24 May 2010, 9:00 PM
A unique zero carbon house has been built in inner city Birmingham, to meet the stringent requirements of Level 6 of the UK Code for Sustainable Homes. Itís an eco-house that will produce at least as much energy as it consumes, and itís been built around an existing house! The house is the winner of an RIBA award for architectural excellence in 2010, and will be featured in the Summer 2010 edition of Green Building Magazine.(Volume 20 no.1)
Designed by John Christophers of Associated Architects as a family home, the ground-breaking carbon-neutral building is now being lived in. Itís an extension of a redbrick Victorian house, converting a 2-bedroom semi-detached into a 4-bedroom dwelling with a studio loft. It extends upwards and outwards: upwards to catch the sun otherwise obscured by a taller neighbouring house, sideways for more space. The original 1840 brick house is preserved, as are the mature ash trees in the garden. Integration with the surroundings is important, and the design takes account of the neighbouring architecture.
The design conforms to Level 6 (the highest level) of the new Code for Sustainable Homes. Itís not the first Level 6 house under the sun, but itís arguably the first in the UK to incorporate an existing building, and may be the first to be lived in. Architectural flair, user-friendliness, and a pleasing living space are as much a part of the design as the demands of the Code.
Some of the features which enabled the house to reach CSH level 6 are - thermal insulation: the new roof and walls will be 20 times better insulated than the existing ones: Airtightness: sealed to a level 28 times better than existing, but retaining vapour permeability to stop condensation. This includes using a special membrane in the walls. Research has shown that limiting warm air leakage, even through concrete walls, is an essential element of radically reducing heating needs.
The windows are triple glazed, being 12 times more insulating than the current windows. Heavy construction: thermal mass keeps house warm in winter and cool in the summer.
Passive solar: carefully oriented glazing to provide winter solar gains. Summer shading with the existing ash tree.
Low-energy lighting and A++ fittings to minimise electricity use, including an electric cooker with induction hob.
Solar roof: photovoltaic (PV) panels will convert the sunís energy into electricity and any surplus can be exported to the national grid. This offsets the electricity that will imported (for example at night).Solar hot water: roof panels use the sun to heat hot water, stored in a large cylinder.
Ventilation system: supplies fresh air warmed by recovering 95% of the heat from extracted stale air. Another essential element in preventing heat loss.
Wood-burning stove: top-up space and water heating fuelled by wood from the garden. The heating needs are so low that prunings from 2 large ash trees will be sufficient. The regrowth of the trees captures the carbon dioxide emitted by the stove.
Described as a milestone in the history of eco-homes and energy-efficient buildings in the UK Ė seven years ahead of the government target, which decrees that all new homes should be carbon-neutral by 2016. Its creators see it as a contribution to the groundswell towards green lifestyles and the enjoyment of a sustainable way of life, in the shadow of global warming caused by human emissions of carbon dioxide and other greenhouse gases. Itís designed to protect the environment and enable its occupants to enjoy the environment.