The green roof garden was the last of three phases of work at this San Francisco home. The first phase in 2001-02 included a ground floor extension into the rear yard - which became the canvas for the rooftop garden in 2011-12 (see "Noe Valley Remodel"). Beside bringing the garden UP to upper floor living spaces to be enjoyed, a roof garden accomplishes several things: superior thermal insulation for the room below, water conservation (due to drought tolerant plant choices and water catchment possibilities), increased oxygen levels and air purification (which is good for the inhabitants AND the environment!), as well as returning urban infill back to green space (which reduces the heat island effect). A win-win for all!