Open Legal Advice has been provided by Estelle Dehon KC of Cornerstone Barristers which forms part of the body evidence established in Essex to support local planning authorities deliver healthy, energy efficient, low carbon, climate resilient homes and buildings which align with local and national climate and energy targets and deliver the best outcomes for Essex communities. The advice covers the following planning matters:

   A) The ability of local planning authorities to set planning policies in their local plans that require development to achieve higher building fabric and energy efficiency standards than the minimum requirements set out in Building Regulations.

   B) The ability of local planning authorities to require higher building fabric and energy efficiency standards than Building Regulations on new development proposals coming forward prior to the adoption of local plan policy.

Both pieces of legal advice are ‘open’ and therefore can be published.  Local Planning Authorities and other interested parties are welcome to use the advice and rely on it in public fora, such as local plan examinations and public inquiries.

Key Message: The advice sets out the clear legal justification for local planning authorities to act now and to require new build development to achieve higher building fabric and energy efficiency standards than those set in current or proposed Building Regulations. The advice has been updated following the publication of the 2026 NPPF, which further amplifies and supports the justification for authorities to require that development meets higher standards.

 A: Open Legal Advice - Energy policy in plans and Building Regulations

The open advice available on the link below consolidates and updates the previous advice (see archived document list below) and establishes the legal justification for local planning authorities to set planning policies that require new development to achieve higher building fabric and energy efficiency standards than those set out in the national baseline (Building Regulations).  Policies must be justified by a robust evidence base (e.g. Essex Energy and Carbon Evidence). The advice confirms policies can be expressed using the best practice energy metrics approach (as per Policy GE1: Operational Energy and Carbon  in Homes & Buildings set out in the Operational Energy and Carbon Planning Policy Statement (October 2025) for Greater Essex .

Essex Open Legal Advice A (Consolidated and Re-updated September 2026) – Energy policy in plans and Building Regulations (Estelle Dehon KC, Cornerstone Barristers, 16th September 2026) 

    B: Open Legal Advice - Energy policy prior to plan adoption

The open advice on the link below sets out the legal justification for local planning authorities to mandate higher building fabric and energy efficiency standards for new development than current and proposed Building Regulations prior to the adoption of formal local plan policy.

It includes the consideration of the use of Supplementary Planning Documents, Design Guides, Design Codes, other non-statutory local policy statements and draft local plan policies, and the weight applied in decision-taking. The Advice examines national policy and case law including confirmation that climate change is a mandatory material consideration and local planning authorities must consider the climate impacts of their planning decisions.  

An analysis of Essex policies relevant to climate, energy efficiency and design (as at December 2024) is also included along with bespoke advice for each Essex local planning authority.

The short Addendum produced in October 2025 confirms that the approach taken in Advice B remains valid. 

 For an overview of the content of Legal Part B, please read our Briefing Note. This includes the context for why higher standards are needed, the legal foundation Local Planning Authorities have to require these standards and the key implications and actions for Essex Local Planning Authorities.

Essex Open Legal Advice Part B - Briefing Note (ECC Climate and Planning Unit, April 2025)

Essex Open Legal Advice Part B – Energy policy prior to local plan adoption (Estelle Dehon KC, Cornerstone Barristers, 31 December 2024)

Addendum to Essex Open Legal Advices (October 2025) (Estelle Dehon KC, Cornerstone Barristers, 20th October 2025)

Documents List:

1. Essex Open Legal Advice A (Consolidated and Re-updated September 2026) – Energy policy in plans and Building Regulations (Estelle Dehon KC, Cornerstone Barristers, 16th September 2026)
2. Essex Open Legal Advice B – Energy policy prior to plan adoption (Estelle Dehon KC, Cornerstone Barristers, 31 December 2024)
3. Essex Open Legal Advice Part B - Briefing Note (ECC Climate and Planning Unit, April 2025)

Archived Documents (have been superseded but the direct links retained to allow partners time to update links embedded in other documents)

The open advice (A) was first published on 28th April 2023 and updated in February 2024 to address the 13th December 2023 Written Ministerial Statement ‘Planning – Local Energy Efficiency Standards Update’ and incorporate the Salt Cross Judgement of 20^th February 2024. A second update to the advice was published in May 2025 as there were a number of developments, including a new iteration of the NPPF (Dec 2024) and new case law.   A short Addendum to the May 2025 advice was published in October 2025 to address further case law and to ensure the Advice was kept up to date.  The Addendum confirmed the May 2025 Advice remained valid and key aspects of the Advice had been reinforced. Following the publication of a revised NPPF in August 2026, the advices have been consolidated and re-updated into the current version dated 16^th September 2026.  Going forward, the September 2026 advice should be preferred to the previous iterations, but to minimise disruption the web links to the earlier iterations have been maintained in the archived documents list below. 

• Addendum to Essex Open Legal Advices (October 2025) (Estelle Dehon KC, Cornerstone Barristers, 20th October 2025)
• Essex Open Legal Advice A (Updated May 2025) – Energy policy in plans and Building Regulations (Estelle Dehon KC, Cornerstone Barristers, 6^th May 2025)
• Essex Open Legal Advice – Energy policy and Building Regulations 2024 (Estelle Dehon KC, Cornerstone Barristers, 25 February 2024)
• Essex Open Legal Advice – Energy policy and Building Regulations 2023 (Estelle Dehon KC, Cornerstone Barristers, 28^th April 2023)