Net zero policy in practice – Client interview
An interview with Emily Rubin from Cornwall Council
Cornwall Council has been implementing their net zero housing policy for new developments since June 2023. It is a success story which can benefit others across the UK. We wanted to understand the journey they have been on and what they found out along the way, so we interviewed Emily Rubin, Senior Project Lead in the Planning & Sustainable Development team at Cornwall Council. It was a fascinating and insightful conversation.
You have an exemplary net zero carbon housing policy for new developments in Cornwall. Could you summarise the key stages and milestones you have been through in the last few years?
It all started with Cornwall Council declaring a Climate Emergency in 2019. This instigated an Action Plan requiring a planning response which in turn kickstarted work on our Climate Emergency Development Plan Document (DPD). The DPD covers each area where planning can help to manage and mitigate the impacts of climate change and deliver benefits for our communities. An example being new build homes achieving net zero which also helps to address fuel poverty.
Early and ongoing collaboration has been key from the early stages through to adoption and implementation. We worked closely with the South West Net Zero Hub, Bath & North East Somerset and Etude in the development of the technical evidence, policy wording and guidance. This was achieved at pace given the pressing nature of the Climate Emergency. We held a workshop with developers to inform the net zero policy as well as the statutory consultations. Alongside this, the costings and viability appraisal were carried out to demonstrate that the majority of new homes will still be viable.
We submitted our Climate Emergency DPD to the Planning Inspectorate in November 2021 and had our examination hearings in June 2022. This was just before Bath and North East Somerset Council had their hearings so we were able to work together on justifying the setting of energy standards in planning policy. Both authorities’ plans were found sound by their respective inspectors at the beginning of 2023. Cornwall Council adopted its Climate Emergency DPD in February 2023.
Given the very large number of planning applications received by Cornwall Council, we delayed implementing our net zero policy until June 2023. This gave us time to undertake training and publish guidance and tools for applicants. This preparation meant we hit the ground running and determined around 1,300 applications for new homes in the first year: by far the most of any English planning authority. I have been incredibly impressed how quickly our case officers, validation teams and applicants have got to grips with the new requirements and established net zero as the new norm across Cornwall.
In 2024 our Climate Emergency DPD won ‘Best Plan’ and ‘Best in Region’ in the South West RTPI Awards for Planning Excellence, followed by an award for ‘Excellence in Plan Making Practice’ in the national RTPI Awards and we know that has helped raise the prominence of what planning can achieve.
It seems like many Council officers got involved, is that correct?
Absolutely: it was a true team effort. This is important in creating policy that we know can be delivered, because it requires so many skills, specialisms and viewpoints to be considered. Colleagues from our Carbon Neutral Cornwall Team provided valuable specialist advice and input at the policy writing and inquiry stages and we continue to work closely with them as we consider future planning policy and the Local Area Energy Plan.
As we worked toward our policy implementation date, we trained colleagues in Development Management and worked collaboratively with them on the guidance and protocols. We also managed to build in measures to reduce some of the technical difficulties Building Control colleagues explained applicants had already been facing at Building Regulations stage.
To provide expert advice on individual pre-application requests and live planning applications we now have a dedicated Sustainable Energy and Construction Officer. We also have our monitoring officers who manage the money received through applicants offsetting renewable energy. In short there are lots of teams who now have the policy embedded into their work but, other than for our specialist officer, it is not a significant amount of extra work.
In a nutshell, what are you requiring applicants to do?
Applications for new build homes (full or reserved matters applications) are required to submit an Energy Summary Tool and an Energy Report. These need to demonstrate that the scheme will meet our Space Heating Demand (SHD) and total Energy Use Intensity (EUI) thresholds (30kWh/m2/year and 40kWh/m2/year respectively) plus that the total energy use is matched with renewable energy on an annual basis.
The Energy Summary Tool (developed by Etude and using SAP or PHPP data) quickly and easily shows whether each new home meets our policy standards. It also helpfully allows architects to test options in the design stages. The SAP version of the tool cleverly adjusts the raw SAP data to make it accurate for the policy’s purposes so that most applicants don’t have to use PHPP modelling, thus saving them time and money.
The Energy Report is a written overview for the case officer and other interested stakeholders. The Tool and Report are supported by the raw SAP/PHPP data and accurate drawings showing the solar panels and heat pump. The Tool, Report, data and drawings are details secured by planning condition, meaning that the development must be built out and maintained to these specifications.
Full details of Cornwall Council’s planning application requirements are set out in our Validation Guide.
Your net zero carbon housing policy for new developments has been in place for over 18 months now, how is it going?
Applicants and agents adjusted to the change very quickly – helped by work that we did to prepare them for the changes in advance of launch. Because of that, the net zero policy has felt like business as usual for a while now. The vast majority of schemes have been able to fully comply and very little off-setting has been needed. This is evidence of the policy being applied correctly.
Training, guidance and advice has gone a long way to help us successfully implement the policy and we now offer a specialist Pre-application Advice Service to further support applicants achieve net zero homes. We encourage applicants to consider energy performance at the very earliest design stages to make net zero easier and keep build costs down.
We maintain a close relationship with each of the case officer and validation teams involved so if there are any unusual cases or any tweaks needed to protocols we can get those changes agreed and make sure everyone is up to date. It’s been one of those projects which has strengthened relationships and knowledge between teams, helping things run efficiently and with positivity.
Can you tell us about how you overcame any hurdles?
Our main hurdle was demonstrating that net zero homes can be secured through planning policy. A lot of evidence was provided by the project team, including Etude and ourselves, as well as our counterparts at Bath & North East Somerset to successfully challenge the 2015 Written Ministerial Statement (ostensibly limiting local plan policies to Level 4 of the Code for Sustainable Homes). We were delighted that both inspectors found that the Written Ministerial Statement had clearly been overtaken by events and that Central Lincolnshire was able to follow suit in adopting their net zero policy in April 2023. It has been disappointing that other planning authorities now face difficulties from the 2023 WMS on local energy efficiency standards, so we are supporting those waiting in the wings wherever we can.
In implementing our net zero policy we quickly identified that for some very small homes (e.g. self-contained annexes and compact holiday lodges) the policy standards are potentially too challenging with an unavoidably high energy demand per square metre. It was however important to us to apply our policy as far as we can for very small homes because they present an opportunity to reduce carbon emissions and reduce fuel bills. We’re grateful to Etude for helping us to establish a separate, practical alternative checklist for very small homes which resolves this, includes cost saving tips and follows the principles of the policy. This checklist gives certainty to our prospective applicants and has sped up decision-making for relevant cases.
Has viability been a problem?
The Planning Inspector for the Climate Emergency Development Plan Document, which hosts our net zero policy, recognised from our Viability Appraisal that the standards “will have little effect on housing delivery”. The policy wording includes a viability provision for the minority of schemes where this is an issue but this has only been raised in a tiny minority of cases with particular circumstances. Cornwall Council remains the authority with by far the most planning applications for new homes and interest remains strong.
Do you get approached by other Local Authorities?
Yes! Authorities across England and Wales reach out to us all the time. These are very positive conversations and are an opportunity for us to hear their ideas as well as to demonstrate how net zero is possible; sharing the benefit of our experience. I have noticed that authorities are increasingly interested in the finer details of implementation as they are getting to a more advanced stage, which is really promising. Our hope has always been that net zero will become standard across the country, sooner rather than later and it is clear that many authorities share this vision. It would be great to see this reflected in the new National Development Management Policies.
In summary, what advice would you give to other Local Authorities for the different stages of policy development and implementation?
It can feel a little overwhelming for authorities who are just starting out but authorities like Cornwall Council have done much of the groundwork in terms of gathering the evidence, implementation documentation and establishing Development Management protocols. As a planning authority, you will want and need to add your own flavour, reflecting typical house types, viability, climate and priorities but it is often easier to use existing examples as a starting point and to give confidence to members and local developers on how it can work.
Given that energy is a complicated subject, clear and targeted messaging and training is key at all stages, particularly in the run-up to implementation. Time and again we have found that beginning with the purpose of the policy (for us: tackling the climate emergency and fuel poverty) is the most effective and has helped to achieve buy-in.
Also think about how to reach those developers who are less used to engaging with the council – we found builders merchants were brilliant at helping with this. Internally, we supported our front-line Validation Teams with close working and their own bespoke training, as well as welcoming them at the wider Development Management sessions.
As you develop your protocols and guidance, scenario testing is key. Development Management team leaders will be able to consider the range of applications you’re likely to receive and help consider how best to approach matters like retrospective applications, the implications of designations and local development types. For example, we receive a lot of applications for self-contained residential annexes but don’t have much medium/high rise development.
As with all new planning requirements, expect a few validation delays in the early days of implementation but trust that this is temporary. We kept a close eye and this phase was short-lived as applicants adjusted to the new requirements. Our guidance documents are “live” so we are able to update these with the benefit of feedback and experience.
Specialist advice is essential to supporting planning applications as well as building knowledge amongst case officers. Consider a pre-application advice service dedicated to net zero. This will help applicants design in energy from the early stages and can also help fund the specialist post.
And finally, do you think that a net zero carbon new housing policy like this could be implemented nationwide?
Definitely! We know that new homes need to reach net zero to slow climate change and avoid the need for retrofitting. Frontrunner authorities like Cornwall have demonstrated it is possible and there is strong interest in all of the English regions as well as the devolved nations. We see that authorities up and down the country are working through the details. The collective focus must be how quickly net zero for new homes can be ubiquitous and what more future policies and Building Regulations can do to help tackle climate change.
This interview was with Chris Worboys from Etude. Email Chris at chris.worboys@etude.co.uk for further information.