The Stadthaus/24 Murray Grove is a new nine-story multi-family residential building in Hackney, East London. Completed in 2009, it is the tallest building in Europe structured entirely of wood. It illustrates a ground-breaking approach of building material selection that can help achieve carbon-neutral (or even carbon-negative) buildings with current technology.
Because there was no precedent for such a tall wooden building in the world, a great deal of testing to prove the material’s fire-resistance, structural and acoustical properties was required before authorities would allow the design to proceed. Building codes in the U.S. will allow wood buildings only six stories in height at this time, but this method of building is applicable to low-rise buildings as well.
Murray Grove contains 29 apartments. It is built of solid slabs of timber, used for floors and walls, with no other structural framework. Much like plywood, but on a larger scale, the slabs are made of layers of solid 1” thick boards, cross-laminated into large slabs up to 30 ft. long. These are quite strong and resilient, and the solid construction offers excellent fire-resistance and acoustic separation properties, compared to more typical hollow “stud” walls.
Wood is a renewable resource, of course, and all of the adhesives and chemicals used in the manufacture of this system are non-toxic. Compared to conventional steel and concrete construction, embodied energy was reduced an equivalent of 340 tons of carbon emissions. This calculation allows for the fact that the panels were manufactured in Austria and transported to the project site in England. Unfortunately, there is not yet any manufacturing source in the United Kingdom. Ideally, the building would be made of lumber from Scotland, reducing transportation and further reducing the embodied energy.
In addition, approximately 200 tons of carbon are “locked in” the wood material, which alone is equivalent to the energy that will be used to heat, cool and operate the building for twenty years. Based on that alone, the building will have a negative carbon footprint until almost 2030!
This building represents sound material decisions based on life-cycle analysis. Wood is biodegradable, so “cradle-to-grave” consequences are relatively benign. Add the fact that the wood slabs will easily disassembled for some re-use when the day comes for its demolition, we see that “cradle-to-cradle” thinking has been included.
The exterior cladding of the building consists of fiber-cement panels, made from 70% wood-waste products.
Perhaps most surprisingly of all, the developer of the building was easily convinced of the unusual choice of building material – the architects reported that the proposed construction would be faster, simpler and less expensive than conventional steel construction. The entire wood structure was assembled by 4 workmen in only 27 days!
Courtesy Waugh Thistleton Architects Ltd.; photos courtesy Will Pryce