13. January 2015

"POWER HOUSE nZEC! Study Visit to two exemplary multi-family buildings in the Brussels Capital Region" - 13 January 2015, Brussels, Belgium

USH - l'Union Sociale pour l'Habitat (the French Federation of Social Housing Providers) organised in collaboration with Bruxelles Environment (an initiative of the Brussels Capital Region) a study visit to two exemplary multi-family buildings located in the Brussels Capital Region.

During the day, participants had the opportunity to visit the following two sites and hear directly from the architects the technical aspects related to the projects:

• Rue Pierre Strauwen, 1020 Bruxelles
  The project concerns the renovation of an empty building, built in the 30s, consisting in 16 social apartments. Initially, the idea was to create 12 residential units meeting the energy performance of buildings regulation; however, it soon transpired that “very low-energy” units could be created at reasonable additional cost. Indeed, this renovation will be the starting point to renovate the complete island; not just the apartments, but also the common areas, so as to foster social exchanges and biodiversity.
  
  Once the first building has been renovated, the Contracting Authority intends to develop a collective system to heat all the buildings. This centralization will generate enough of a heating capacity to choose alternative energy-production systems, such as co-generation. A feasibility study has confirmed the potential interest of this system, subject to legislation allowing tenants to sell excess electricity to the supply board, and even though the need to sell excess electricity back to the grid is a common requirement, especially in the case of photovoltaic collective appliances, a suitable legal framework does not yet exist. Therefore, the excess electricity could at least supply the local communities, and entitle the project to green certificates.
  
  The same idea has come forward with the installation of a centralized earth heat exchanger providing all the buildings; the purpose of this network is to first, preheat ventilation new air in winter, so as to reduce the risk of frost forming in the ventilation unit, and second, cool down new air in summer, so as to minimize the risk of overheating. According to the engineers, the complete network will recover about 5000 kWh per year for a heat dissipation of 2900 kWh per year.
  
  
  
• Rue de Bonne, 1080 Molenbeek-St-Jean
  The project has two distinct facilities, both achieving the passive level: a volume comprising 13 houses and a school (kindergarten and elementary). The implemented cooling system facilitates high thermal inertia, reduces internal loads of the school, reacts with the solar gains through fixed shading devices for the school and sliding and fixed perforated blinds for the housing units and uses the building shade between them.
  
  A centralised management system acts locally and in a manner that is adapted to the specific needs of each room. The user can operate the system and manually regulate the heating, ventilation, solar shadings and artificial lighting. Concerning water management, the use of water is reduced by overcoming wastage: pressure limiter, time-delay taps with limited flow, infrared taps for the kindergarten, etc. The rainwater is collected in two 20m³ concrete tanks and it is used for sanitary facilities, maintenance, domestic washing machines and watering.
  
  A user guide is provided to the school and tenants. In addition, the user is provided with data sheets indicating the choices made and the reasons behind making them. This guide provides a series of instructions and keys to understanding that not only helps the user save energy but also prolong the life of the building and its installations, which represents an even greater amount of energy saved in the long term.

For further information on sustainable buildings in the Brussels region, please do not hesitate to visit: http://www.sustainablecity.be/themas/sustainable-building.