The scheme in East Finchley was originally 'laughed at' by the local planning committee, despite gaining preplanning guidance from planners.
The project attracted 20 letters of objection from residents in the neighbouring tenement block although, partner Will Foster said, 'only four flats are actually capable of seeing the building'.
Despite the opposition, the appeal inspector granted planning permission, claiming the design would be 'appropriate behind the unremarkable rear elevation of the Sherwood Hall block'.
The development is on a sensitive backland brownfield site, replacing one garage and two derelict brick air-raid shelters.
The scheme's two two-bedroom apartments are arranged over a single-storey design, with a total floor area of 157m 2and 63 m 2of private gardens.
The project will use photovoltaic technology and geothermal pumps, both of which, the practice believes, were key to securing planning consent.