The goverment has bought out a new technical guide to clarify the code for sustainable homes, but it still has gaps

From the 1st May all new homes in England and Wales have been required to be rated against the Code for Sustainable Homes (CSH). Note this word ‘rated’ – it’s important. It doesn't mean the same as ‘assessed’. An assessment is a full calculation of the CSH score for the home. A rating, however, could be just such an assessment, but it could also be a “can’t be bothered” kind of alternative, whereby a developer issues a ‘nil rating’ certificate which simply says that that the property has not been assessed. It is difficult not to see this as a major missed opportunity.

Mid-April saw the much needed release of the third version of the Technical Guide in just over a year. This didn't contain any technical enhancements as such – it was just intended to help industry by correcting some errors and providing more information. However, given that the Code helpline has been hit with a wave of queries it would seem that it has possibly caused more confusion. True, there are additional definitions and explanations which are helpful, but also hidden within the 57 extra pages are lots of small changes only some of which are highlighted for the reader. The department for communities and local government [CLG] say that there is another document detailing the changes – but this is not currently on their website.

The well-known loophole on the use of direct electric heating has been closed (by making gas heating the base case), but puzzlingly we hear that CLG are already planning to reverse this decision. As it happens, this was only a theoretical loophole, involving the use of solar water heating. Direct electric heating in housing is likely to be difficult to market, and it is very difficult to fit solar water heating to individual flats. So perhaps this is why CLG didn’t, after all, think it a loophole worth worrying about.

The issue about the Code favouring larger dwellings remains, but is arguably not ‘an issue‘ (in the negative sense) at all. The effect only really appears if you throw the wrong solution at the wrong problem. In detached houses it is right to concentrate on good insulation since there is a lot of heat loss, whilst in mid-terrace town houses and flats (using communal heating) addressing the hot water makes much more sense since that is where the carbon emissions come from. This effect has been hotly debated by the techies in our industry, and the most usual conclusion is that the alternatives have bigger problems.

Worryingly, though, there are new errors in some of the detailed technical requirements. This may sound picky but it is a technical guide after all. In one place we are told that a percentage of the total emissions must be offset by renewables, but elsewhere to ignore the emissions from appliances. In another place we are told firstly that energy efficiency measures help reduce the contribution required from renewables but then we are told that these don’t count. And on another page we are given the wrong figures to use in the calculation. Air-source heat pumps have been deliberately removed as a heating system, but we now understand that this was a mistake; how did that happen?

In principle, one can excuse the continued tweaking, redrafting and clarification that has been necessary. After all, any really worthwhile policy will inevitably be a complex one, and the finer points will only come out as the policy enters use. But there does seem to be a rather high level of “just sheer careless” mistakes still appearing.

CLG must surely see that industry is keen to get going. Never before has the house building industry been so positive about higher environmental standards. There will clearly need to be another revision of the Technical Guide, and we urge CLG to review what has gone wrong this time, not rush things and not be pressured by political deadlines. A really robust guide is what industry needs now, to enable it to help deliver the government’s noble aspirations for truly sustainable homes.