In response to ordinances that restrict square footage or the percentage of a lot a home can take up, upscale home builders are adding luxurious spaces underground. Trophy basements do not expand the exterior footprint, so they also enable wealthy homeowners to preserve their lawn space and be more discreet about the size of their estates. Builders have taken steps to ensure these underground spaces do not look like basements, by giving them high ceilings and other luxury touches. Some even feature bowling alleys and other recreational amenities. The costs of building underground in areas like New York are 50 percent to 100 percent higher than gutting out an above-ground townhouse; but they are much lower than building above ground in Los Angeles and other areas, though the site’s geology plays a role as well. Meanwhile, municipalities like Malibu, Calif., have restricted underground building by eliminating walkout basements and counting more underground space toward allowable square footage. | Read More