By Andrew Bickerdyke, Director, and Paul Jones, Director, Ramboll UK
In 2007, the seventh and final Harry Potter book was launched, selling 2.7 million copies in the UK and 11 million worldwide in the first 24 hours, and so becoming the fastest selling book of all time. With perhaps a touch less publicity, at the start of March this year, the 2021 revision of the London Plan was formally published.
Although not quite generating the same fanfare as Harry Potter and the Deathly Hallows, the revised version of the plan nevertheless formalises the updates to London planning policy for the next few years. While the details of Potter’s final battle with the Dark Lord remained a closely guarded secret until the point of its release, the new version of the Plan has been available since December after a long process of consultation and revision; somewhat dampening the demand for midnight queues at City Hall to grab a copy.
So, from a buildings point of view, what does the new plan have in store; where does it succeed, and where does it miss the mark?
Net zero
In a welcome move, the new version of the plan reaffirms the intention to move London towards being a zero-carbon city by 2050, requiring all new developments to reduce carbon emissions in line with the energy hierarchy.
The basis of this will be familiar to anybody from previous versions of the Plan. Developments must achieve a 35% reduction in carbon emissions against Part L and offset the residual emissions to meet the zero-carbon target – so far, so familiar. However, whereas previously the net-zero requirement applied to residential buildings only, it now applies to all major developments; a major step forward and a welcome firming up of policy.
Be seen
The new version of the plan also formalises the new and additional stage of the energy hierarchy, ‘Be Seen’. The issue of the ‘performance gap’, the difference between a building’s predicted and actual performance, is well known and not peculiar to London. The new step requires developers to monitor, verify and report on the energy performance of new major developments.
This is a major step forward in closing the performance gap and will help expose deficiencies in the design and implementation of heat networks.
At the design stage, this must be underpinned by a TM54 analysis of regulated and unregulated energy use, to allow comparison with actual use post construction. Perhaps in a tacit acknowledgement that they could have gone beyond this, developers are encouraged to go a step further and submit, as part of the planning reporting process, a DfP target base building rating instead.
Perhaps the Greater London Authority (GLA) is saving the mandating of this for future revisions of the Plan, but as the GLA’s guidance itself acknowledges, the similar NABERS scheme has been transformative for building energy performance in Australia, which raises the question – why couldn’t it be for London too?
Emissions offsetting
In a further positive move, more flexibility is now allowed for offsetting residual emissions. As well as making payments to a borough’s offset fund, emissions can now be offset offsite where an alternative proposal is identified, and delivery is certain.
This could allow a developer or housing provider to upgrade the performance of their existing building stock to offset the emissions from a new scheme…cue some interesting discussions with the LPAs to convince them of this approach. Being able to demonstrate ‘additionality’ will also be key.
Heat networks
The push towards heat networks has been baked into the London Plan since 2008, and in 2011 was extended to include the ambitious target that 25% of the heat and power used in London would be generated through local decentralised energy systems by 2025.
This policy remained included up to the 2017 version of the plan but is now being quietly dropped; one assumes this is because, four years away from the target date, it was a policy that could never be achieved – the dead cost of installing large energy networks, particularly in existing crowded streets, all too often made them unviable.
The spirit of the policy does, however, live on, and developments are still required to connect to heat networks wherever possible. Experience suggests this is often at the detriment to better on-site solutions. Maybe the next revision will see the policy culled altogether.
Energy storage
Notably absent is a mandate on energy storage. Whilst large scale battery storage is likely to remain prohibitively expensive for now, designers have been getting used to incorporating thermal storage into heat networks. In the past the objective has been to maximise running hours of CHP plant. In the age of heat pumps, correctly sized thermal storage is more critical than ever, to avoid oversizing power-hungry heat generating plant to meet peak demand.
Mandating this through the planning process could be a useful mechanism to force the issue.
Circular economy
For the first time, we are seeing the requirement to assess a scheme against the principles of the circular economy; with referable schemes required to submit a ‘Circular Economy Statement’ setting out how a new development will reduce material demands and enable building materials and products to be reused at the end of their life. Pre-demolition audits are now a requirement to assess the potential for repurposing existing structures and the re-use of any existing materials on site.
Detailed standalone guidance was published in draft in September 2020 and the requirement to prepare the statement will encourage many to adopt circular economy principles where once they may have not. However, the Plan falls short of setting explicit targets that a scheme must meet. Is this one for the next revision?
Whole life carbon emissions
Another new introduction for 2021 is the requirement for referable schemes to calculate the whole life carbon emissions for a building. This means that new buildings must now assess all emissions associated with a scheme, including unregulated energy use, construction emissions and embodied carbon.
While this is undertaken via assessment at the design stage, critically and positively, the assessment must be updated based on the ‘actual’ values at the end of construction. No specific targets are set which could be seen as a missed opportunity for driving down emissions, and the whole life assessment is not subject to the Mayor’s zero-carbon target.
However, it must surely be seen as a step in that direction. With anywhere between 30% and 70% of a typical building’s whole life emissions associated with its construction stage, the policy feels like the first step on a journey rather than the end goal.
So, overall, how does the new version of the Plan stack up for new buildings? There are certainly positive moves with respect to sustainability, now requiring all buildings to meet the zero-carbon standard.
The introduction of new requirements including ‘Be Seen’, circular economy and whole life carbon emissions assessments are also welcomed. While the Plan could have gone further, the increased requirements at the planning stage will take time for the industry to get used to. Next time around, we should expect to see more.