Balancing emerging technologies with a ‘salvage where practicable’ ethos, the Green House project turned an expensive to heat rural 1960’s built detached house into an economical home for couple who take environmental responsibility seriously.
BBM were charged with turning a 1960’s gas-guzzler into a low energy lean green house. Clients Nicholas & Heather moved to Sussex from an award-winning (RIBA 2005) new dwelling named Cob House. They understood the many complicated issues associated with genuine sustainable design, but also wanted to transform this rather non descript 1960’s house into something aesthetically less ‘challenging’.
BBM’s strategy was to salvage as much of the existing building fabric as possible, while transforming the aesthetics of the property internally and externally (there is a minor south facing extension to the new dining room forming a first floor sheltered balcony off the master bedroom), as well as drastically reducing the building’s ‘ecological footprint’.
BBM took advantage of the’ thermal mass’ of the existing brick cavity walls by over-cladding them externally with 140mm of timber fibreboard insulation finished with locally-sourced sweet chestnut rain screen cladding. The original ground floor maple floor was carefully removed and used to form the new kitchen units (the original units being use for the clients new dark room), while the floor was finished with a polished concrete made with ‘green’ concrete using 60% less conventional cement. 400mm of sheep wool insulation was used in the existing roof voids.
The main staircase was rotated about 180 degs, its primary steel structure reused and clad with new chestnut treads and balustrade. Existing PVCu windows were removed and either sold or given away on ‘freecycle’. They were replaced with high performance double glazed windows and doors. Barely anything when into skips and therefore landfill. Rainwater is harvested and used to flush wc’s and water the extensive vegetable gardens.
The house originally relied on oil to fire its boiler. BBM replaced this high-energy system with a ’carbon neutral’ biomass boiler firing the hot water and central heating system (under floor heating to the ground floor and radiators upstairs). This system is supplemented by a 4msq array of solar thermal panels on the south facing roof. The boiler is predicted to be required only for about three months a year. The external fabric is so well sealed (tested at only 5 air changes per hour), and insulted (typical wall ‘U’ Values at 0.14) that the house can rely on heat given off by the occupants, fittings, solar gain etc to keep it comfortable for most of the year.
From an energy point of view the resultant house performs to ’Level 5’ of the Code for Sustainable Homes – an amazing achievement for an average 1960’s dwelling.