The tensions of the post-war reconstruction process are released in this place. Beside the rail yard stands a group of residential and manufacture-related buildings, characterised by unauthorised development, odd parcelling, invasive infrastructure and heavy traffic. The client intends to extend a dwelling in order to take advantage of the regional law that allows a volume increase and of the tax incentives for building renovations. The chosen strategy doesn’t oppose the anti-design criterion that guided the development of this part of the city, it goes along with it instead. The addition is juxtaposed to the existing building, its materials and construction techniques reveal its autonomy. A double perimeter articulates the two-level plan with a solarium on the roof. The outer expanded metal perimeter traces the footprint of a demolished volume. Its full-height extrusion defines the building’s elevations and an ambiguous space – neither inside nor outside – conceived as an expansion of the domestic rooms, which nevertheless doesn’t count as built volume. The inner perimeter follows an oblique line generated by the minimum lawful distance from the opposite house’s façade. This condition distorts the spaces and establishes their use. Responsive is architecture adapting to the urban apparatus.