This house looks like it is being built with Lego blocks. Located by the stairs connecting Primrose (lower) with Primrose (upper) and Upper Lorne Place, the infill lot is about eight feet above the Primrose street level.
The house will be four stories high. The bottom floor, two stories down from Upper Lorne but “at grade” at Primrose, with be a studio — bedroom, room, kitchenette, bath — with its own exit on the Primrose side. The second floor will be bedrooms. The third floor, to be at grade with Lorne Street, will have the entry and a garage (yup, you park your car above the master bedroom). Up one floor will be smaller-area fourth floor (four as measured from Primrose, but only two up from Upper Lorne) with a generous roof top deck.
The building blocks are made of white foam, with plastic spacers that link the usual metal rebars. The hollow space is then filled with concrete, making a well-insulated wall. Another advantage is speed of assembly, which is important as winter comes on. Another factor is the lightweight materials can be carried (tossed?) around the site that would be difficult to manoever dimensional lumber and is inaccessable to mechanical lifters. The first floor shown was assembled in one day. The next day: the concrete was pumped in.
This is a closeup of the lego wall meeting the concrete footing. Nailed-on wood strips keep the blocks from “spreading out” and in line. The fabric wrapped pipe at the base will be the drainage tile. The blocks bulge out at this section to form a concrete lip or ledge to support the stone facade that will be installed later. And yes, it is green painters tape holding some bits together until the concrete is poured.
View from the ped staircase into the gap between the house and the cliff. The house foundation will not touch the cliff face, at city request, to “preserve” the cliff. The window on the cliff side will let in some filtered light, much like windows on side walls of houses that are located close together. Once the concrete is pumped into the form, it will become the load-bearing structure and bond to the foam insulation. The heavy vertical steel boards shown on the inside back wall are temporary stabilizers until the concrete is poured. The smaller vertical black lines all over the wall are bits of the plastic reinforcements from the concrete side of the wall, that extend through the plastic foam, onto which the drywall will be screwed. Before that, wiring will be run in channels cut in the foam with a wide saw blade, then the wiring will be covered up with spray on foam. No air leakage along the cabling …
Special hangers were installed around the inside perimeter of the wall, connected to the concrete, and a wood ledger beam was hung around the inside perimeter. Manufactured joists were installed in just a few hours. The joists are made up with a zig-zag pattern of wood struts, so no drilling is required to run wiring, ducts, or water pipes, which saves hugely on labour. Look carefully a at the stairwell hole in the foreground to see the joists under the plywood subfloor. The lumber in a house is only about 20% of the house cost. Much more is spent on labour and getting city approvals. In the above photo, the second floor walls are now half way up.
The second floor as seen from the Primrose stairs. Notice that another bulb-out has been installed along the left wall to form a ledge to support the stone facade.