Have ‘Zero Carbon’ Homes come of age? - 02

Recent spikes in energy prices and concerns over the imminent threat of global warming are making opting for zero carbon housing an increasingly more attractive alternative. What exactly is a zero carbon home?

Basically, a "zero carbon" home is one which generates more energy than it uses over a set period of time. A building's "carbon footprint" is calculated over the full life of a property, taking account of carbon dioxide generated in its construction and subsequent use. This means building a highly efficient, super-insulated home from sustainable, environmentally friendly materials to minimize CO2 (carbon dioxide) use. These homes should ideally be self-sufficient in all of their service demands; operating independently of public utilities, such as the national grid, sewage treatment and water services. They may employ sustainable technologies such as rainwater harvesting and grey-water treatment. A "zero carbon" build is usually achieved by offsetting any CO2 produced through the use of small scale renewable energy generation. This means including technology such as properly sited wind turbines, solar panels, extensive glazing to take advantage of natural light and passive solar gain, photovoltaic cells and geothermal heat pumps. Excess production of "zero carbon" renewable energy can even be sold back to the national grid, resulting in zero net carbon emissions.

Why would I want to build one?

There are many benefits to embarking on a zero carbon build, the most obvious being its running costs. These buildings must be highly efficient, with air tightness and especially insulation standards far in excess of current building regulations. To reduce heat lose, a heat recovery ventilation system is required, to help circulate clean, fresh air, avoiding the formation of mould, also benefitting allergy sufferers. If implemented properly, the combination of energy efficiency, micro-generation of renewable power and super insulation in a zero carbon home will lead to massive reductions in utility bills, and ultimately, if energy is sold back to the grid, no bills at all.

Is it expensive?

This is really a matter of opinion; for a new build, initial costs are indeed significantly higher. However, taking into account whole life costing of the building and the savings to be made on utility bills, this may be no more expensive than a traditional, less efficient build. Furthermore, increases in the number of people investing in green building technology and eco-housing are making it an increasingly more affordable option, lowering initial costs.

Would there be grants available?

This is also a matter of future-proofing your home - Gordon Brown has already pledged that by 2016, all new homes will be "zero carbon" and has indicated that further legislation is in the pipeline. As an incentive, all zero carbon homes built up until 2012 to a value of £500,000 will be exempt from stamp duty. Zero carbon homes over that value will see a £15,000 reduction in stamp duty fees. Achieving such high levels of energy efficiency can be a complex process; however an architect will be able to provide you with advice on how to construct your zero carbon home.