Reference for renewable resources
Rammed earth, goat's-hair rugs and recycled oak wood are just some of the natural construction materials used by the Agency for Renewable Resources (FNR - 'Fachagentur Nachwachsende Rohstoffe') in their new offices in the northern German town of Gülzow. The building - designed by matrix architektur (Rostock, Germany) - is now the subject of a detailed FNR publication.
Rammed earth, goat’s-hair rugs and recycled oak wood are just some of the natural construction materials used by the Agency for Renewable Resources (FNR - ‘Fachagentur Nachwachsende Rohstoffe’) in their new offices in the northern German town of Gülzow. The building – designed by matrix architektur (Rostock, Germany) – is now the subject of a detailed FNR publication.
The FNR has been coordinating research, development and demonstration projects since 1994, in order to inform both companies and citizens about the potential of renewable resources. The agency was set up initially by Germany’s Federal Ministry of Food, Agriculture and Consumer Protection. Currently, the FNR manages around €53 million of grant money within the ‘Renewable Resources’ programme.
Among other things, the FNR runs the ‘Fachberatung Bauen und Wohnen mit nachwachsenden Rohstoffen’ (Specialist counselling for building and living with renewable resources). The new construction in Gülzow doesn’t just serve as its office space, it is also a reference object for working with natural materials in a public authority building. Set in a timber framework, the 923 m² house (main usable area 533 m²) offers room for 31 employees.
Wood on brick
The building is located on the site of an old potato warehouse in the grounds of the Gülzow manor house. The architects’ idea was based around a two-storey wood stack on a massive brick semi-basement, which is half entrenched into the ground. The façade cladding is made from recycled oak wood, which has only been sanded smooth on the north and south sides. The east and west sides of the facade, on the other hand, have a rougher natural profile. Windows take the form of vertical slots, while their soffits have been encased with green-coloured glass.
Half of the semi-basement is taken up by offices, while the other half (which is embedded in the hillside) contains a large, windowless archive room. The two upper floors are taken up exclusively by offices (both single and double offices as well as an open-plan office space).
In addition to the oak planks that make up the facade, renewable resources were also used on the inside of the construction, as well as in many different parts of the interior: the timber frame walls are insulated with cellulose and wood fibre, while the first and second floor are divided by a board ceiling. The interior walls have received a loam rendering and are covered with casein paint. Focal point of the foyer is a rammed earth wall, which also serves a thermal heat collector. To this end, it is fitted with a pipe system, which - similarly to reinforced concrete ceilings – can be thermally activated.
What does sustainable construction cost?
At a total cost of €1.983 million, the 31-person office building is cheaper than some luxury homes. However, it is interesting to compare the cost of the solutions selected with a more ‘standard’ building according to the EnEV: the FNR reports additional costs of €62,000 (4% of the total). One of the main reasons for this was the floors and ceilings (board ceiling, fibreboard insulation and the goat-hair carpeting). The ‘energy-related’ additional costs – what was spent to undercut the EnEV rating by 50% - were 12%, with 5% going on the building construction and 7% on the systems engineering. Particularly costly here was the central ventilation system with heat recovery, which costs around seven times as much as a comparable solution according to the EnEV standard.
A detailed brochure about the new FNR building is available free of charge on its website (in German): www.fnr-server.de