Christopher Day is a veteran of the world of architecture in Britain. In his new book, The Eco-Home Design Guide: Principles and practice for new-build and retrofit, he has condensed his considerable experience of both designing and hands-on building into a set of guiding principles for how to go about your own ecological building project.
The book is well organized into primary divisions that deal with the major issues that confront anyone who undertakes such a journey. These what, where, how and when issues are each examined in turn, so that by the time you complete the book, you should have a good understanding of all of the issues that need to be addressed. Each chapter is summarized at the end with a listing of the key points covered and a chart of the main choices that need to be made. With this approach, you can quickly thumb through the book to review the basic information presented.
The Why section presents the overarching reasons for engaging in an eco-build in the first place. These reasons include lifetime economy, thermal comfort, minimizing dependence on outside sources of energy, helping to mitigate climate change, creating a healthy interior environment, and soul nourishment.
The Where section looks at the physical site and the impact of its microclimate on the building. For a newly built home, strategies for both increasing and decreasing the influence of wind on the house are evaluated. How to naturally retain heat during the winter or keep the space cool during the summer are outlined. Factors to consider that would affect the cost of living and the value of the house over time are discussed. How is the gardening potential at the site? How do you optimize privacy, light and views? I was pleased to read that Christopher advocates seriously considering the benefits of clustering houses to take advantage of small community amenities, such as a shared children’s play area, storage facilities, and other equipment.
When evaluating an older home that might be renovated, does its construction lend itself to the improvements you have in mind? Are structural faults of the sort that can be repaired or they likely to be ongoing problems? Does the place smell bad? Is it oriented properly for solar heating? What is the gardening potential? Is the house and neighborhood safe?
The How section of the book constitutes 60% of the content and is primarily concerned with the indoor climate: how to keep your house warm or cool, depending on the season, and dry. The science of thermal dynamics is presented. How does a building lose its heat? Here the value of a smaller, more compact space is stressed. How much insulation is necessary and what types of insulation material is best? How do you avoid insulation failures?
How airtight should your house be, and does this affect your health? The European PassivHaus standards are evaluated. The concept of “dynamic insulation” was new to me, and is an interesting approach to keeping the air fresh without losing heat.
What kinds of heat are the most comfortable and efficient? What are the ecological effects of various fuel choices? What is thermal mass, and how can it best be utilized? What are the basics of solar heating?
In terms of building health, the dynamics of moisture control is paramount. This is a complex and technical aspect of building science that takes some real study to understand. Humid air can condense in areas that would compromise the life of the building and the occupant’s health. How do you go about assuring that this doesn’t happen?
What are the benefits of various common building materials? Some of the information in this chapter pertains more to those materials that are available in Europe. How can you keep from losing too much heat from your windows, roofs and floors? Strategies for retrofitting old buildings are specifically addressed.
Some of the same things that help keep buildings warm will also help keep them cool. Other specific approaches to cooling are defined and are often focused on air movement.
How do we assure that the indoor environment is non-toxic? This generally involves making wise choices for building materials, but also includes the water we drink, and the food that we eat. Should your house include a greenhouse for growing food?
As the author of Places of the Soul (1990), Christopher Day could not avoid discussing how to keep your spirit and soul healthy. He talks about the effect of daylight on your mood and how both space and coziness are important. How do we maintain our connection with nature?
Another factor that is not often associated with ecological construction is the question of safety, in terms of security from burglars in particular. Also, how do you make a house accessible for disabled people, so that the house is accessible for the whole of life?
The section devoted to What issues deals mainly with the hidden environmental impacts of various building materials, lighting choices, and approaches to recycling water and organic waste. How do we enhance biodiversity? What are the pros and cons related to various methods of generating renewable energy? Solar power, wind energy, hydropower, heat pumps and combined heat and power units are all considered.
The final section deals with When, in terms of building sequences and choices for self-building or hiring a contractor. Can you live in a space while renovating it?
The book concludes with a short survey of several building projects that the author has been involved with, and he talks about how he might approach them differently now.
All in all, I feel that this book is quite worthwhile. The author certainly understands the basics of ecological design and construction and does a good job of introducing you to most of the issues involved and choices that need to be made. His perspective is distinctly British and some of the terminology and products mentioned will not be familiar to the American audience. It is well illustrated with many sketches mostly drawn by the author.