Stack House was designed as a compact modular home that maximizes outdoor living space and is passively cooled with a thermal chimney that doubles as a refuge during a wildfire.The central staircase functions both a the primary vertical circulation and as a thermal chimney increasing the natural ventilation through the different living spaces.The composition of the building mass and window openings negotiate tight zoning envelope constraints and the limitations of pre-fab construction. Leong Leong collaborated with a local developer in Los Angeles to design several modular homes in Mount Washington. The development thesis proposed building on exceptionally steep sites which would require extensive poured-in-place concrete foundations. The cost of this construction is offset by building custom pre-fab modular units.