Most homeowners who want to maximize living space add a second or third floor. In beach cities with strict restrictions on the height of homes, however, residents and architects are building down. Basements not only yield bigger homes, but also draw less attention from the street and fewer sneers from neighbors tired of maxed-out mansions.
The trend is particularly strong in San Diego County, whose coastal communities have some of the most expensive land in the state. This view of Stefan Lemperle’s La Jolla house offers few clues of the surprise that awaits below ground.
The modern basement: La Jolla house adds space by building down instead of up - builddown - Los Angeles Times