First Passivhaus social housing building for EMVS. Manubuild, Carabanchel 34 by Ruiz Larrea & Asociados

Project description by Ruiz-Larrea & Associates Architects

Madrid's Council Housing Department has developed the construction of this dwelling block located in the popular neighborhood of Carabanchel. The building is designed by Ruiz-Larrea & Associates Architects and has obtained the Passivhaus Classic certification in sustainable building construction.

The aim of Ruiz-Larrea & Associates has been an energy-efficient design, indoor air quality, and high comfort standards of every housing unit. The project is developed with constructive systems conceived to achieve PassiveHaus standards (ETICS -External Thermal Insulation Composite Systems-, air-insulated façade, high-performance window framing…) and also minimizes heating and cooling demand by the carefully avoiding the many thermal bridges of an existing structure.

The adaptation of the structure to the standard's requirements has led to a nearly zero-energy consuming building (NZEB) with a 60% reduction in energy demand and consumption. The main criteria to achieve the NZEB certificate are based on the so-called Passivhaus construction standards.

Passivhaus is the most demanding certificate regarding comfort and energy efficiency. A Passivhaus building is defined as that in which the air gets heated or cooled to achieve optimum ventilation of the indoor spaces.

The competition requirements asked for 25 dwellings of 1, 2, and 3 bedrooms and communal areas. Council's main target with this development was to cover a lack of public housing rental.

Due to the architectural organization and layout, the airtightness tests are gained with only one thermal envelope and 5 tightness lines so one single test was carried out per storey. Thus, the reduction in the number of tests to be carried out has had a positive impact on construction costs.  

Besides, bioclimatic design criteria have been met as well as energy efficiency systems, eco-construction standards, and indoor comfort solutions (air quality, allergen-free, and VOC -free indoor spaces). These also applied to water management and consumption.

- House typologies

The housing block is organized around the vertical staircase and lifts shaft, which links to a distribution corridor facing north. This layout allows all units to enjoy double orientation (north-south) on their façades, therefore improving natural ventilation.

The unit layout provides a clear separation of spaces. That means, there is a day-living area where the kitchen, utility room, eating area, and living rooms are located and a different area (night-living) where bathroom and bedrooms are located staying as quiet as possible from the day-living area activities.

Facing south the window frames are vertically shaped while they turn horizontal at the north façade. The parking facility was already designed in a preliminary phase and it is located in the second basement provided with a semi-automated parking system.

- Building Specifications:

•    High indoor thermal comfort, both in winter and summer. Comfort range values between 20-25C
•    High indoor air quality provided 24/7
•    Thoughtful display of construction processes to minimize any thermal bridges, water leaks, or condensation, therefore reducing the risk of construction aging problems.  
•    Affordable construction prices  
•    Lower energy bills  
•    Long-term construction solutions. Good working order  with minimum maintenance
•    Doesn't require high skills for a proper usage
•    High levels of accomplishment both for user and owner

- Building services

Compared with a building just meeting standard codes, Passivhaus reduces the energy  demand by 60%.
Heating demand per year and area ratio: 9 kW/ (m²year)
Cooling demand per year and area ratio: 7 kW/ (m²year)
 
Cooling and Heating

High-efficiency air-conditioning system based on a Condenser Unit installed on the rooftop and an indoor unit located in the living room (3,5kW Cooling power and 3,7kW Heating)

Ventilation

For comfort ventilation with high-efficiency heat recovery, 21 Zehnder Comfoair 180 units and 4 Zehnder Comfoair 200 units have been used. The installation has been carried out vertically, integrating into kitchen furniture, with a flow range between 90-145 m3/h with F7 filters on intake and G8 on equipment return. In this way, fresh air is obtained that favors well-being, maximizes comfort, energy-saving, and the absence of mold and bacteria. The equipment with the Passivhaus component certificate, obtain a heat recovery with an efficiency of 82% (>75%) and electrical consumption of 2.7 W/h.

Renewable energy

Thermal energy panels are installed to fulfill the requirements of building standards. 8 panels have been installed in two rows, with an individual capacity area of 2,51 m² and a 9kW heat dissipater per row. It is backed up by a 60kW condensing boiler, with a coil exchanger  and two 1000l tanks.