Description

Can Mati, Viladecans

Passivhaus EnerPHit Classic Retrofit of a Historic Farmhouse

Located in Viladecans (Barcelona), Can Mati is a historic rural building that has been sensitively renovated to become the first Passivhaus-certified home in the city. The deep energy retrofit retained the existing structure and architectural character while creating generous, light-filled interior spaces. The project has achieved Passivhaus EnerPHit Classic certification.

The energy retrofit focused on improving the thermal envelope and installing efficient MEP systems, as well as an on-site photovoltaic array for self-consumption. A remarkable airtightness value of n50 = 0.5 ach was achieved—meeting the Passivhaus criteria for new builds—by using simple solutions such as plaster finishes and existing roof membranes, with airtight membranes applied only in specific locations.

Wherever feasible, insulation was applied externally. Due to conservation constraints, the upper part of the main façade was insulated internally using cork aggregate and lime-based Diathonite mortar (by Diasen), while the courtyard façade was externally insulated with a rock wool ETICS system and lime-based Com Cal render. Horizontal elements were insulated with wood fibre, and an additional XPS layer was added above the roof membrane to prevent interstitial condensation. The result is a respectful, high-performance retrofit that has reduced heating demand by 90% compared to the original condition—setting a benchmark for energy-efficient retrofitting of historic buildings.

Links:

International Passivhaus Projects Database
Spanish Passivhaus Projects Database