Sustainability Rating Tools

I participated in an interesting debate during the week at Derwent’s White collar Factory, chaired by the UK Green Building Council. The topic was ‘whether we need rating tools to advance the sustainability of the built environment’. I took the opposite view, more from the need to create a debate than from conviction, but as always, taking the contrary view was helpful to crystallise my thinking about what a sustainability rating tool should be rather that what they currently are. This is all very relevant to the current situation where DCLG seem intent on abandoning the Code for Sustainable Homes without consultation, and without replacing it.

My thoughts on sustainability rating tools are that we need them but we could do with some better ones than the ones that we currently have. In case you are not sure what rating tools I am talking about here is a list of the ones that we at HTA currently employ on one project or another. BREEAM New Construction, Code for Sustainable Homes, EcoHomes, ActiveHouse, BREEAM Communities, and a couple that we have developed ourselves: we also use energy assessment tools that some people think are sustainability tools but aren’t, like SAP, SBEM and Passivhaus, all of which suffer from the same problems as sustainability rating tools. The main problems that I have with the current crop of tools that we use are as follows:

-I don’t think that rating tools should tell professionals how to do their job. They are paid enough to know that already, and there are many mechanisms in place to spread best practice, there is no need for rating tools to do that job.

-Rating tools generally focus too much on environmental criteria to the exclusion of financial and social, and this is a big mistake. Ignoring the financial impact of measures is what has led to the Code to be on the verge of being scrapped. Housebuilders see it as adding costs but not adding any value. Their view is that Code homes don’t sell for any more than any other home, so there is no benefit to house-builders in following it. Government pays more attention to them because they have a big impact on the economy. If the Code was seen to be making new homes more attractive to purchasers, or attracting a premium value, then there would be no argument about applying it. We need to join up the thinking between environmental, social and economic sustainability.

-Rating tools tend to be written by a narrow group of people, mainly those with a strong interest in environmental matters, which leads to a narrow focus of credits and measures. Tools need to be relevant to a wider section of society and encourage high quality design that takes into account the needs of the wider population.

-The costs of running the tools and the frequent costs of retraining all need to be lower. These costs are a barrier to entry and don’t help to get tools more widely used.

-The assessments carried out using the tools tools should not need to be verified independently. Professionals are paid to do a job, and they should do it properly. A proportion of assessments should be independently audited, and poor assessments should have the rating taken away from the client. This would improve quality and lower the costs of carrying out assessments.

-Tools must look at the building a year after occupation and assess whether measures are working or not. We don’t have the luxury of continuing to install equipment to meet the requirements of a rating tool when we know that the new tenant/owner will come in and remove them. If the measure isn’t working then the tool needs to change immediately, not years later.

-Finally, rating tools should focus on the outcomes, and not on the process. Targets should be set that are measurable, and the project team should work out how best to do the work. Targets such as Fabric energy Efficiency, CO2 emissions, sound reductions, daylight factor, space per occupant, embodied energy per occupant, air quality, occupant satisfaction, hours of overheating, and so on are all measureable and there are tools or processes available to do this. I use the ActiveHouse manual as an example. Its less than 10mm thick and contains all the elements of a good rating tool. That doesn’t make it easy to meet it, but it does make it possible to understand it.

Hmmm, maybe I should write my own…


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