This is a “pop-the-top off” remodel on a very tight urban site in a dense residential neighborhood, where expansion schemes force hard choices.  The gabled, century old archetype uses just half of the building footprint within the attic.  The clients wanted to capitalize on maximum possible area within the existing plan, without raising the ridge. They liked the idea of building a roof deck as a feature outdoor amenity, offering stunning views of the neighborhood.  There was another challenge: the top floor bathroom had been remodeled a year earlier, so it was to be kept intact, while the rest of the floor and roof around it was being dismantled.
The parti blended together remnants of the existing roof geometry, a shed dormer on one side, and a mansard roof on the other.  The envelope was crafted to stay at or under the existing roof line, with the street elevation reflecting the house’s original form.
In addition to the added interior space, transforming the top floor into a master suite, entertainment zone and an office, a cantilevered balcony was added to the south, featuring a bespoke digitally fabricated helical stair to the roof terrace above.  The stair was designed and refined in a series of scaled models, digital analyses and a full-scale mockup.  It was completely assembled off-site, then lifted and installed over a few hours.