If the energy of solar radiation can penetrate a system almost unhindered, but the outflow of heat is restricted, this is called the glasshouse or greenhouse effect. While this effect is increasingly becoming a problem for the earth, a family house in Rekkem, Belgium is using the effect in a positive way.
The architect Koen Vandewalle has designed a house that is housed in a greenhouse. The house-wthin-a-house also claims to be autonomous from the local energy grid and consists exclusively of recyclable, reusable or local bio-ecological materials. The building follows the idea of circular construction, in which the focus is on the reuse of materials and the maximum use of natural energy sources.
The house for a family of seven with a living space of 170 m2 was designed as a timber structure within a 12.2 m wide by 30 m long greenhouse with a ridge height of 9 m.

The hot dip galvanized steel structure of the greenhouse consists of a series of ten frame elements consisting of 6 m long columns and beams
The galvanized steel greenhouse, protects the house and garden from wind and weather, creating a balanced microclimate. The robust and resistant bolted construction can be completely dismantled if required.
The house itself consists of a timber frame insulated with cellulose and wood wool, which rests on a base made of recycled concrete.

The energy for the house comes exclusively from the sun. The solar elements provide the necessary energy for the production of hot water and electricity required for the house
The hot dip galvanized steel structure of the greenhouse consists of a series of ten, 6 m long columns and beams.
“Steel was the only material that could be used for the greenhouse function,” says Koen Vandewalle, adding: “Steel is 100% adaptable, can be dismantled and recycled. Good corrosion resistance and a long service life are guaranteed by hot dip galvanizing.“
To ensure that the house is independent of public utilities, rainwater is cleaned using a lava filter and fed into three rainwater wells of 20,000 litres each. Waste water goes to a septic tank, where effluent is pumped onto reed beds.
The energy for the house comes exclusively from the sun. Solar panels are built into the roof structure of the external frame and provide the necessary energy for the production of hot water and for electricity required for the house.
So that it does not get too hot in the summer months, the glass roof and some door elements can be opened for cooling with the energy surplus of the solar elements operating the air conditioning system.
The patch work of solar panels also serve as a shading system for the house.
Although the initial cost for the house was higher than for a more traditional design, the architect‘s objective was to use it as a possible test case for higher density housing.