The official definition of what constitutes a zero carbon building is eagerly awaited by developers and designers alike

The need for a definition first became apparent in 2007, when the government announced all new homes would be zero carbon by 2016, and again in 2008 when it declared its “ambition” for all new non-domestic buildings to be zero carbon by 2019.

Industry had its opportunity to help shape this definition during the consultation process, which finished in March. The consultation document proposed adopting the UK Green Building Council’s suggestion of a hierarchical approach to achieving zero carbon. Making a building as energy efficient as possible would be the first step, followed by meeting a minimum level of carbon emissions using on-site solutions. The third stage would be the option of using off-site “allowable solutions” to achieve the emissions target, such as investing in an off-site wind farm or exporting heat from a CHP.

The success of the definition will depend on how workable the third stage is in practice. The planning system is complicated enough; get it wrong and the definition will lead to costly delays in gaining approval as designers and planners wrestle with the bureaucracy of demonstrating compliance.

A more practical idea is being promoted by Fulcrum Consulting. Rather than going for the allowable solutions, the firm proposes the creation of a community infrastructure fund so that once the cost of going beyond stages one and two becomes excessive, developers could pay into the fund as a way of mitigating emissions. This locally administered offset fund could then be used to provide large, high impact, community infrastructure projects. However, the government appears to have ruled out this proposal.

Perhaps the true answer lies not with buildings but in tackling the country’s energy supply. Rather than trying to turn buildings, directly or indirectly, into power generators, the government should focus on creating a low-carbon electricity supply. Provided a suitable feed-in tariff exists, this would not exclude building renewables but would lead to their application when it was cost-effective to do so – an economic balance of on- and off-site solutions would emerge. Not only would green electricity help create sustainable new buildings, but it would also help cut the carbon emissions of the existing building stock – and that’s most important of all.