Architects just want to develop attractive buildings

Roof of ECN building, with photovoltaic cells as sunshade.

Solar panels used sparsely in houses and buildings

A building needs a roof, and an external wall. These are two of the compulsory architectural building blocks. Solar panels are not compulsory. But this does not mean architects are not interested in them. “There is still a great lack of understanding about the possibilities and impossibilities of using PV in buildings,” Henk Kaan of ECN explains. In an international partnership, he and fellow architects drew up a number of guidelines, so that architects and project developers can get past the idea that solar panels are merely ‘wonderful’ or ‘incredibly ugly’.

“Only a small proportion of the solar panels used in building are successful from an architectural point of view.” In saying this, Henk Kaan, who works for ECN Efficiency & Infrastructure and is a qualified architect, does not mean that architects are fools. On the contrary. “For most architects, the visual and aesthetic aspects are the most important. They try to create a spatial object with lines, shapes, colours and texture. These are the challenges for the architect within the customer’s programme of requirements. But they do not immediately think of using a solar panel as an interesting building material. There is still much to be achieved here.”
Kaan still clearly remembers the first large-scale PV project in Dutch housing construction. This was in the Nieuw-Sloten district, south-west of Amsterdam. The architect was Machiel van der Torre, who had never had any involvement with solar panels before. “This was the customer’s requirement, and Van der Torre was receptive to it,” Kaan explains. “He regarded it as an architectural challenge. But not all architects think this way.”

Rem Koolhaas, Renzo Piano
When asked what could lead to a breakthrough, Henk Kaan thought carefully. “A tried and tested formula is for a very well-known architect to include solar panels in a much-discussed design. If Rem Koolhaas, Renzo Piano or Norman Foster were to design a building in which solar panels were superbly integrated, you would see that other architects would follow suit. The leader would have set the direction. Customers would also show more interest. This mechanism has worked throughout the history of architecture, and it would work here too.”
On the other hand, Kaan also knows architects who have gone overboard with ‘sustainability’, and swamp their designs with it. They are suffering from what someone once called the ‘windscreen wiper effect’, he insisted, in which the windscreen of a car is made in the ideal shape to be cleaned with the wipers. The rest of the car then has to be made to fit this windscreen. Translated into the context of architecture, these architects consider sustainability so important that it dominates their design. “Architecturally, the design is then unbalanced, while a good architect is a designer who makes balanced compromises.”
Take note: sustainability is not a curse to the architectural world. Of all the energy technologies, the solar panel is the most suitable for integration into the built environment. It saves introducing a separate load-bearing construction and it saves space. Architects have to learn to handle PV elements, Kaan claims, but it is useless to make this compulsory. “This did happen in Germany. The government buildings constructed in Berlin after the reunion of Germany had to provide 10 percent of their electricity by means of solar panels. This included the historic Reichstag building. The bizarre result was that from the glass dome at the top of the building, you look down onto a lower roof supporting a jumble of solar panels. You can’t see them from the street, because the architect hid them away behind a parapet.”

Solar panels are an option
A team of 10 architects, from several countries, looked at architectural criteria for the use of solar panels in buildings as part of a work programme run by the International Energy Agency. They put forward the following list:
• Natural integration of solar panels
• Panels must fit in architecturally with the total building concept
• Good total composition of colours and materials
• Panels must be in harmony with the lines and pattern of the design
• They must fit in with the character of the building
• The PV system must be finely integrated with the other construction technology
• The PV system must stimulate innovative designs

These criteria seem so logical, so universally applicable for any building material. “That’s true,” agrees Kaan. “The fact that they are linked so explicitly here to solar energy is related to the fact that solar panels are not indispensable. Windows, a roof, doors … these have to be included, whatever you design. Solar panels are an option that you can choose in order to achieve the desired energy performance. This means there is a risk that the solar panels will be an addition to the original design, often at a late stage, so that the architectural integration is easily lost. Take a look in Germany, where the solar panels have just been dumped on the roofs of many detached houses. Everyone agrees that this looks awful.”

Solar panels have a high-tech image
Architects want to fill the space between sky and earth with something beautiful. To do this, they use materials that they consider suitable. “Solar panels are not materials that an architect thinks of straight away when looking for building materials,” Kaan explains. “Firstly, they were designed by physicists, who were thinking in terms of efficiency. Aesthetic requirements did not play a role at that stage. So the architects are not immediately enthusiastic.”
Now we see a manufacturer presenting his latest innovation: a roof tile incorporating a PV element. “He expects architects to be excited by his integration of a new technology in a building material that has been around for centuries, and that the whole of the Netherlands will soon be full of these. Perhaps it is useful for the retro-architecture of social housing areas, but I don’t think there are many architects who want to take a material that has a ‘high-tech’ image and then retro-fit it into old-fashioned elements. If you have a new ‘building material’ like solar panels, then you should also use them innovatively in a way that does justice to their high-tech image.”

Cheaper than stone
Architects have their own reasons and methods for designing buildings the way they do. However, they will always be constrained by the customer’s requirements. “Project developers use buildings as a way of earning money from their investment. The object must be reasonably neutral, both aesthetically and where price is concerned. This might lead you to think that solar panels are right out of the picture, but this is not the case. Solar panels can have a dual function, for example as a generator of electricity and as protection against the sun or covering for a facade. Per square metre of facade facing, a solar panel is cheaper than stone. So even office buildings can supply solar power.”

Contact
Henk Kaan
ECN Efficiency and Infrastructure
Tel.: +31 (0)22 456 4689
E-mail: Henk Kaan 

This ECN-Newsletter is free for publication, under the strict condition that the source is mentioned: www.ecn.nl/en/news