New phase in the building process - 19/10/2011


The construction of the new building will soon enter a new phase: the installation of solar panels on the roof. We would like to tell you about two particular aspects of this roof: ‘cost optimisation’ and ‘surprisingly sustainable’.

Cost optimisation
The original idea encompassed a wooden roof, insulation material, roof covering and an aluminium frame and the roof panels themselves. While we were drawing up the plan, we saw that the costs for the solar panel roof exceeded the budget. We investigated whether another solution was possible, because it turned out that the total construction was going to involve a lot of money. First of all we analysed the functions and then it appeared that a number of things were double in the construction. Couldn’t the solar panels function as roof covering themselves? Couldn’t we do without the aluminium?

In the end, we arrived at an adjusted construction, using elements of greenhouse constructions. Solar panels are incorporated directly into the roof construction there, instead of in the glass. Underneath this we designed a light-weight insulating packaging, so that the total functionality remained the same while the costs were reduced substantially.

Surprisingly sustainable
In the choices that we needed to make, we used our common sense as much as we could; therefore we thought that solar panels were one of the better alternative sources of energy. In GPR* rating, however, these panels score lower than we thought, because GPR considers the material content as a more important criterion than the generation of energy. (*GPR is an official instrument to stimulate, assist and assess the sustainable construction of buildings.) We could of course choose to try and improve the score. But it did not square with our principles to just put the solar panels on the adjoining shed instead, only to get a better score.

We decided to keep having faith in our own vision and common sense and to accept the relativity of standards.

Bert van Helvoirt (

Van Helvoirt Groenprojecten
 (landscaping projects) is currently realising one of the most sustainable office buildings in the Netherlands. For the realisation of this office, Building Team + was put together. Building Team + is a concept of Wim van Dijk of Klostermann Nederland BV and is realised in practice in cooperation with Bert van Helvoirt of SHFT. Therefore we will also write about this unique project on this website. The realisation process can also be followed on (in Dutch).