It’s a dream of mine to build my own eco-home. I’d love to live in a beautiful, guilt-free house that’s cosy in winter, cool in the summer, and super energy efficient. I chafe at having to make do with the conventional when I could design something that’s perfect for the way I want to live. Plus, it would be amazing to look around my home and think, ‘I made this’. Or helped, at least.
I’m nowhere near being able to start a project like this, but I’ve been reading up, and I now know what I’d like to build, and why. I thought I’d share some of what I’ve learned so far, and review the books I have.
Here are some of the key points for me:
- The denser the material, the more thermal mass – therefore the better it is at absorbing and slowly releasing heat. Thermal mass is key when building in a climate with extreme daily temperature variations.
- The more air in a material, the better its insulation value.
- For a given thickness of wall, you get more of one property at the expense of the other.
- Of the materials I’ve been looking at, cob has the most thermal mass, straw the best insulation, and cordwood is in between.
- Passive solar design includes the strategic sizing and placement of windows and the use of materials and colours which either absorb or reflect heat.
- Cob is the most flexible material – you can literally build any shape you want with it. It is also the most time-intensive by far.
- Strawbale and cordwood are less flexible, but you can still build curved walls and make doors and windows in any shape.
- All can be finished with earth plaster, giving the same beautiful look as cob.
Let me tell you about the house I have in my head. I live in Scotland, with long winters and below freezing temperatures, and warm, often rainy summers, so insulation is top priority. My imaginary house is earth-sheltered, built into a southwest-facing hill, with a longer exposed wall to the southwest. The southwest wall is cordwood, which is relatively quick to build and has a good balance of insulation and thermal mass.
There is a greenhouse built against it – the greenhouse helps insulate the house, and the house helps regulate the temperature in the greenhouse. And it is full of beautiful growing things.
I’m still debating about the roof, but I think it has a slightly conical green roof, accessible from the earth-sheltered back, and with solar panels facing the sun at the front. The center (right now) is a load-bearing oval skylight – big enough for two people to sit on and watch the world. Not sure if that is entirely practical, but it would be amazing.
Building Green: A Complete How-to Guide to Alternative Building Methods by Clarke Snell and Tim Callahan
I got this after a lot of browsing. It’s a phone book-sized tome which proved to be surprisingly readable – my partner and I have both read it cover to cover. It’s written by two men: a master craftsman and former conventional building contractor, and an experienced eco-builder. One of my favourite things about this book is it’s honesty. They don’t sugar coat it -they’re open about the down-sides, not afraid to tell you which bits were a pain in the arse, and willing to be objective regarding the merits of alternative vs. conventional methods.
They actually built a tiny house for the book, using different materials for each wall, and with a green roof. It covers everything from theory to leveling the site and laying foundations to putting up shelves, and lots of nice aesthetic touches too. It has pictures of every stage of the build, and talks you through the whole process – including how long everything really took. At the end, they tested each wall separately for heat-loss to compare performance. Best of all, they tell you exactly how to do it yourself.
There is a lot more in the book, but it would take an entire blog post to mention it all.
Bottom line: I now know more than enough to create an intelligent, functional design to suit my climate and needs. If I had to, I could probably build a house using this book alone, although in reality I plan to read more and go to relevant workshops, and would consult an architect before starting a build.
These aren’t how-to books, they are daydream fodder. They are both collections of pictures of tiny houses and cabins with short descriptions. They were a bit of an indulgence, but I love them and I hope that I’ll be able to justify them someday when I’m needing inspiration for real.
Cabins: A Guide to Building Your Own Nature Retreat by David Stiles
I obtained this one by chance. It isn’t about alternative building, it’s a manual of conventional building techniques including log cabin construction and a variety of timber frame options. If I could only have one book, it definitely wouldn’t be this one, but it’s interesting to get a conventional perspective on cabin building, and I think some of the techniques will come in handy if I ever do get a chance to build.
Please share if you’ve read anything on this subject – I’m always looking for more books, and there’s a baffling range of them out there!
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