Policy 5.2 of the London Plan requires every major development proposal to submit a detailed energy assessment with the planning application. A failure to do so will probably result in the planning application being rejected.
That’s not really anything new, but what is new is that London’s Mayor is applying a zero carbon standard to new residential developments. This means that any development needs to achieve at least a 35 per cent reduction in regulated carbon emissions over and above Part L 2013 onsite. Given that the current Part L standards are actually quite good in terms of energy efficiency, that’s a massive increase a building’s energy performance. To get all the way to zero emissions, the remaining carbon emissions are to be off-set through a cash in lieu contribution to the relevant borough which is to be ring fenced to secure delivery of carbon dioxide savings elsewhere.
The London Plan makes it quite clear that the overall aim is to be building zero carbon buildings by 2050. In order to achieve this, the plan proposes the following model:
The approach is sensible as it has been recognised for some time that the fabric first approach is the way to go. But the criteria are challenging and thus it’s quite tough to achieve the levels needed, as the existing Part L is, in itself, quite stringent. The GLA has taken care to avoid the pitfalls of certain other schemes which were seen to be an exercise in ticking boxes, rather than delivering real, measurable improvements.
The detailed assessment methodology is simple, well thought through and can be found here.
The emphasis on demand reduction  precludes the usual bunging of a bit of PV on the roof, just to comply. If done correctly and at the right time, however, improving the fabric can be the cheapest form of compliance provided that these measures are incorporated into the design early enough. We find that the reason fabric measures end up being more expensive is that they are included at the last minute, simply because the energy assessment gets done just to comply with planning. If the assessment becomes integral to the building process, just as, for example, the structural assessments, the output is taken into account early and there is time to adjust the design accordingly without incurring significant additional cost.
The GLA has buttoned down the cash-in-lieu payment, so it will be difficult to avoid if your development genuinely can’t achieve the required reductions. An assessment that therefore focuses on minimising or avoiding the cash in lieu payment altogether is clearly the best option – either way you’ll be spending money, so it may as well be invested in the development for the tangible energy-saving payback you’ll receive, whether upon sale with a higher valuation, or throughout the lifetime of the building.
At Enhabit we think that the London Carbon Plan is an opportunity for our industry to demonstrate that low energy building achieves multiple aims that are aligned with those of the developer – i.e. high quality, low energy buildings, with great living environments that are delivered on budget. To achieve this we need to work to better integrate energy design within the concept design so we can deliver resilient, high quality, controllable and comfortable environments that buyers are proud to live in and that developers can afford to build!
 The assessment requires the applicant to demonstrate how the demand reduction measures alone meet and exceed building regulations.