Creating an Eco-Home. New-build and retrofit: a practical guide (Green Books, for September 2015 publication) EXTRACT

 

Contents

 

1. Introduction: Why, where, how and when to use this book

What is an eco-home? What do you need to know to create one?.. 13

How to find what you need in this book ................. 14

Speed-reading ......................................................... 15

I. WHY ISSUES

2. Why have an eco-home?

Overarching reasons................................................ 17

What benefits do you seek?.................................... 17

Eco-purism or pragmatism ..................................... 18

II. WHERE ISSUES

3. Climatic and microclimatic considerations

Local climate basics ................................................ 21

Choosing what should be where in the garden: microclimatic landscaping.. 23

 

4. New-build: site choice and planning

Location basics........................................................ 29

Choosing an area..................................................... 30

Choosing a site ........................................................ 31

Choosing where the house should go .................... 32

Choosing to group homes....................................... 35

 

5. Choosing an old building to eco-upgrade

Old buildings basics ................................................ 39

Choosing an old house............................................ 40

Structural problems: cracks .................................... 41

Structural problems: rot and insect damage .......... 42

Sunlight .................................................................... 43

Relation to other homes .......................................... 43

III HOW ISSUES

6. Keeping warm: minimising fabric heat loss

Heat-loss basics......................................................47

Insulation .................................................................. 53

Building physics.......................................................56

Insulation materials..................................................59

Avoiding common insulation failures ......................62

 

7. Keeping warm: airtightness issues

Airtightness basics................................................... 66

PassivHaus .............................................................. 67

Dynamic insulation .................................................. 68

Airtight construction ................................................70

Ventilation control ................................................... 74

 

8. Keeping warm: heating

Heating basics .........................................................77

Heating ..................................................................... 78

What fuel to use: CO2 and design implications ...... 80

Thermal mass ..........................................................83

Solar heating............................................................86

 

9. Keeping dry

Dampness and dryness basics...............................91

Design for dryness...................................................94

Making an old building dry ......................................95

 

10. Keeping warm and dry: implications for different types of construction

Warm and dry walls .................................................99

Warm windows ......................................................105

Insulating roofs: different constructions for different types..108

Warm ground floors...............................................111

  

11. Keeping old buildings warm, cool and dry

Insulating old buildings: basics ............................. 115

Insulating old roofs ............................................... 117

Insulatingoldwalls ..................................................119

Upgrading old windows ........................................ 125

Insulating existing ground floors ........................... 127

Old chimneys: problems or assets? ..................... 129

 

12. Keeping cool

Cooling basics ....................................................... 132

Keeping heat out ................................................... 133

Keeping cool indoors............................................. 138

Keeping cool in an old building ............................. 142

Keeping cool outdoors .......................................... 144

Keeping homes warm and cool ............................ 146

 

13. Keeping healthy: physical aspects

Healthy building: physical/material basics............ 150

What we breathe.................................................... 151

Physical but non-sensible factors ......................... 154

Making an old building healthy ............................. 156

What we drink ........................................................ 157

What we eat ........................................................... 158

 

14. Keeping healthy: spirit and soul

Daylight and mood ................................................ 164

Spatial factors ........................................................ 165

Sensory nutrition.................................................... 170

Soul/spirit factors................................................... 173

Nature connection ................................................. 176

 

15. Keeping the home safe

Security basics ...................................................... 179

Burglar-proofing..................................................... 180

Making an old building secure .............................. 183

 

16. Whole-life access

Disabled access basics.........................................184

Physical accessibility ............................................. 185

Making an old building accessible........................189

Safety for the visually impaired ............................. 190

IV WHAT ISSUES

17. Minimising hidden environmental impacts

Environmental impacts basics .............................. 193

Materials we build with .......................................... 194

Things we use........................................................ 196

Things we get rid of ............................................... 197

Water recycling ...................................................... 197

Nutrient recycling................................................... 199

Construction waste reuse...................................... 201

Things we affect: biodiversity ................................ 202

 

18. Generating energy

Micro-energy generation basics............................ 207

Solar energy ........................................................... 208

Wind energy ........................................................... 211

Hydropower ........................................................... 213

Heat pumps ........................................................... 215

Combined heat and power.................................... 216

 

19. Sequence of action, and by whom?

Procedural basics .................................................. 219

Somebody else builds your house.......................... 221

You build your house ............................................. 223

You build your house with friends .......................... 226

You buy an old house and someone else improves it . 227

You improve an old house while living in it ........... 228

 

20. Eco-building and eco-renovation: learning and doing

 

APPENDICES

Appendix 1. Case Studies

Eco-home examples.............................................. 232

Review: Eco-homes’ appraisals and faults (what I should have done).. 242

 

Appendix 2. Glossary of technical terms

 

CHAPTER ONE

Introduction: why, where, when and how to

use this book

 

WHERE? (Microclimatic, social, connective and site planning issues) page xx

HOW? (Keeping warm, cool, dry, healthy and safe) page xx  

WHEN AND WHO? (How to, and who should, build; and in what sequence?) page xx

WHAT? (Minimising hidden environmental impacts, and generating energy) page xx

WHY? (What benefits do you seek?) page xx

 

What is an eco-home? What do you need to know to create one?

What is an eco-home? If you more or less know, and more or less know how to create one, you don’t need to read this book. Or perhaps you do. There may be things you haven’t thought about, or aspects of things that you haven’t considered in depth or didn’t know. Some might even be vital issues for how your house performs and lasts, and how it is to live in – and how long you live.

Everybody more or less knows what an eco-home is, but as there’s no official definition, nobody actually knows. Is it necessarily a house? Can it be a caravan, yurt or even a high-rise apartment? Is it a zero-carbon – or, better, a carbon-negative – house? (Glossary entries are shown in bold at their first occurance.) Would that include a wholly uninsulated house connected to a photovoltaic farm? Or is it a house so nature-friendly that it’s full of wasps, rats and (suspiciously ominous) mushrooms? Or should it be so zero-impact that living in it means dressing for outdoor temperatures? Everybody knows it doesn’t mean those sorts of things.

It’s safer, therefore, to focus on what everybody more or less knows: that it’s something to do with supporting ecological stability.

What is ecological stability, though? Climate stability is an absolutely essential part of this, but only a part. Preserving or recycling key resources (e.g. water, nutrients, perhaps manufacturing feedstocks) is comparably important, although this hasn’t yet reached a tipping-point crisis. So is the maintenance of a self-regulating ecology. This is mostly about reducing pollution, preserving biodiversity and, indirectly but crucially, food security. Common to all these, however, is living in harmony with nature. But can we do this if we live in town? As most of us do, for life to survive on our planet, this is absolutely essential: living in harmony with nature doesn’t mean living in nature.

Historically, however, the eco-architecture movement didn’t start very harmoniously. There were those who focussed on minimising energy use. Hermetically sealed buildings with tiny windows appealed to them. Others were principally concerned with occupant health. They liked air-permeable buildings, lots of fresh air and solely natural materials. Others again sought hi-tech solutions to everything. Some focussed on autonomous houses and self-sufficient lifestyles; others, on social issues – even to the point of collectivism. And everybody thought ‘ecology’ meant they couldn’t use their favourite materials or do anything artistic. Nobody ever considered the risk of dying from heatstroke, at least not in Britain: at that time, heat-retention (for resource-preservation) seemed the issue, not cooling (for survival). Climate change wasn’t a concern; oil-depletion (and related price-rise) was. Also, although some thought meditation could transcend ecological disaster as this is ‘merely’ material, nobody discussed the spiritual dimension of sustainability.

Fortunately, those days are behind us – but their echoes still remain. Few seem to realise that harmony with nature means embracing and synthesizing all of this. If we omit the material concerns, things don’t work. If we omit the aesthetic, we only serve the material side of nature and humanity. The climate crisis demonstrates this. If material solutions don’t work, human – and probably all – life won’t last. But if concentration on practical aspects ignores soul and spirit issues, life won’t be worth living – and (according to statistics) is likely to be shorter.1

Does this make what ‘everybody more or less knows’ unduly complicated? It shouldn’t. It just means that there are many more issues than energy conservation to attend to. In this book, I therefore first address the ‘why’ behind eco-home design: the overarching ‘mother issue’. Then follow ‘where’, ‘how’ and ‘what’ issues: the specifics. Further, to actually build or convert your home I also discuss the ‘when’ and ‘who’ issues: achieving its delivery.



How to find what you need in this book

This book is divided into six parts. These cover the reasons – and their design implications – for wanting to live in an eco-home; how to decide where it should be and remedy the shortcomings of your chosen location; how, in performance and constructional terms, to design a new eco-home or eco-upgrade an existing building; the things it affects and the energy it needs; how to do it; and how to get started and avoid mistakes.

WHY ISSUES helps you identify the particular benefits you’re aiming for. These are much more varied than most people, looking through their individualised lenses, suppose. They range from monetary to spiritual, personal to global. We may want them all, but different people have different priorities. This affects design.

WHERE ISSUES covers microclimatic, social, connective and space-use matters, and how these affect site planning. These also have much greater significance and scope for action than is generally supposed. ‘Where’ also applies to eco-renovation, but in a different way: you need to be able to evaluate problems that existing buildings have. All old buildings have some, but how easy are they to remedy? This is critical to your decision about what building to buy and eco-convert.

HOW ISSUES introduces you to how to get your home to do all those things you need it to: keep you warm, dry, cool, healthy and safe..Whether you’re building an entirely new eco-home or renovating a less-than-satisfactory old building, the basic physical and design principles are the same. Consequently, although chapters on old buildings deal with specific renovation issues and associated constraints, pitfalls and solutions, the bulk of every chapter is relevant for both. As there’s a huge variety of building types, construction and ages, and of climatic circumstances, this is the largest section of the book.

WHAT ISSUES covers hidden environmental impacts; recycling of water, waste and nutrients, and generating energy.

Finally, to actually build or convert your home, WHEN AND WHO ISSUES discusses how to proceed. Who will build it: you or a builder? What are the practical and sequence-related implications of your involvement? The final chapter helps you get going!

Before you start, I recommend you read the Case studies (Appendix 1). These give examples of eco-homes I have designed and what I’ve learnt from the mistakes I made. I suggest you read the descriptions in the first section (Eco-home examples) and test yourself to see if you can anticipate the mistakes described in Review: Eco-homes’ appraisals and faults (what I should have done).

Each chapter includes a list of resources (in alphabet- ical, not importance, order). These include further information on sustainable building issues, techniques and products. This, of course, can only be a partial list. For the products especially, there is a huge amount of information out there. For example, a complete list of all the (purportedly) ecological building products found at Ecobuild (the largest building trade exhibition in Britain), would fill several volumes. (Instead of this, just visit www.ecobuildproductsearch.co.uk/.) Moreover, new products, suppliers and publications are appearing all the time, so this list is unavoidably already incomplete and out of date. Consequently, I have limited the products and suppliers listed here to those less common ones that I have used or considered using. Many items are relevant across different chapters but, unless of particular importance to another chapter, aren’t repeated.

Unavoidably, this book contains some technical terms and concepts you may be unfamiliar with. I have included a glossary at the back of the book, so you can both understand these terms and have sufficient techno-speak to convince builders you understand enough about building so they can’t cheat you. (You don’t have to understand, and they may try to cheat – but it still helps.)

15

Speed-reading

The time for abstract theorising disappeared with the last century. Climate change is now an established fact and one that we have to find out how to live – indeed, to survive – with. We no longer have time to spare, so we need to know the practical ways of doing things. This book aims to help get you started. To speed understanding and highlight crucial practical issues, I include choice-tables, keypoint summaries and a large number of diagrams and illustrative examples. To further assist speed-reading, and to help navigate your way through the book, each part and each chapter starts with a diagram of the issues it covers.

To create an eco-home, it isn’t necessary to read the whole book. Just look at the sections you need to know more about. However, to create an eco-home that’s worth living in, I recommend you also look at the sections you think you don’t need. The topic, after all, is immense. Moreover, as every family is unique, every home (and every eco-home) will be unique. No one formula can ever fit all. Only you know your needs and preferences, and the unique location of your home gives unique opportunities. That’s why you need to start, not with fully formed answers, but by asking the right questions. This book, therefore, aims to give a brief and holistic overview, so that you can ask the questions right for your situation. The next step is what to do, then how to do it. I therefore include enough practical details and concrete examples so that you can find out most, perhaps all, of what you need to know, look in the right direction – and see through salesmen’s hype – if you want to know more.