I attended a roundtable hosted by the NLA last week on Zero Carbon housing in London. The purpose was to discuss the issues around zero carbon, whether the current definition is appropriate in London, and how to develop policy in this area. The event was well attended by housing consultants, with the NLA, Zero Carbon Hub and DCLG represented.
It was interesting to hear that little analysis has been done to date on the impact of the new definition of Zero Carbon on housing projects over four stories. The current definition is aimed primarily at the housebuilder market who mainly develop suburban sites, rather than on developers who bring denser urban sites to market. DCLG and the ZCH acknowledged that there is a piece of work to do on assessing medium and high-rise dwellings.
The likelihood is that the Fabric Energy Efficiency Standard will not be difficult for higher rise buildings because of the inherent efficiencies in building more dense developments. But achieving Carbon Compliance will be much more difficult because the use of PV as a proxy for CO2 reductions will not work in this context. The ratio of roof to floorspace won’t be high enough.
There was a lot of discussion about the potential for district heating schemes to fill this gap, some were in favour, and some against. There was some realism from the engineers present, acknowledging that some district heating schemes have an efficiency of only 30%. This may be caused by poor design and implementation, and would change dramatically as such systems proliferate. But the problem is that there is no sign that these systems will proliferate, they are simply too expensive in capital terms to be viable in the current market.
The alternative which was discussed at length, is the upgrading of the existing housing stock. In London there is a huge backlog of poorly performing dwellings that need energy efficiency upgrades and the Allowable Solutions monies coming from new development in London could be pooled to fund these upgrades. A likely figure for the monies available is £1500 per new dwelling after 2016, and if London achieves a target of 30,000 units per year, this could deliver £45M of annual funding. This could pay for 4,500 external wall insulation retrofits per year.
While it may be chickenfeed in the context of the Green Deal it is still worth doing, and worth delivering guaranteed emission savings, immediately. That is worth having.