Passive House Blanden / HASA Architects

Architects: HASA – Architecten
Location: Belgium
Lead Architect: Sarah Flebus
Area: 425.0 m2
Project Year: 2011
Photographs: Liesbet Goetschalckx

Engineering: Engelen ingenieurs bvba
Energy Advisor: SVEnergy BVBA
Landscape Architect: Wim Collet

Text description provided by the architects. Presently energy efficiency is already and will become an increasingly, important parameter in the architectural design process. More and more it overrides architecture generally and daylighting design particularly.

In this project for the design and realization of an energy efficient one family house, we explored, together with the customer, the frontiers of feasibility.

We finalized the plans through an intensive and fascinating design process in cooperation with “The design office of energy and sustainability” (“Het studiebureau energie en duurzaamheid”). We succeeded in combining the energy efficiency standards (“Bouwen volgens de passiefhuisstandaard”) and the particular requirements of the owner and our own architectural vision.

The trapezoidal form of the terrain defined the volumetric form of this detached house (trapezoidal floor plan). The natural slope led to a “split-level”. This creates a fascinating spatial and visual relation between the different living spaces. All rooms were positioned taking account of an optimal orientation, the contact with the garden and the desired relations with the neighbours.

A well thought-out, energy efficient outside wall with perforations where needed encloses the house and manages the relations between the interior and the exterior. The central open stair well unlocks the different spaces. Interior windows provide additional visual relations.

An on-site terrace provides outdoor space to the nurseries and the second office. A continuous bar completes the form of the back and protects the interior space from the sun and the rain. The cantilever on the southern façade provides the necessary shadows and the, in the design integrated, covered outdoor space.

There is plenty of daylight in the house. Many windows have an orientation to the south or to the west, allowing the optimal use of passive sunlight heat gains in the heating season. In the summer the sunlight heat can be controlled and blocked by fixed and mobile sun protection systems. An efficient heat pump takes care of heating and the production of warm water. Photovoltaic cells deliver the electricity for the motor of the heat pump and the other household electricity needs. The hygienic ventilation system is equipped with a very efficient heat exchanger.

The house is an hybrid between a solid construction and a timber frame house. The massive nucleus provides the house with a highly improved thermal inertia. This is enhanced by lots of exposed concrete: an easily activated mass. This preserves the coolness longer inside in the summer and delivers the stored heat in the winter. Prefab isolated sandwich panels with mineral wool between wooden I-profiles warrant a continuous isolation shell. A lot of attention was given to the airtigthness of the building shell.