Build up when you can?t build back Townhouses are metropolitan areas? answers to standalone homes (for those fortunate enough to live in one, of course), and though they are larger than most city apartments, they?re still on the narrow side.
To increase interior square footage, many homeowners add a rear extension?prevalent in London?and some even build up.
The latter was the solution for this 19th century brick row house in Toronto, Canada. Strict zoning regulations dictated its design, so local firm Aleph-Bau created a compact volume clad in corrugated aluminum that was barely visible from the street. A portion of it cantilevers over the backyard and is propped up by steel supports.
The residence now measures 1,227 square feet and encompasses three floors (including the addition). Common spaces are located on the first floor, while the master suite, a bedroom, and a balcony are placed on the floor above. Within the new third-floor extension are a bedroom and library. A basement level incorporates another bedroom, as well as a concrete entertainment room with built-in seating. The renovation also gave the home?s brick facade a new whitewash and imbued its interiors with clean, sparse details, natural elements like plywood and ample glass to let in natural light, and a zig-zagging central staircase made of steel painted turquoise on the lower level, white in the middle, and grey at the top.

A portion of the addition extends over th...