Lot's second house is a charm

Infill house: 1,065 square feet, including garage

Density is no longer a dirty word in some communities looking for ways to use land more efficiently. Where regulations allow, they create new building sites by "infilling" - that is, by subdividing large lots with existing homes, creating rear or side parcels where a smaller house can be added. One particularly thoughtful and cost-effective infill structure is this 1,065-square-foot home designed by San Mateo, California, architect Ellis A. Schoichet for a client who decided to rent out her larger house at the front of the lot and live in a new structure at the rear.

A V-shaped "butterfly" roof and carefully placed windows give the tiny structure both surprising airiness and a sense of privacy. Its attached garage doubles as a studio for its artist owner.

Schoichet used ordinary materials in innovative ways. For example, the core of the house - which combines living and dining areas - is unified by a floor of bevel-edged 24-inch-squares of medium-density fiberboard that have been painted and stained to look like terra-cotta tiles. Exposed beams draw the eye upward to accentuate the feeling of loftiness. At one corner, a small kitchen opens to the main area; from another corner, a tiny hall leads to the bedroom and bath. Shojis turn part of the bedroom into a wall of closets. The bedroom floor is made of red-painted plywood, a vivid accent that also saved money.

Plywood exterior siding and ready-made windows kept costs under $120 per square foot.

Design: EASA Architecture, San Mateo, CA (650/343-3452)