How to Meet Part L Compliance for New Buildings in the UK

Written By Louise Dunckley

Part L of the Building Regulations sets the standard for energy performance in new and existing buildings across the UK.

For developers, architects, and project teams, meeting Part L requirements is a critical step in achieving planning approval and building control sign-off.

This guide explains what Part L requires, how compliance is measured, and the most effective ways to meet the standards.

What is Part L?

Part L focuses on improving the energy efficiency of buildings by limiting carbon emissions and reducing energy demand.

It applies to:

  • New residential developments

  • Commercial buildings

  • Extensions and major refurbishments

The current regulations place greater emphasis on:

  • Lower carbon emissions

  • Improved building fabric performance

  • Integration of low-carbon technologies

How is compliance measured?

Compliance is demonstrated through energy modelling:

  • SAP calculations for residential developments

  • SBEM calculations for commercial buildings

These models assess:

  • Energy use

  • Carbon emissions

  • Overall building performance

Your design must meet or outperform the target values set by regulations.

Key ways to meet Part L requirements

1. Improve building fabric

High levels of insulation, airtightness, and efficient glazing reduce energy demand from the outset.

2. Use efficient systems

Heating, cooling, and lighting systems must be designed for maximum efficiency.

3. Integrate renewable energy

Solar PV, heat pumps, and other technologies help reduce carbon emissions and improve compliance margins.

4. Optimise design early

Energy performance should be considered from the concept stage, not added later.

Common challenges

  • Designs that meet minimum standards but fail local planning policy

  • Late-stage changes increasing costs

  • Misalignment between planning and building regulation requirements

How Helix Energy can help

Helix Energy supports projects through:

  • SAP and SBEM calculations

  • Energy strategy development

  • Integration of renewable technologies

  • Ongoing compliance support

Meeting Part L compliance requires a combination of good design, accurate modelling, and early planning.

Getting this right from the start can reduce costs and streamline the approval process.

If you need support meeting Part L requirements, Helix Energy can guide your project from design through to compliance - contact us for further assistance.

Louise Dunckley
Next

Do I Need an Energy Statement for Planning Permission in the UK?