Originally proposed as a gallery extension to the home below, the rooftop program presented multiple complications. The penthouse is affected by strict zoning that limits modifications to the locations of existing exterior walls. The existing layout consisted of tight, double loaded corridors with minimal openings, leaving residents uneasy when entering the rooms on either side. In order to create a more comfortable spatial configuration, the architects designed a system of “habitable bubbles.” By covering and breaking the existing outer walls, and replacing them with extensive glazing that curves seamlessly around corners, the architects blur the boundaries between inside and out and provide panoramic views of the valley beyond. Each bubble houses a different use – dining, living, sleeping and toilets.