Millar + Howard Workshop

Dursley Treehouse

Built on a small plot in the centre of Dursley, this house was designed to have minimal impact on the surrounding trees and to preserve the natural habitat of the site. Featured on Grand Designs in September 2016, the Treehouse garnered much interest for its beautiful cantilevered structure, its low environmental impact and for the romanticism of living in a ‘treehouse’.

dursley-treehouse-millar-and-howard-workshop-1The brief for the house was to gain planning permission for this unusual site which had twice before been refused planning for conventional houses. The client wanted a dwelling that was very sensitive to both the immediate surroundings of the site and the wider, local community. The client was also adamant that the impact of the house on its site should be very low and be as environmentally sound as possible.

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The 27 protected trees posed a big constraint and dictated the location of the building within the site. In order to protect the tree roots, (a condition of the planning approval) the ground had to remain untouched, therefore an elevated building was proposed. This meant that at the design conception stage the trees had to be considered in three dimensions in order to accommodate all the branches and predicted growth and the architects, together with the engineers Millar + Howard Workshop had to think innovatively to solve the unusual implications produced by this design.dursley-treehouse-millar-and-howard-workshop-2Millar + Howard Workshop wanted to design a structure that was distinct from the trees yet complimented their form, textures and patterns, a building that differed from a typical treehouse. Keen not to recreate a woodsman’s hut or a chalet, they drew inspiration from projects like the Juvet Landscape Hotel in Norway. By proposing a design that highly contrasted with its surroundings but didn’t distract from them, they allowed the building to become part of the wood and the shadows that the trees create.

This complex building has galvanized steel piles (avoiding tree roots) instead of concrete foundations. The main structure of the house is a double stud timber frame with 300 mm of insulation. This then sits on a steel frame which itself sits on screw piles designed to keep ground disturbance to a minimum. Specialist forklifts and cranes with caterpillar tracks were used to keep pressure on the roots to a minimum.dursley-treehouse-millar-and-howard-workshop-3The building is clad with untreated Larch cladding. Many of the internal and external finishes were reclaimed, including the metal galvanized grills for the bridge and some of the galvanized balconies which were sourced from a disused factory in the town. The two lower floors have a slate floor reclaimed from an old Rolls Royce garage and the upstairs floor features floorboards from an old basketball court. The house also features its own water supply reducing the carbon footprint further.

Images © Jon Martin, Tomas Millar