The South West Devon Joint Local Plan (JLP) – specifically Policy DEV32 – is a requirement for development proposals to actively reduce carbon emissions across the full lifecycle of the building, not just through operational performance.

For replacement dwellings, this introduces a new layer of rigour in the planning process. Design teams must now demonstrate a robust, evidence-led approach to reducing whole life carbon (WLC) from the initial design stages of a project.

A Summary of the New Planning Policy

Policy DEV32 mandates that new developments must:

• Minimise carbon emissions throughout the life of the building, including embodied carbon and operational, maintenance, and end-of-life impact.
• Incorporate passive design and low-carbon technologies.
• Demonstrates a clear understanding of the carbon implications of material choices and construction methods.

DEV32 prioritises retention and retrofit over rebuild, unless it can be clearly justified. This encourages the upgrading and reuse of existing buildings – and if this is not feasible, then the replacement building must be demonstrated as the most carbon efficient solution.

This aligns with sustainability objectives of reducing waste from demolition, preserving embodied carbon, and minimising the environmental impact of new construction.

If the preferred option is to replace the existing dwelling, the new building must be designed to deliver the most sustainable solution possible. This typically means:

• High levels of energy efficiency, such as to Passivhaus standards
• Use of sustainable building materials
• Low or zero carbon impact
• Adaptability and resilience to climate change.

How to Address the Requirements

1. Whole life carbon assessments

As part of the design for planning process, developers should evaluate whether demolition and rebuild can genuinely deliver a lower carbon outcome compared to deep retrofit. This would provide clear justification to support planning applications where new build is proposed.

• Undertaking RICS-compliant whole life carbon assessments, aligned with LETI and GLA benchmarks and using a centralised modelling process, provides clear insight into:
  
• Embodied carbon from both materials and construction
• Operational carbon from energy use
• Lifecycle impact scenarios, including refurbishment cycles and end-of-life deconstruction.
   
   

2.     Optimise materials and building engineering systems

Specialist engineers such as Mesh who understand the DEV32 policy should work alongside the design team and the client to inform the material selection process and achieve the optimum balance between performance, durability, and embodied carbon.

By applying a combination of building performance and M&E engineering, clients can ensure that the performance of a building meets the net zero targets – cost efficiently and without overengineering.
 
 

3.     Informed support for the planning and design process

If there is clear and compelling evidence in a planning submission to demonstrate that the client’s proposals go beyond minimum compliance and actively engage with the intent and spirit of DEV32, those applications will have the best chance of success and without the need for re-submissions or amendments.

In the areas governed by DEV32, lack of evidence of justification will often delay or even derail planning applications, particularly for replacement dwellings that may be perceived as being unjustifiable.

Clients, planning consultants and architects can mitigate risk by demonstrating technical rigour and policy alignment in a way that resonates with the planning authorities and the local plan.

Mesh is launching a new CPD programme to help architects and developers better understand DEV32 and how to integrate sustainable design best practice into a project from the earliest stage.

This CPD will cover DEV32 policy stipulations, from material selection and calculating embodied carbon to avoiding overheating and integrating low carbon energy solutions. Send us an email to register your interest,      cpd@mesh-energy.com.