May 2009

One Planet standard vs LEED and the Code

The One Planet programme is not trying to create a certification scheme for developments akin to LEED or the Code for Sustainable Homes- the aim is about helping to create a network of exemplars that are 'measurably' sustainable. Clearly though to avert dangerous climate change we will need to developers and companies to start operating in this way - so there is a need to highlight the gap between what is currently being promoted as 'sustainable' and what is actually needed to bring our consumption levels under control.

As part of this BioRegional have been comparing the carbon emissions of residents living in neighbourhoods built to best practice standards in the UK and the US, with the probably and possible emissions in One Planet Communities. Taking the specific examples of SOMO and One Brighton the analysis highlights the increased savings that are achievable when looking to influence behaviour as well as design, as well as the huge challenge in actually getting CO2eq emissions down to less than 1 tonne per person per year.

What these scenarios show is that the purely building efficiency approach, as promoted by the Code for the Sustainable Homes in the UK, can only deliver a GHG saving of less than 25%, even in zero carbon buildings. The LEED ND approach which also aims to reduce car dependence, but is less strict on housing emissions could deliver a 18% reduction in emissions, but from a higher baseline. Whereas in the two case studies presented here, which aim to influence behaviour through physical measures (little or no car parking space), service provision and incentives the savings, the savings for an average resident could be increase to 35-55% and for a keen resident up to 50%.

This analysis shows that while the building and neighbourhood efficiency models being promoted by the Code for Sustainable Homes and LEED certification schemes are clearly part of the solution, there is still a huge gap between the savings that they will deliver and the savings that are required. Yet as shown in the two case studies there is the potential for the design of new homes and communities to significantly influence people's behaviour and therefore their emissions.

Plugging this gap in what the best new construction is, and could be, delivering in terms of carbon emissions, needs to be a priority area for government's looking at meeting emission reduction targets. While this may be politically challenging (suggesting lifestyle changes are required is a much less appealing message than suggesting technology and efficiency alone can avert climate change) it is absolutely necessary if significant reductions in greenhouse gas emissions are going to be made.

The nature of how this is done is likely to produce much debate - as it is questionable that the certification schemes aimed at driving building efficiency can easily be applied to lifestyle strategies; and so a more flexible approach may need to be taken. In the mean time the construction industry needs to watch and learn from the pioneers who are already designing their buildings to influence behaviour, and then start to follow suit.