Lens°Ass Architects’ House V is a renovation project on a house in Overpelt, Belgium. The owners asked Lens°Ass to renovate the living area only. House V, an anonymous building in a residential neighbourhood, had low ceilings and was quite dark; it turned out to be impossible to renovate the living room without redoing the entire house. The architects created an underground level rather than making the house taller, maintaining the same height as the neighbouring homes (only 2,20 metres in the living room). This responded to the owners’ request for a large underground level, to be used not as a storage area or garage, nor strictly as a bedroom area, but as a true living space containing a bedroom, a study, a wardrobe and a bathroom in a complex, extensive layout in which they would spend time during the day as well as at night.
The need for shelter and security made the underground level rather like a “bunker”, which Bart Lens manages to open up by digging into the soil, as in the steps leading from the bedroom up to the garden or the round windows in the living room. Brief incursions of light or fragments of sky transform a closed space into an environment for living.
But the layout of the underground floor is directly derived from that of the ground floor. Two ovals side by side become cylinders supporting a massive concrete roof, with brick walls forming an outdoor living area without penetrating one another or enclosing the space, joined by glass secondary walls defining the indoor living space. The first cylinder contains the kitchen, the second the living room. Behind the round fireplace in the centre of the room is the staircase down to the underground level, leading to the study, where there is another fireplace, and other, more private spaces defined by oblique walls, a conceptual continuation of the walls on the ground floor.
The choice of materials is particularly important in this project. The materials are left in their natural state, such as handmade bricks with flush mortar joints finished by hand with a brush, bare concrete, and an outdoor pavement of stone which continues part way into the interior, where it meets the wooden flooring of the living room: 6 metre long strips of Douglas fir cut to size especially for the room. The brick walls are topped by a V-shaped concrete roof set at a slight angle to allow water to flow off, with an overhang to shelter the home from the sun in summer. Protection of the environment is behind all the choices made in this construction: the building’s high thermal mass keeps it warm in winter, while natural ventilation through the windows and the decision to build underground reduce the need for air conditioning and a heat pump warms the home in winter.
Lastly, rainwater is stored in a big tank on the roof of the round volume garage and purified by plants, creating beautiful circular reflections on the wall facing it at certain times of day.
Architect: Lens°Ass Architects
Location: Overpelt (Belgium)
Roof in concrete
Structure made of concrete and hand-made bricks
Living room floor made of Douglas fir
Slate outdoor pavement
Photos by © Bieke Claessens