Koh is the first EnerPhit based restaurant in Barcelona, and means in Thai “ISLAND”. With this building, a space for gastronomic use has been renovated in Barcelona following the EnerPhit criteria. This international seal is the adaptation of Passive House in the case of retrofitting existing buildings. EnerPhit provides a protocol for very low energy consumption, combined with high thermal comfort. It is calibrated to achieve an optimal energy standard based on the life cycle cost of the building. That is, initial construction costs and energy consumption savings throughout the life of the building are valued. The KOH restaurant, which opened its doors at in 2018, has been monitored by Energiehaus Arquitectos, the designer team based in Barcelona, so to check that the adapted strategies and solutions really translate into the expected values of low consumption (kWh) and thermal comfort and health (ppm CO2). The economic analysis of the offer of the contractor has shown that the extra cost to reach this standard is relatively low, of 5% in the case of this case. The annuity cost that the developer will pay (sum of mortgage and energy consumption) is from the first year on less than the same retrofitting being hypothetically done based on the Spanish building code CTE. Main action strategies are: Continuous thermal insulation throughout the enclosure (some thermal bridges had to be accepted), Passive House windows for warm climate, Passive House certified double flow ventilation system, high air tightness and an air to water heat pump for heating and cooling. EnerPhit certification couldn’t be achieved due to the Blower Door final result email@example.com/h (“A” based measurement in a small building). The reason was the gas kitchen required openings for security ventilation and also a big sash window. Nevertheless, Koh-restaurant is having a great success not only because of the head chef, but also due to the cozy and comfortable atmosphere of the space.
Heating demand: 44 kWh / m²a
Cooling demand: 57 kWh / m²a
Air tightness: 2.8 / h
Passivhaus Designer: Energiehaus Arquitectos SLP
Architects: Energiehaus Arquitectos SLP
HA Studio - Holger Augst, construction management
Álvaro Valdecantos, photographer
Construction System: Existing work wall with thermal insulation inside. Lightweight roof of existing wooden beams, with thermal insulation (mineral wool) between cabios and additional insulation sandwich metal roof
Installations system: Ventilation combined with air conditioning system with a single network of air supply ducts, recirculation and extraction. Heat recovery ventilation (ATREA, Passivhaus certified machine) with 84% efficiency. Mitsubishi air-to-air heat pump.
TFA – energy based ground floor: 127.3 m²
C / Pujades 133b, Barcelona
Enrique del Olmo González
Year of construction: