Sustainable brick façade for zero energy home22/06/2012
For the construction of a passive house in Puurs, engineer-architect Bruno Callaert decided on elaborate insulation in conjunction with energy efficient techniques and sustainable, traditional materials. The façades are constructed of brick with roofing tiles made of clay. The advantage of this type of solid-passive house is that it can buffer more heat. In addition, this dwelling can produce as much energy as is necessary to either heat or cool it. For this reason the dwelling was awarded the zero energy home certificate.
It was a conscious choice to apply this particular building technique. This way the residents use much less of the natural resources to heat or cool their home. Initially this does require a far greater investment. But grants, tax advantages and, of course, very low annual energy costs more than compensate for this after a period of time.
Brick: timeless, stylish and durable
For the façades Bruno Callaert opted for brick. "Brick is timeless and over time has proved its reliability, yet at the same time this product is very contemporary. Brick façades are back in fashion mainly thanks to the many new ranges and new processing techniques. Also the many different sizes, different types of brick and the recent availability of brick slips have made facing bricks more topical than ever.
An additional benefit is that facing stones are resistant to ageing and do not require any maintenance. This is a sustainability aspect that is often underestimated," says architect Callaert.
"Yet sustainability is not understood to mean the same to everyone. The windows for example are made from aluminium and according to some analyses this makes them less durable. But just recently, a sustainability organisation opted for aluminium for its own offices, because it could be recycled. Plasterboard is also a perfect material for recycling. This is the so-called cradle-to-cradle principle, reusing materials from cradle to cradle."
Livorno brick provides playful bluish-black colour effects on the façade
To obtain harmony in the new neighbourhood, the architect had to take into account the specific requirements as specified by the RUP (Spatial Implementation Plan) for façades and roofs. This limited the colours that could be used for the façade to white, grey, and black.
Architect Callaert explains: "The customer wanted a dark greyish-black façade. So I drew up a reference list of all the different brands and types, because that is the best way to assess the bricks. To prevent the façade from becoming too stark, the customer preferred a handform facing brick. The choice for Livorno was quickly made because of its playful bluish-black colour effects. The fanciful surface texture of the brick gives the façade extra cachet. On top of that, Vandersanden was able to link the excellent performance requirements of this brick to an attractive price. And if the contractor also likes working with the brick, the quotes become very reasonable, which in turn leads to much more attractive results."
Joint-free façade with thin-bed mortar
Both the architect and the future owner opted for a joint-free façade to further enhance the simplicity of the dwelling. It also greatly boosts the beauty of the Livorno brick with its blue shades and textures.
The façade is one solid wall, interrupted only by 2 notches. The lower surface has been detailed in such a way that the subdivisions are not visible, even though the front door and the garage gate are integrated in this wall. The large, triple-glazed window reinforces the simplicity of the wall. It required special support, but now the evening sun can penetrate through a glass floor into the living room. "The choice to work with thin-bed mortar was also motivated by the smaller risk of efflorescence and was implemented after consultation with the contractor," says Bruno Callaert. "And gluing both the horizontal and vertical joints means there is less air circulation in the air space of the cavity wall."
Comfortable zero energy home
"The future owner did not want to make any concessions to comfort," says architect Bruno Callaert. "For example, the house has a basement and a garage. The temperature throughout the house is constant, all year round. Even in summer no cooling is needed. Also, there are no draughts. The triple glazing and the airtight profiles ensure that even in midwinter you can sit comfortably by the corner window. It is much quieter in the house too, due to the additional insulation and the absence of vents," says architect Callaert.
It is essential for a comfortable passive house to have an extremely efficient ventilation system and to obtain perfect airtightness with a so-called blower door test.
Architect Bruno Callaert: "To meet the requirements of a zero energy home, we fitted thermal and photovoltaic solar panels. We did this despite the fact that the roof was not very large and the orientation not exactly optimal. We managed to meet the requirements thanks to the low energy demand. The E level decreased to E10. More recently the financial and tax incentives for passive and zero energy homes have been cut, but fortunately this technology is becoming more and more accepted and naturally there are the energy and comfort benefits."