Actual-Size Architecture, a San Francisco bay area residential design
Bridgwater Addition

For this unbuilt project, the owners of the original turn of the century, shingled home wanted to expand the unfinished ground floor, and add on to the rear without losing the house’s gabled character.



Using solar-heated radiant tubes in the floors was important, firstly because of the cost of heating in the house's cold, wind-swept location, and secondly due to the owners’ aversion to the sound of forced-air furnaces.

The roofs of the addition are rotated ninety degrees from the house’s existing ridge to face due south. The pitch of the south-facing sides were specified by a solar consultant to be 45° for the proper balance of domestic water and radiant heating for this location and usage. The north-facing sides are pitched at 29° so as not to cast shadows on solar collectors of adjacent roofs, even during winter solstice.

Sandwiched roof construction of batt and rigid insulations is configured to be fully vented, while allowing cathedral-ceilinged spaces below. Structural tie rods over the kitchen keep roof forces in check, and a system of cable lights they hold in tension mirror the pitches of the roofs above.
In the dining room, a skylight running the length between the north-facing roof and a pitched, south-facing wall forms a type of year-long solar clock as the sun cycles from solstice to solstice. Laminated bamboo panels in the ceilings of the south-facing roofs express the structural module while echoing the solar collectors above.