Cistern House

The roofs are the design. Five separate planes, each pitched at a different angle, each draining to a copper channel that runs down the outside of the building in plain sight and terminates in a cistern under the rear court. Nothing is concealed. You can trace a raindrop from the ridge to storage without leaving the terrace. Total collection is about fifty thousand gallons a season, which covers roughly seventy percent of the household's annual demand. The cistern feeds through a sand filter into a header tank on the roof, and the overflow recharges a well that had gone dry in 2016 and is now yielding again. The copper was specified in mill finish and left to weather. It arrived bright pink, went brown within a year, and is now beginning to green on the north face where it stays damp longest. The architects photographed this monthly through the first two years. Inside, the multiple roof planes produce a set of rooms with genuinely different ceiling geometries, which does more for the character of the house than any amount of finish would. The primary bedroom sits under the steepest pitch and is nearly sixteen feet at the ridge. Topanga lots of this size come up perhaps twice a year. This one has a mature sycamore on the south boundary that shades the entire rear court from June through September.