce energy needs. Guidance on how to
design buildings that need little or no energy for heating, lighting
CHAPTER 2. MANIPULATING ORIENTATION AND FORM 49
and cooling is the specific focus of this book.
- The relationship between sun and wind
- The impact of building form We use energy to heat, light and cool our buildings. Much of the
energy we use is derived from fossil fuels (oil, coal, gas), which are
CHAPTER 3. THE LOW ENERGY BUILDING ENVELOPE 81
finite global resources. They will eventually run out. Before we seek
- Heavy and lightweight construction
to replace this fossil-fuel-derived energy with renewable or
- The timing of heating needs
alternative energy sources (sun, wind, water or plant-based), we
- Reducing heat loss
should first aim to ensure that our buildings use as little energy as
CHAPTER 4. ENERGY AND THE INTERNAL ENVIRONMENT 119 possible, irrespective of where that energy comes from. Any
- Free heating: direct, isolated and indirect solar gain energy source will result, from its production, supply and use, in
- Free cooling: using earth, wind and water negative impacts on the planet.
- Free lighting: daylight
Aside from fossil fuels being a finite resource, there is a second
- Colour
reason to reduce the amount of energy used in our buildings. The
way in which we convert fossil fuels into the energy we use for
CHAPTER 5. RULES AND STRATEGIES FOR DIFFERENT
heat, light and power results in the generation of carbon dioxide
CLIMATIC REGIONS 177
- Hot-dry climate (CO²), one of the greenhouse gases. A link has therefore been
- Hot-humid climate made between buildings, global warming and climate change. In
- Cold climate fact, buildings are responsible for nearly half of all the CO²
- Cold-winter/hot-summer climate emissions we generate.
- Temperate climate Certainly energy is used in the construction of buildings – for
example, from the mechanical excavation of clay to its firing and
NARRATIVE BIBLIOGRAPHY 190
then the transportation of the resulting brick to the construction
BIBLIOGRAPHY 218 site – and this is a serious issue for designers to tackle. But by far
the most energy is used by buildings during their lifetime. All of us
INDEX 222
who commission, design, operate and inhabit buildings therefore
have a significant role, and a responsibility, in reducing the energy
used in the operation of our buildings.
PREFACE 5
101RULES_PRELIMS–01-07:12x186 04/12/2012 01:49 Page 4
CONTENTS PREFACE
PREFACE 5
Throughout history, people have constructed buildings with an
intuitive responsiveness towards the environment and the climate
INTRODUCTION 6
in which they live, ensuring their own comfort while respecting
CHAPTER 1. WORKING WITH SITE AND LOCATION 9 limited resources and working with, not against, the forces of
- Sun and shade nature. By returning to an understanding of the basic principles
- Climate and micro-climate involved in the ways that buildings respond to their surroundings,
- Shelter from wind and rain we can significantly reduce energy needs. Guidance on how to
design buildings that need little or no energy for heating, lighting
CHAPTER 2. MANIPULATING ORIENTATION AND FORM 49
and cooling is the specific focus of this book.
- The relationship between sun and wind
- The impact of building form We use energy to heat, light and cool our buildings. Much of the
energy we use is derived from fossil fuels (oil, coal, gas), which are
CHAPTER 3. THE LOW ENERGY BUILDING ENVELOPE 81
finite global resources. They will eventually run out. Before we seek
- Heavy and lightweight construction
to replace this fossil-fuel-derived energy with renewable or
- The timing of heating needs
alternative energy sources (sun, wind, water or plant-based), we
- Reducing heat loss
should first aim to ensure that our buildings use as little energy as
CHAPTER 4. ENERGY AND THE INTERNAL ENVIRONMENT 119 possible, irrespective of where that energy comes from. Any
- Free heating: direct, isolated and indirect solar gain energy source will result, from its production, supply and use, in
- Free cooling: using earth, wind and water negative impacts on the planet.
- Hybrid heating and cooling
Aside from fossil fuels being a finite resource, there is a second
- Free lighting: daylight
reason to reduce the amount of energy used in our buildings. The
- Colour
way in which we convert fossil fuels into the energy we use for
heat, light and power results in the generation of carbon dioxide
CHAPTER 5. RULES AND STRATEGIES FOR DIFFERENT
CLIMATIC REGIONS 177 (CO²), one of the greenhouse gases. A link has therefore been
- Hot-dry climate made between buildings, global warming and climate change. In
- Hot-humid climate fact, buildings are responsible for nearly half of all the CO²
- Cold climate emissions we generate.
- Cold-winter/hot-summer climate Certainly energy is used in the construction of buildings – for
- Temperate climate example, from the mechanical excavation of clay to its firing and
then the transportation of the resulting brick to the construction
NARRATIVE BIBLIOGRAPHY 190
site – and this is a serious issue for designers to tackle. But by far
BIBLIOGRAPHY 218 the most energy is used by buildings during their lifetime. All of us
who commission, design, operate and inhabit buildings therefore
INDEX 222
have a significant role, and a responsibility, in reducing the energy
used in the operation of our buildings.
PREFACE 5
101RULES_PRELIMS–01-07:12x186 04/12/2012 01:49 Page 6
INTRODUCTION, AND WHAT THE
RULES OF THUMB ARE FOR
Our ancestors knew how to create comfortable indoor conditions unless the result is a transportable architecture, the location and
with modest use of resources in their indigenous architecture and orientation of a building will not change once the building is built,
we must now re-learn their intuitive skills and apply them for whereas the building envelope can be upgraded with additional
tomorrow’s world. This book seeks to reintroduce to the reader insulation, or in response to new technologies which become
that intuitive knowledge, explaining what works in buildings which available. The early architectural considerations have a major
use little or no energy in their operation, wherever they happen to bearing on the energy efficiency of a building. The decisions are
be on the planet. It aims to provide the reader with two things: crucial, and so had better be right: the rules of thumb are there to
- An understanding of the universal rules of nature which govern provide guidance on these early, permanent moves which link our
the way buildings respond to their environment, and buildings with the natural world and which are also key ingredients
of a poetic architecture.
- Specific low energy-use, rule-of-thumb solutions for new
buildings or for retrofitting existing buildings The book aims to be relevant globally, which presents a number of
challenges to author and reader. One difficulty all design teachers
The rules of thumb are about the fundamentals of energy
face is how to refer to where the sun is, a fundamental factor
efficiency. For those who wish to proceed into measurement,
influencing many of the rules of thumb. When referring to the façade
calculation, modelling and further research, a narrative bibliography
of a building which is oriented towards the midday sun the term
provides guidance on the key texts and some of the basic
‘south-facing’ is fine in the northern hemisphere, but in the southern
formulae which lie behind the rules.
hemisphere it traverses the sky in the north, so the façade facing
Buildings exist to modify the climate, from whatever the outside
the sun is north-facing. I have opted mainly to use the awkward, but
conditions might be, to create a comfortable indoor environment.
functional, ‘solar-oriented’ or ‘south-facing (north in the southern
For new buildings the process by which this is achieved is an
hemisphere)’ and, occasionally, ‘equator-facing’. The façade
integrated one which starts with consideration of the siting and
opposite the sun is sometimes referred to, again rather clumsily, as
location of a building, moves to deliberations on orientation and
‘non-solar-oriented’. Hemisphere-centric terms are used only where
form and then on to the design of the building envelope (the walls,
the term is a well known maxim.
roof and floor, also known as the building fabric in this book) and
Finally, a brief glimpse of the future, in which buildings will need to be
to the interior spaces. The final stage is one in which the
more resilient and adaptable to an unpredictable climate. The rules of
occupants decide whether their building has succeeded in creating
thumb are applicable to today’s climate regions and to future
a comfortable environment and if not they make themselves
uncertainties. For example, some temperate regions might experience
comfortable, traditionally by using energy to supply heating or
climates more like the hot-summer/cold-winter climates discussed in
cooling. It is the need for the use of energy which the rules of
the book, meaning that the rules which apply today in winter in cold
thumb seek to limit.
regions and in summer in hot regions will need to be considered.
The design process described above is reflected in the
Through their simplicity, the rules of thumb invite creativity in making
organisation of this book. It is worth noting that the early design
low energy-use buildings and cities which are both delightful and
decisions are more permanent than the later ones: for example,
responsive to human needs in an ever-changing world.
6 101 RULES OF THUMB INTRODUCTION 7
101RULES_PRELIMS–01-07:12x186 04/12/2012 01:49 Page 6
INTRODUCTION, AND WHAT THE
RULES OF THUMB ARE FOR
Our ancestors knew how to create comfortable indoor conditions unless the result is a transportable architecture, the location and
with modest use of resources in their indigenous architecture and orientation of a building will not change once the building is built,
we must now re-learn their intuitive skills and apply them for whereas the building envelope can be upgraded with additional
tomorrow’s world. This book seeks to reintroduce to the reader insulation, or in response to new technologies which become
that intuitive knowledge, explaining what works in buildings which available. The early architectural considerations have a major
use little or no energy in their operation, wherever they happen to bearing on the energy efficiency of a building. The decisions are
be on the planet. It aims to provide the reader with two things: crucial, and so had better be right: the rules of thumb are there to
- An understanding of the universal rules of nature which govern provide guidance on these early, permanent moves which link our
the way buildings respond to their environment, and buildings with the natural world and which are also key ingredients
of a poetic architecture.
- Specific low energy-use, rule-of-thumb solutions for new
buildings or for retrofitting existing buildings The book aims to be relevant globally, which presents a number of
challenges to author and reader. One difficulty all design teachers
The rules of thumb are about the fundamentals of energy
face is how to refer to where the sun is, a fundamental factor
efficiency. For those who wish to proceed into measurement,
influencing many of the rules of thumb. When referring to the façade
calculation, modelling and further research, a narrative bibliography
of a building which is oriented towards the midday sun the term
provides guidance on the key texts and some of the basic
‘south-facing’ is fine in the northern hemisphere, but in the southern
formulae which lie behind the rules.
hemisphere it traverses the sky in the north, so the façade facing
Buildings exist to modify the climate, from whatever the outside
the sun is north-facing. I have opted mainly to use the awkward, but
conditions might be, to create a comfortable indoor environment.
functional, ‘solar-oriented’ or ‘south-facing (north in the southern
For new buildings the process by which this is achieved is an
hemisphere)’ and, occasionally, ‘equator-facing’. The façade
integrated one which starts with consideration of the siting and
opposite the sun is sometimes referred to, again rather clumsily, as
location of a building, moves to deliberations on orientation and
‘non-solar-oriented’. Hemisphere-centric terms are used only where
form and then on to the design of the building envelope (the walls,
the term is a well known maxim.
roof and floor, also known as the building fabric in this book) and
Finally, a brief glimpse of the future, in which buildings will need to be
to the interior spaces. The final stage is one in which the
more resilient and adaptable to an unpredictable climate. The rules of
occupants decide whether their building has succeeded in creating
thumb are applicable to today’s climate regions and to future
a comfortable environment and if not they make themselves
uncertainties. For example, some temperate regions might experience
comfortable, traditionally by using energy to supply heating or
climates more like the hot-summer/cold-winter climates discussed in
cooling. It is the need for the use of energy which the rules of
the book, meaning that the rules which apply today in winter in cold
thumb seek to limit.
regions and in summer in hot regions will need to be considered.
The design process described above is reflected in the
Through their simplicity, the rules of thumb invite creativity in making
organisation of this book. It is worth noting that the early design
low energy-use buildings and cities which are both delightful and
decisions are more permanent than the later ones: for example,
responsive to human needs in an ever-changing world.
6 101 RULES OF THUMB INTRODUCTION 7
101RULES_CHAPTER1:12x186 04/12/2012 01:43 Page 8
CHAPTER 1
WORKING WITH SITE
AND LOCATION
• Sun and shade
• Climate and micro-climate
• Shelter from wind and rain
101RULES_CHAPTER1:12x186 04/12/2012 01:43 Page 8
CHAPTER 1
WORKING WITH SITE
AND LOCATION
• Sun and shade
• Climate and micro-climate
• Shelter from wind and rain
