What now for the Code for Sustainable Homes?
Up until now, the Code for Sustainable Homes has been a nationally agreed yardstick for comparing the ‘sustainablility’ and energy efficiency of houses. Such a yardstick is essential, but changes are afoot…
In a previous post I talked about the 2014 Code for Sustainable Homes addendum, which carries forward the Code for English sites and details how to apply it for new projects under L1A 2013. In Wales, the Welsh Government announced this month that they will be winding down their Code requirement, set out in Technical Advice Note 22 (TAN22). From 31st July, new Wales specific versions of the Part L Approved Docments will be coming into force, incorporating the previously required 8% improvement over L1A 2010 requirement (from TAN22), into the new targets. The Building Regulations Approved Documents set minimum standards, but do not cater for going further than the minimum, which at times results in houses being built to comply, rather than necessarily being built well.
The Welsh Government is also developing “guidance on sustainable buildings which will further advise developers on integrating sustainable building design principles into their proposals” and design advice will be laid out in an amended Technical Advice Note 12 (available from 31st July) to include information on the energy hierarchy, allowable solutions and sustainable building policies for Wales.
BRE’s Code Successor?
In the wake of the Housing Standards Review and with the winding down of the existing Code as something that Local Authorities can require as a condition of planning approval (both in England and now in Wales), the Building Research Establishment (BRE) have announced that they are looking to develop a successor to the Code that developers and builders can choose to follow, in order to differentiate their product from less sustainable and less efficient ones.
The BRE want the replacement standard to recognise performance beyond minimum regulation and for it to provide increased quality and choice for the consumer.
Their vision is that:
“The new standard will be developed for the UK and international markets and can be adapted for specific local circumstances. It will use an easy to understand, consumer focused rating system. It aims to tackle the performance gap issue, ensuring that the home is performing as designed and if not to recommend a course of action the home owner can take.”
They are seeking views as to what the replacement standard might include, with a 25th July deadline for responses.
So, what could be incorporated into a successor to the code?
1. A means of showing higher on-site performance would be welcomed.
What has to be done on site, before allowable solutions kicks in for ‘Zero Carbon’, is to be limited to 19% better than L1A 2013 levels (i.e. CfSH Level 4). Arguably one thing that the Code seriously lacks is any further performance levels in between Code 4 (19% of the way to zero from current level) and Code 5 (all the way to zero), so some interim energy efficiency levels might be a good start.
2. Higher standards of building fabric performance on site should be rewarded.
Reducing energy consumption in the first place is important. There’s a simple cost argument from a home buyer’s viewpoint for more energy efficient homes to be built, as reducing energy use reduces energy spend. Lower energy consumption also reduces carbon emissions by reducing the amount of fuel used for heat and power and, with carbon emissions linked to climate change, there’s also a strong environmental case for using less energy.
3. Embodied Energy
Embodied energy/carbon of materials might be incorporated, if so then a standardised approach (crade to grave – whole life cycle analysis) should be adopted, to best cover the full picture. There are too many conflicting values being claimed in the market, with ‘cradle to gate’, ‘cradle to site’ and ‘cradle to grave’ being erroneously compared with one another, with the first two not covering the full picture and sounding better as a result.
(Environmental profiles measure the impacts of construction materials, products or building systems throughout their life – not only during manufacture, but also over a typical building lifetime (This includes lifespan of products and any potential repair or replacements that would be required over the buildings lifespan)).
Sustainability of materials under the code doesn’t currently take account of the Green Guide ratings of insulation products, only the rest of the construction materials; however many products do have green guide ratings for BREEAM purposes, so these could be incorporated.
4. Responsible sourcing of materials
As well as embodied impact, responsible sourcing of construction materials might be considered, with credits to be gained from sourcing products from manufacturers following appropriate high standards e.g. BES6001.
Overall, there is an opportunity in developing a replacement standard, for us all to look at sustainability in new dwellings more thoroughly; however, a balance needs to be struck between detail and accessibility, with one eye on engaging the consumer and clearly explaining to them what is being compared and why.
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