“What’s An Eco-Shed?”
April 16, 2008
No, really, what is it? Where is it and how does it work? Good questions, all. Here’s the full scoop on my “new model home in miniature.”
OK, I’ve been on sabbatical in Ghana for the past two years. What’s the Eco-Shed?
It’s a 260-square-foot sustainably designed writing studio and overnight guest suite that I’ve been building in my front yard since early 2007. It’s essentially one big room with a built-in desk, kitchenette area, and small 3/4 bath.
What’s the deal with the book?
In Canada, it will come out August 22 and the title is ALMOST GREEN: How I Built an Eco-Shed, Ditched my SUV, Alienated the Inlaws, and Changed my Life Forever (Greystone). Meanwhile, my American pals will get it September 9, and there the book will be called ALMOST GREEN: How I Saved 1/6th of a Billionth of the Planet (Skyhorse/Norton).
What makes the Eco-Shed green?
- Passive solar design, which is actually sort of pointless, given that it rains on Bowen Island just about every day between October and April. But on those cold-season days when ol’ sol does decide to shine on my little corner of crust, the Eco-Shed is designed to soak up and retain the heat.
- Ventilation system delivers constant supply of fresh filtered outside air.
- Better-than-code insulation in combination with a double-framed north wall. A double wall eliminates the “thermal bridge” that lets heat “wick” through two-by-six walls.
- Electrically-fired hot water on demand system for shower and sink.
- All framing and 98 percent of the finishing lumber is either reclaimed or certified by the Forest Stewardship Council. Essentially, “FSC” means the trees were harvested from responsibly managed forests. The P5140020roof joists were remilled from giant timbers that supported a logging-railroad trestle in the Comox Valley on Vancouver Island, BC. The roof decking supported the second floor of a dry-goods store that was dismantled in the Fraser Valley east of Vancouver. The clear-grain cedar siding was mostly re-milled from pilings and timbers that originated in log-booming grounds near the mouth of the Fraser River. Finally, the framing lumber itself is spruce, harvested from FSC forestlands managed by Tembec.
- High-fly-ash concrete. This means that the concrete poured for the studio’s foundation contained a high proportion of fly ash, which is in turn made from the incinerated remains of ground-up flies and other insects. Actually, that’s not true. The gunk is a waste product that is scrubbed from the stacks of coal-fired power plants, and used, in this case, to displace portland cement from concrete mix. The less portland cement we use in our concrete, the bettter, because cement is made in kilns fired with tonnes of coal. (And no, I don’t mean “clean” coal…)
- We have a rainwater harvesting system; water landing on the Eco-Shed’s roof ends up in a gigantic plastic cistern I call the Tankosaurus. It’s under our main home’s deck to the east. From there, it will feed our edible garden. The raised garden beds were built with island-sourced stone, and the deer fence was split from mostly beach-harvested cedar. (The guy who built it collects cedar logs off the Bowen Island shoreline by canoe.)
- About a dozen other things that I will add here when I remember them.
Why did you build it? Wouldn’t the greenest choice be to build nothing at all?
The truth is, I’ve always been a closet architect, and I wanted to create a kind of a miniature-scale “new model home” to teach myself how sustainable buildings actually get that way, and also find out if it P6100005would be possible for a middle-class family to build green without spending a fortune. Plus, we already had the foundation in the front yard. When our tract home was built in 2005, we asked the builder to pour the concrete slab for a future studio that would serve as an overnight guest suite and home office. We spent two years staring at that foundation, and one day, we got the idea that it represented an opportunity–to break out of the mold, to do what should’ve been done with our main house in the first place. Our bank was happy to loan us the rope we needed to hang ourselves with.
How much did you involve yourself in the design and construction?
The Eco-Shed was truly a team effort: I served as general contractor, grunt worker, researcher, and details man; Bowen Island-based architect Dan Parke (Salal Architecture) designed the building, tolerating a great many tweaks and annoying questions from my end all the way through. Finish carpenter Jeremy Galpin actually swung the hammer, with help from me lifting rafters, planing siding, denailing and sanding reclaimed wood, and so on.
Why didn’t you built it with straw/rammed earth/cob/hemp? That’s a far more sustainable material/approach!
Yup, we greenies sure feel passionate about their straw/cob/hemp, etc. We went with recycled and certified wood for reasons of site suitability, cost, and localism. We had on the site an existing 14 x 20 foundation pad to work with–originally designed for a stick-frame building–that we wanted to use. It is a bit of a tight footprint, and we had to rearrange some other pieces of the puzzle to make it work. (This is where the “alienating the inlaws” bit comes in…) Straw works best at a bigger scale, and even though there are two straw-bale buildings on my island, I concluded that the material is perhaps better suited to drier, interior climates. If we were starting today with a blank slate and without any limitations of cost or site, I personally believe insulated rammed earth is probably the best building system for Howe Sound. That said, it remains well beyond the price range of most, including me. Problem is, you can only justify the cost of rammed earth for larger structures. Ours was too small to make it work.
What did it cost?
So far, about CAD$85,000. You can do the math yourself on a per-square-foot figure, but the result will not be a useful number because the building is so small. Such calculations make sense when we’re talking about large homes, and the Eco-Shed afforded us no “economies of scale.” For example, the ventilation system we installed will cost the same as one designed for a 2,000-square-foot home.
OK, so how much more than a “standard” studio is that?
It’s roughly twice the circa late-2004 estimated cost of the studio that was originally drawn up for the site by the design-builder who did our house. But the figure doesn’t include life-cycle costs. This is getting to be a bit of a chestnut, but it’s the central conundrum of green buildings and my book. Like organic groceries, green costs more at the outset–for a very complex set of reasons having to do with subsidized oil and other delightful realities–and saves you in the long run. The project has gone absurdly over budget, but still feels worth every penny. It will probably pay for itself in, um, around 2076… give or take a decade….
What was the hardest part?
Paying for it. (Still working on this!)
What would you have done differently?
A number of complicated, specific, small things that impact the overall energy performance of the space. Example: I might have reconsidered the insulation scheme–we went with a spray-in-place Icynene foam insulationfoam, which has terrific air-sealing qualities, but carries both financial and ecological burdens. Our wood stove doesn’t have a connection on a damper to fresh makeup air, which means that code required us to punch a six-inch-diameter hole in our otherwise totally-bomber building envelope to provide replacement combustion air. These missteps would likely have been avoided with an integrated design process. We wanted to take this approach for the Eco-Shed, but couldn’t convince anyone to show up for the meetings. Our project is tiny, and the folks who should have been there from the word go–like our mechanicals guy, our electrician, our building inspector–were all way, way, way, way, way, too occupied with far more lucrative projects than mine. There just wasn’t enough in it for them to give up an hour or two of work time in one of the hottest construction markets in Canadian history. So we did our best to anticipate goofs, but hey, no biggies have emerged yet. We’ve done pretty well. This is cutting edge stuff here!
Are you applying for LEED certification or BuiltGreen?
No. The Canada and U.S. Green Building Council’s LEED system is a terrific program that is driving a lot of innovation, but it’s not appropriate for what we’ve done. We’d spend almost as much getting the supporting documentation just to apply as we have on the whole building. That said, I did sit down and add up the points that we would have scored had we applied under the LEED Homes program; we end up around a theoretical gold level.
Where Does the Project Stand Today?
The book is finished; look for it in Canada toward the end of August and in the U.S. in September. It’s hilarious! Just like me! Honest! The Eco-Shed, on the other hand, though sealed up and sexy-looking, is still not quite ready for its close-up. We emptied our piggybank, and still need a few things wrapped up, like, er, tile, bathroom fixtures, ventilation system, boiler for in-slab hydronic heat, millwork, trim, final electrical… Anyone got a spare $15,000 kicking around? How about corporate sponsors? The “B.C. Hydro PowerSmart Eco-Shed,” anyone? How about the “Lululemon Eco-Studio”…? Anyone? Hello?
Why did you do [xxx] with [yyy?] Don’t you understand that [insert situation] is going to [wildly speculative forecast of world events]?
Good one! If you’ve been harboring this or any other infrequently asked questions, don’t be shy. Go ahead, ask them via [james at glave dot com], and I will be happy to fill you in and share the answer here. Unless it’s about my inlaws and how I alienated them… I’m still not talking about that. You’ll all have to wait for the book. Sorry.
