A five-bedroom house built in Aberdeen has achieved the ultimate energy efficiency aim of removing the need for space heating. Designed by architect Gokay Deveci, the 'zero heating' house has been built without a dedicated space-heating system, its only concession being the provision of a small wood-burning stove for use in emergencies.This offers a peace-ofmind standby for the occupants in case of severely cold winter weather conditions.
The building uses materials from recycled sources, which, together with innovative heating and insulation, has reduced the build costs for the house by up to 20 per cent in comparison with a similarly sized rural house (traditionally constructed in rendered block/block construction with a tiled roof ).
The construction cost, including kitchen and bathroom fittings, was £60,000 for a total floor area of 127m 2(see table below). Capital savings are even greater in comparison with conventional brick/block construction and these savings do not take into account the cost-efficiency of the building in use.
Analysis A research exercise completed by the Scottish Centre for Environmental Design at Robert Gordon University has analysed building costs over a projected 60-year lifespan. For a conventional house type, it has been calculated that savings realised in initial capital cost, energy running costs, operation, disposal costs and residual value, amount to as much as £40,000.
Even compared with similar types of environmentally friendly buildings, which do not have the zero-heating house's solar panels and high level of insulation, at least £10,000 can be saved over the same period due to better energy efficiency standards.
The research study indicates that there will be a projected 2 per cent increase in the cost of material maintenance.
The floors and walls comprise Masonite I beams - timber webs with softwood flanges - which have the benefit of being lighter and with a better load/span capacity than timber joists and studs of equivalent dimensions. (A 200mm standard beam can span up to 12m. ) The building is insulated with Warmcell - a blown-fibre, recycled-newspaper product - to a depth of 300mm in the walls and 450mm in the cold roof.
Argon-filled, low-E, triple-glazed windows are used to complement the very high insulation levels of the walls and roof, providing a U-value of 0.1 and 0.11 respectively. A SAP rating of 120 has been achieved by the elemental method.
The lack of a dedicated heating facility means that all the heating needs of the house, as far as possible, will be derived from internal gains such as the occupants' body heat, lighting and cooking, as well as solar gain.
To facilitate this, the house incorporates:
mechanical heat-recovery extract units;
super-insulation and excellent airtightness;
passive solar design and high thermal mass.
Best option Externally, the house is clad in locallygrown Scottish larch with clay tiles used for the roof, both of which are sympathetic with the house's immediate surroundings. It also offers the best option for a designated 60-year life cycle. Both roof and cladding are recyclable.
The cost savings on the structure have been realised through intelligent design which utilises a very simple, geometric plan to maximise the space/envelope ratio.
Further savings have been delivered through the modularisation of the lightweight structure and the centralisation of living space.