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Finished work
1240,16 m²
1088,35 m²
10,32 KWh/m² year
1,68 Kg CO2/m² year
4,75 KWh/m² year
Blower door n50:

Ca L’Antoniet

These are high energy-efficient passive houses: a four single-family semidetached dwellings development in Sitges.


Conditioning Factors

This project emerges from a private self-developer initiative interested in building low energy-use dwellings, which is a conditioning factor to be taken into account in every project’s decision, whether constructive or design-related. Therefore, the project follows Passivhaus constructive principles.

Thermal Insulation

The façade is planned with an external continuous envelope based on an external thermal insulation (ETICS) made with 15cm of expanded polystyrene. The insulation for the basement is made from the inside of the retaining wall with 5cm rockwool batter. The clearance between the ground on the (habitable) ground floor and the (non-habitable) parking space on the basement is insulated by means of 10cm extruded polystyrene (XPS) planks installed on the ground. Due to the roof decks’ high sun exposure, these are insulated by means of 20cm extruded polystyrene (XPS) planks.

Thermal Bridges Control

One of the most important decisions is having an external continuous insulation preventing the typical thermal bridges of a conventional building with an internal insulation. By counting on an external insulating continuous envelope, we can protect every forging edge and control the points where they meet with the joinery. Besides, all the necessary constructive solutions are adopted in order to reinforce those points prone to thermal bridges such as blind blocks. This problem is solved using prefabricated expanded polystyrene blind blocks in order to secure continuity on the façade’s external insulation.


These dwellings provide greater airtightness than a conventional dwelling. To comply with this Passivhaus standard requirement, an airtight line using specific sealing based on tapes and paints such as Blowerproof and Soudatight LQ paints is defined for every potential point of air infiltration, whether they are façade-forging or façade-joinery meeting points. Expansion seams are also used there to further reinforce this concept and avoid any unwanted air infiltration. Finally, the dwelling has undergone a Blowerdoor overpressure test in order to measure and control the envelope’s airtightness.

High-performance Joinery

High-performance double-glazing joinery with air chamber and thermal bridge break along with solar control (3+3/16/4+4) is chosen. The joinery+glass ensemble provides a a Uw 1,60W/m2K transmittance, much lower than a conventional joinery’s, meaning a higher resistance to the heat loss.

Sun Protection

For the house to be protected from the sun in summer, solar protections on the most exposed windows, located on the southern façade, have been installed. On the ground floor, provided with protection of balcony slab, a motor-driven canopy made of acrylic fabric is installed. On the balcony of the first floor two horizontal sliding metallic planks have been installed. In addition, all Windows are provided with motor-driven aluminium thermal blinds.

Ventilation Adjustment

To ensure comfortable ventilation, a mechanical ventilation system through a Zehnder dual flow enthalpy heat recovery unit is planned for providing high interior comfort. Its main function is exchanging psychometric properties (temperature and humidity) between the supply air and the expelled air of the dwelling while ensuring the adjustment of such ventilation and achieving a greater air quality through different specific filters. The air introduced inside the dwelling is warmed before expelling it by recovering up to 90% of the indoor air heat which would be otherwise expelled without being utilised. Therefore, by preheating the supply air we manage to reduce the conditioning energy demand.

Canadian Well

This is a technique used for utilising the underground steady temperature and one of the simplest systems employed in passive or bioclimatic houses architecture. By means of the air circulation through the underground superficial layer, coolness in summer and warmth in winter are provided to the dwellings. This means a passive system at no energy cost. Every dwelling has its own Canadian well connected to the heat recovery unit in order to further improve performance, as the supply air is preheated during its journey through the buried conduits of the well, thus making use of the deep ground steady temperature before reaching the recovery unit and be supplied indoors.

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