Do Building Regulations Apply to Your External Wall Project?

When you undertake work on your external walls, you often need to gain Building Regulations approval. This process ensures that your project meets essential standards for safety, energy efficiency, and structural integrity.

When Your Project Likely Needs Approval

Building Regulations typically come into play for the following types of work:

• Major Surface Alterations: If you intend to re-render, re-clad, re-plaster, or re-line the inside of an external wall, and this work covers 25% or more of that wall's surface.

• Significant Rebuilding: Should you rebuild 25% or more of the outer layer (external leaf) of any wall.

For both of the scenarios described above, you will generally be required to enhance the wall's thermal insulation to comply with today's energy efficiency requirements.

• Adding Cavity Wall Insulation: If you are planning to fill a cavity wall with insulation, Building Regulations apply. These regulations ensure that the insulation material you choose is suitable for the job. Please note, for certain types of foam insulation, you also need to assess the risk of formaldehyde gas emissions.

• Upgrading Thermal Elements: When you renovate a 'thermal element' of a wall, you'll probably need to improve its thermal insulation at the same time. A thermal element is any part of your wall that helps keep heat in or out – this could involve adding insulation, replacing a large section of the wall, or altering its interior or exterior finish. This upgrade is usually required if it's economically viable, and it must meet the specific standards detailed in the Approved Documents (official guidance on how to comply with Building Regulations).

Simply redecorating the surface of an existing wall, such as repainting, typically does not require Building Regulations approval.