Lyrical Sustainable Design- a cabin by Rob Harrison
It's summer,and we hope that many are able to get away to a place in the woods or by a lake for a while. We will try to profile a few of the more interesting retreats we have found over the next few weeks.
Seattle Architect Rob Harrison's practice is based "on principles of "lyrical sustainable design" - conserving energy and resources; using healthier materials and finishes; reducing long-term costs; and making poetic places. We emphasize the functional, aesthetic and sustainable aspects of design equally."
We like a lot about his Chiwawa River cabin. First of all, the honesty: "It could very easily be argued that no one needs a second home...and therefore it is impossible to make a second home "green." But there are other considerations - the heuristic value for example. In our client's words: "It's more than a summer place it's the opportunity to get to know a place through the seasons and the years, to have a chance to steward a small piece of the earth, to be connected to a place which is woven with the strands of the lives of family and friends."
Now that we have second home guilt out of the way, the decisions and choices that have been made are reasonable, balanced and realistic. For example this treehugger has often struggled with how to heat a cabin- one does not want to invest in a big infrastructure of furnaces and ductwork when the place is heated for a few weekends per winter, and one wants to maximize individual control. The words "electric baseboard heat" rarely pass the lips of designers involved in sustainable design, but it makes sense and Rob faces it head-on. I feel less guilty knowing that I am not alone.
* building site chosen to minimize impact on wetland and steep slope, including least new paving for driveway
* all new paving will be pervious "Grass-Pave" or semi-pervious gravel
* compact two-story design minimizes footprint
* specifications call for extensive mitigation of effects of construction, native planting, replanting trees, removal of existing old fire road, etc.
* the site will have higher ecological quality when construction is finished than it has currently
* sun-tempered design (actually works east of the passes...)
* low-slope roof will retain snow, adding insulation in winter (We analyzed wood use in high and low-pitch roofs, and determined that even with beefing up of structure required the low slope option saved wood as well as increased energy-efficiency.)
* structural insulated panels provide tight envelope and quick close-in in this area with a short construction season
* electric baseboard heat chosen because of low cost and ability to individually control temperature of rooms
* high-efficiency wood (biomass) stove for supplemental heat
* high quality low-e, argon-filled double glazed windows
* full line jobsite recycling
* advanced framing techniques applied to SIPs (also allows quick switch to stick framing without redesign if contractor finds SIPs exceed budget)
* source reduction through...compact design
* recycled-content composition roofing
* kitchen and bath cabinets will be reclaimed
* smooth HardiPanel fiber-cement siding (ripped into two 24x96 sheets, used as overscale lap siding)
* Ironwood (from well-managed source) used for exterior decking and trim
A Healthier Life
* low-toxic paints and finishes are specified
* finishes eliminated where possible eg. Ironwood
We Could Have Done Better if We Had
* more experience with and better access to composting toilet and graywater systems. Although they were interested, our clients had concerns about how well a composting system would handle intermittent use. Our and the contractor's lack of experience with these systems and difficulty finding existing homes that use them to see how they work out in practice led our clients back to a conventional system.
* additional studs and hold-downs between panels because of the snow load suggests that SIPs aren't saving us as much wood as we'd hoped.
There are not many architects in this world who could pass the words "We Could Have Done Better if We Had..." Nice work, Rob.
::Robert Harrison Architect and he blogs at ::lyrical sustainable design