The green roof is in at Zero Cottage. It’s actually a brown roof, a desert to survive with minimal irrigation. David Fletcher’s design has a shifting color pallet of succulents. The soil areas of the roof are maintained and stabilized with motorcycle tires, including one from a Harley Hog.
There was so much salvage maple flooring from the Tassafaronga Village Pasta Factory that after using it for the two living level floors we still had a big pile.
About this time I became aware of the Japanese (and Finnish) practice of finishing exterior wood by charring. This produces a beautiful deep black finish that is quite durable and very wabi sabi. The traditional reasons for charring are to provide a durable layer of carbon for weather protection and for fire resistance. In Japan they make a three sided chimney out of wide cedar boards and set that on a charcoal brazier. Flamed shoot out the top. We used a roofing torch to char the boards.
They are screwed to vertical cedar battens to form a low tech rainscreen.
The solar canopy that will hold the 16 photovoltaic solar collectors is in the final fabrication stage. The canopy will be elevated from 3 to 6 feet above the roof, and cantilevered over the edge, to shelter the entry stairway and door. This will be a 3 KV system, large enough to generate more energy than the Zero Cottage uses over the course of a year, making this a true on-site regenerative, or Net Zero, structure.
Henry Defauw of defauwdesign has developed the design concept into the CAD shop drawings from which each unique piece is cut by a computer driven waterjet cutting machine. I’ve worked with Henry for many years, since he was a fabricator at the legendary Sand Studio (formerly South Park Fabricators).
Installation is scheduled right after the parts come back from galvanizer in early August. The solar contractor Luminalt will then attach the semi transparent glass backed Sanyo collectors. The inverter and internal wiring are all installed and ready for the collectors to complete the system.
The exterior siding systems are now finished!
The FALCONFIVE crew have done a great job building Zero Cottage. Both Passive House construction and building in a tight urban location are complicated and demanding and Jon Blandin’s team has been up to the task. www.FALCONFIVE.com
This morning was the first scaffold-free day revealing the west-facing metal rainscreen wall. The shingles are cut from scrap from Zahner, sheet metal fabricators to the starchitects, new material, and some odds and ends, such as the road sign I bought at a the Alameda Flea Market. The stainless steel clip system we designed and micro-manufactured allows any tile to be swapped easily with no tools. I’ll do a post detailing exactly how we built this soon.
In preparation for adding the final layer of exterior finish material we screwed cedar battens through the 2” layer of foam into the plywood sheathing. The theory is that the Grace Perm-A-Barrier water/vapor barrier will stop any moisture from getting through to the plywood. The battens serve a couple of purposes: they provide a robust 3/4” vented space so any water outside of the waterproofing barrier can dry out. Also the foam is very weak in compression so aligning the clips for the metal rainscreen would be difficult.
The foam insulation board in covered with GreenGuard RainDrop house wrap. This is a robust building paper that has built in micro drainage channels to provide a passage for any water that might get behind it to migrate down and out.