‘eco’ extension
balmullo, fife
The brief for this project was to add a new flexible garden room to an existing 19th century stone built cottage.
Flexibility was a key design driver as the room was to have the potential to be used as a guest bedroom or even an independent bed sitting room in future.
The client placed great emphasis on sustainability which gave us the opportunity to explore many energy saving technologies and construction methods. The technologies included; on site electricity generation with a wind turbine, solar water heating panels and construction methods included timber frame, traditional cavity masonry with insulated render and ‘Thermoplan’ blocks.
The completed extension appears fairly traditional in form and materials sitting easily beside the existing cottage without resorting to a pastiche imitation of the original cottage. Clay roof tiles were used to match the existing house and a white insulated render finish was applied to the exterior walls. Although traditional in appearance, the external walls of the extension were constructed with 300mm 'Thermoplan' block a new extruded clay block designed to achieve high levels of insulation & thermal mass while minimising the impact on the environment during their manufacture. A wood fibre insulation panel is then fixed to the wall prior to rendering to achieve a U-value of 0.20W/m2K, the walls are 'breathable' and have very high thermal mass which helps to retain heat in winter and will stay cooler in summer. The roof is insulated with recycled cotton and hemp and wood fibre and achieves a U-value of 0.16W/m2K.
The eventual solution relies on passive solar gain, high thermal mass, natural ventilation and high levels of insulation to maximise energy efficiency and comfort while minimising environmental impact.