Masies de Mollet & Mirador de Gracia achieve n50=0.6 ACH in their Final Blower Door Tests!
Two recently completed care homes in Barcelona, now in the final stages of Passivhaus Certification, have reached an outstanding n50=0.6 ACH in their final Blower Door tests.
Masies de Mollet & Mirador de Gracia achieve n50=0.6 ACH in their Final Blower Door Tests!
Two recently completed care homes in Barcelona, now in the final stages of Passivhaus Certification, have reached an outstanding n50=0.6 ACH in their final Blower Door tests.
This remarkable achievement makes them the largest and most airtight buildings ever constructed in Catalonia!
Residencia Mirador de Gracia
Developed by FIATC Residencies and designed by Joaquim Rigau of GENARS, with Passivhaus design from Praxis
The two care homes Masies de Mollet and Mirador de Gracia are on the home straight for achieving Passivhaus Classic certification.
Thanks to a high-performance thermal envelope and highly efficient ventilation, heating, cooling and hot water systems, they will offer exceptional indoor air quality, superior thermal comfort, and projected savings of 70% in operational running costs compared to the owner’s other care homes.
Blower Door test
A Blower Door test is used to assess a building’s air
permeability, helping to locate and seal air leaks and drafts.
Achieving a high level of airtightness is essential for Passivhaus buildings. The principle of “build tight, ventilate right!” helps reduce heat loss by up to 30%, while improving thermal and acoustic comfort, and maximizing the efficiency of mechanical ventilation, heating, and cooling systems.
Mirador de Gracia
| Floor area [m²] | 4595 |
| Internal Volume [m³] | 13863 |
| Building height [m] | 29 |
| Infiltration rate @50 Pa q50 [m³/h]: | 8912 |
| Infiltration air charge rate @50 Pa n50 | 0.6 |
Masies de Mollet
| Floor area [m²] | 4566 |
| Internal Volume [m³] | 15624 |
| Building height [m] | 15 |
| Infiltration rate @50 Pa q50 [m³/h]: | 9758 |
| Infiltration air charge rate @50 Pa n50 | 0.6 |
In both the Mirador de Gracia and Mollet projects, Praxis played a key role in preparing the construction teams.
They delivered online Site Supervisor training to the design and construction teams before breaking ground. The courses covered the essential requirements for Passivhaus certification, including airtightness strategies, insulation specifications, thermal bridge-free detailing, and HVAC and DHW commissioning.
On-site, Praxis conducted Passivhaus supervision and carried out preliminary Blower Door tests. Given the complexity of the buildings, the Mirador project required 10 preliminary tests—both partial and full—to identify leaks and seal them. The Mollet project underwent 6 preliminary tests before successfully passing the final assessment. Airtightness was achieved using gypsum plaster on exterior walls, reinforced concrete slabs for the ground floors and roofs, and windows sealed with tapes to the airtight layer, using Ampacoll Fenax tapes supplied by Ecospai. Service penetrations were sealed using flexible foam and airtight paint. A 1:1 full-scale mock-up was also built and tested, providing the construction teams valuable hands-on experience.
After overcoming numerous challenges and a fair number of sleepless nights, the Praxis team, led by Oliver Style, celebrates this significant milestone in Passivhaus construction in Spain. Work continues on four more Passivhaus care homes for the same developer, all aiming for certification. Stay tuned!
