San Francisco–based lighting designer Terry Ohm’s prefab in the Northern California town Clearlake is an exercise in proportions. An 800-square-foot version of Taalman Koch Architecture’s iT House, Ohm’s residence features glass walls and an extruded aluminum frame. “The critical things in all of its spaces, and mostly in the kitchen, are function and scale,” Ohm says. His guiding principle was to design everything to be visually simple, from the materials to the proportions. The smallest appliance width Ohm could find was 24 inches, so he used that measurement as a baseline for the cabinetry, island, and work-space around the sink. With the help of furniture maker David Pierce, Ohm then designed the casework using Monterey cypress for the cabinets and island. He opted for Squak Mountain Stone for the countertops because of its matte finish. By balancing the light from a variety of sources and ensuring that every corner was illuminated, Ohm increased the feeling of expansiveness in the 12-and-a-half-by-14-foot kitchen. Ohm installed 50-watt MR16 halogen bulbs in cylindrical fixtures over the kitchen island and used linear spread lenses to direct the beams across the room. He then positioned LED strips along the back edges of the open shelving above the sink creating a perimeter of brightness. “If you only illuminate the center and have dark corners, the room starts to feel like a cave,” he says. As a bonus, the light softens the glass-and-steel interior.