SAN FRANCISCO (Map, News) - In San Francisco, it’s essential to get the most use out of the least space. After all, with some 750,000 of us packed into 49 square miles, there is no room for waste.

Architect Donald MacDonald has spent his career trying to solve the riddle of density. His solution, demonstrated in his two small 1980s San Francisco townhouse developments: Live simply, build vertically, and insist that rooms serve multiple purposes.

In 1983, MacDonald created a group of four townhouses on Herrmann Street, in the Lower Haight. He followed that up in 1985 with a compound of 10 homes at 170 Guerrero. One of the latter is now on the market for $670,000, listed by Tasneem Karimbhai of Hill & Company.

MacDonald’s mission was to create “small but beautiful” urban homes, so his creations are long on pragmatism and short on adornment. At less than 1,000 square feet, 170 Guerrero depends on its owners’ abilities to function in small personal spaces and shared public ones.

MacDonald put two bedrooms downstairs, leaving the upstairs — with its vaulted ceilings and large windows — as a multiuse living space that includes living, dining, kitchen and bath rooms. A recent remodel brought interesting materials into Unit I. The kitchen area has a glass tile backsplash, and the living area boasts a cork floor.

MacDonald’s urban living solutions are not for everyone. Some find his philosophy too austere and his designs too plain, while others may prefer — for the same money — to cram themselves into a traditional Victorian flat.

There is sense and beauty to MacDonald’s townhouses. Vaulted ceilings, large windows and skylights give his homes openness seldom available in urban, sub-1,000 square foot condominiums.

As 170 Guerrero, Unit I shows, MacDonald put plenty of thought and purpose into his “small but beautiful” designs.

Where: San Francisco

Asking Price: $670,000

Property Tax: $8,710*

The Property: Two bedrooms, one bathroom plus additional loft space; one of 10 townhouses in hidden Mission Dolores compound; bathrooms remodeled, new appliances in kitchen.

Notable: Donald MacDonald-designed, designer-decorated, forward-thinking approach to urban living, unique layout with unusual use of space.

Agent: Tasneem Karimbhai, Hill & Co., (415) 824-1100.

*Estimate based on 1.3% of asking price.

lrosen@examiner.com