Mirador de Gracia: Catalonia’s 1st all-electric Passivhaus certified care home opens its doors
Mirador de Gracia, located in Barcelona, Spain, is the first Passivhaus certified care home in Catalonia,making itone of the most comfortable and energy-efficient care homes in the country.
Mirador de Gracia: Catalonia’s 1st all-electric Passivhaus certified care home opens its doors
Mirador de Gracia, located in Barcelona, Spain, is the first Passivhaus certified care home in Catalonia, making it one of the most comfortable and energy-efficient care homes in the country.
The building was designed by Joaquim Rigau, Director General of FIATC Residencias, and developed by FIATC Residencias, as part of an investment programme of over 50 million euros with a capacity of more than 600 beds, 150 day-care places and more than 200 jobs across 5 new care homes in Barcelona, Viladecans, Vilanova, Alicante and Elche. All new FIATC care homes are in the process of Passivhaus certification.
Praxis Resilient Building has carried out the Passivhaus design and consultancy, PHPP calculations, thermodynamic and daylighting simulation, design of the thermal and airtight envelope, 2D and 3D thermal bridge calculations, HVAC systems consultancy, preliminary Blower Door tests and Passivhaus site supervision. Energiehaus Arquitectos were certifiers for the project.
Located in the Collserola hills with stunning views down to the sea and the port of Barcelona, Mirador de Gracia has a gross floor area of 6,692 m², distributed over eight floors with three co-living units adapted to the needs of the residents. 75 bedrooms provide a maximum capacity of 143 residents, with facilities such as a gym, pharmacy, industrial kitchen (with daily production of around 469 meals), laundry, hairdresser, seven sitting rooms and two roof gardens.
With a 59 kWp rooftop solar PV installation, this 100% electric building generates around 26% of its annual energy consumption, contributing to significant operational savings and reduction in CO² emissions. Heating, cooling and hot water production are provided by high-efficiency air-to-water heat pumps, eliminating the use of gas or other fossil fuel energy sources.
Given that care homes are power hungry buildings with strict thermal comfort requirements, the efficiency of the building will translate into a projected 70% reduction in energy costs compared to conventional care homes.
The FIATC Residencias technical team, with more than ten years of experience in the sector, has delivered the interior design, with all the furniture designed specifically to guarantee maximum comfort for both residents and staff working at the centre.
The fact that Mirador de Gracia is Passivhaus certified helps to maintain a stable indoor temperatures throughout the year, acoustic comfort to ensure rest, and good indoor air quality that helps reduce respiratory problems and improves quality of life and health for residents, while providing environmental and economic benefits through reduced energy consumption. Ultimately, the combination of efficient technologies and an optimized thermal envelope makes Mirador de Gracia a benchmark for sustainable architecture, demonstrating that well-being and sustainability go hand in hand.
Architectural design
Located in a privileged setting in the Collserola hills above Barcelona, Mirador de Gràcia has been designed to blend harmoniously into the landscape with a structure made up of two blocks of differing heights, allowing the creation of a large roof garden that connects the day areas and dining spaces, encouraging social interaction and enjoyment of the natural surroundings.
The architectural design is based on more than a decade of experience in managing nursing homes, with areas and furniture adapted to the needs of residents and staff. Priority has been given to creating warm and accessible interior environments, with 7 single rooms and 68 double rooms, all of which have natural light and exterior views.
Thermal envelope
The thermal envelope consists of 12cm of Sto EPS insulation on external walls, eliminating thermal bridges from the reinforced concrete structure. Additionally, there is 5cm of Knauf Insulation glass wool installed internally in the service void, manufactured with more than 80% recycled glass, with the E- Technology binder, which is plant-based and free of added phenols and formaldehydes, protecting both workers during construction and future occupants from harmful emissions.
The windows consist of Cortizo aluminium frames and low-emissivity and solar control glazing with argon gas, installed in wooden pre-frames and sealed with Ampack airtight tapes to eliminate air infiltration. Insulated EPS Cajaislant shutter boxes reduce heat loss from the external venetian blinds that provide automated shading for all windows and reduce cooling demands.
During the design phase, all construction details were studied and optimised to minimise or eliminate thermal bridges and eliminate cold spots.
10 preliminary Blower Door air tightness tests were done on the building, prior to the final test, with a result of n50 = 0.6 ren /h, making it one of the largest and most airtight buildings in Spain.
During the design phase, a series of thermodynamic and daylighting simulations were carried out using the DesignBuilder-EnergyPlus modelling tool, to optimise thermal performance and natural lighting. One of the objectives was to study the solar incidence on each façade and determine where low-e or solar control glazing would provide lowest heating and cooling demands and maximum daylighting. By reducing the glazing solar factor, the light transmission (natural light) and summer solar gains are reduced, with a consequent reduction in energy consumption from air conditioning; but free solar gains are also reduced in winter, with a consequent increase in heating energy consumption. The results of the study helped specify the glazing on each façade, finding a balance between daylighting and heating and cooling consumption.
Heating, cooling and hot water systems
Space heating and cooling is provided by 2 Hitachi Samurai air-to-water heat pumps (providing both heating and cooling) and 1 Hitachi Samurai chiller, with a total installed heating power of 488 kW and 507 kW of cooling power.
The heat pumps power indoor ducted fan coil units in the bedrooms and common areas, together with heating and cooling coils in the AHUs (air handling units), that warm or cool ventilation supply air, covering a part of the heating and cooling loads.
For DHW production, there are 5 Hitachi Yutaki air-to-water heat pumps, with two 1,000 litre hot water thermal storage tanks. DHW recirculation is controlled by the return temperature, to minimise heat losses in winter and internal heat gains in summer.
Ventilation and air renewal systems
The building has a highly energy-efficient balanced mechanical ventilation system with heat recovery, with 3 Passivhaus certified Swegon Gold RX air handling units that provide a maximum combined flow rate of 27,000 m3/h. The units have a sensitive heat recovery rate of 84%, with a maximum fan power consumption of 0.45 Wh/m3. Using the building’s control system, flow rates are adjusted according to occupancy. In the common areas, there are CO2 sensors that control motorized dampers, which open and close according to the concentration of CO2 and occupancy. Flow rates in bedrooms are regulated by time schedule, with CO2 sensors in a selection of rooms to monitor air quality.
The mechanical and electrical systems in the building were installed by Agefred.
All-electric industrial kitchen
The integration of an industrial kitchen in a Passivhaus care home is complex: equipment for food preparation, cooking and dishwashing consumes large amounts of energy and water, produces high internal heat gains (both latent and sensible), and requires high ventilation flow rates to remove contaminants.
Praxis undertook an extensive study in the design phase, to look at ways of eliminating gas-powered cooking equipment (generally the default in commercial kitchens and incompatible with the airtightness requirements of the Passivhaus standard) with efficient electrical equipment and dishwashers with low water consumption.
Peak kitchen hood extract air flow rates can sometimes reach ≈ 50% of the total ventilation flow rate that is required for the whole building. To this end, we specified an induction kitchen hood with a control system that modulates the air flow rate in the cooking area using temperature and smoke opacity sensors. In this way, the flow rate is adapted to cooking intensity, heat losses are greatly reduced, and fan electricity consumption can be reduced by up the 80%. The sensors are integrated into the induction hood and are easy to access and clean.
Renewable energy system
The building has a 59 kWp photovoltaic generator installed on the roof, with 131 Longi 450 Wp polycrystalline panels, and three SMA Sunny Tripower inverters, with an efficiency of 98%.
Monitoring
The Building Management System (BMS) is used to monitor the building’s energy consumption and indoor air quality, providing a means of assessing the building’s performance and comparing it with PHPP predicted energy consumption.
Conclusion
Mirador de Gracia sets a new benchmark for sustainable, energy-efficient care homes in Spain. By combining cutting-edge Passive House design, all-electric operation, and renewable energy generation, it demonstrates how comfort, health, and sustainability can coexist. This pioneering project not only reduces energy costs and carbon emissions but also enhances the well-being of its residents, proving that the future of care homes can- and should- be both resilient and environmentally responsible.
Photographs: Praxis, Salva Lopez & Miriam Castells