The community of property owners, under the technical advice of Vitoria-Gasteiz City Urbanism area, and with the collaboration of VISESA decided to approach an integral renovation project with three main design strands: building envelope, accessibility, building facilities.

Regarding accessibility, the key issue was to confront the lack of space inside the building to place a lift. The only solution was to demolish the existing stairs in order to replace them with a single section stairs and to install a new external lift. This external lift was possible by the cession of public land by the municipality. This land was also used to provide a new access from the back street of the building, thus avoiding the steps that exist in the access from the main road.

In relation to the building envelope, the transmittance values for the façade , roof and ground slab were highly reduced with the placement of a thick insulation layer around the whole envelope. The insulation was placed paying special attention to the construction detail, forming a continuous thermal insulation skin and therefore minimizing thermal bridges. The façade solution consisted on a combination of rock wool external insulation system(120 mm) and a ceramic ventilated facade with mineral wool as insulation (120 mm). The original interior carpentry in all the dwellings was conserved, and a second exterior carpentry was placed in line with the new outer thermal insulation. Air tightness was reinforced to avoid at maximum the uncontrolled infiltration, as the dwellings have been equipped with a dual flow ventilation with heat recovery (HRV).

In relation to the energy systems, during the first workshops of the design phase it was decided to centralized the thermal generation and remove the inefficient individual systems (old gas boilers, LPG and electric heaters). However, the lack of common space and the limited number of dwellings (30), made the installation of a central heating economically unviable, and it was finally decided to maintain the individual generation systems, but replacing them with new highly efficient condensing gas boilers.

Along with this renewal the most important change will be the introduction of new communal facilities:, photovoltaic panels (3.6 kWp installation) to reduce electricity consumption in common areas and a ventilation system with heat recovery (HRV), which will help to maintain high indoor air quality while further reducing energy demand.