GPDO Changes in 2026: What's New for Homeowners

The government's consultation on reforms to the General Permitted Development Order (GPDO) included several proposals that would directly affect homeowners. The key proposals are:

Larger extensions without planning permission

The proposal: Increase the maximum depth of single-storey rear extensions under PD from 4m (detached) / 3m (semi/terraced) to potentially 5m or 6m for all house types without needing prior approval.

What it would mean: Homeowners could build deeper extensions without any council involvement — not even the neighbour notification process that currently applies to larger home extensions under prior approval.

Current status: Under consultation. Not yet enacted.

Changes to the 50% curtilage rule

The proposal: Reform or remove the rule that says extensions, outbuildings, and other additions cannot cover more than 50% of the total curtilage (land around the original house).

What it would mean: Homeowners with smaller gardens could build larger extensions and outbuildings. Currently, the 50% rule is one of the most common reasons homeowners on smaller plots cannot use PD rights.

Current status: Under consultation. Not yet enacted.

Expanded loft conversion rights

The proposal: Increase or remove the volume limits for loft conversions under PD (currently 50m³ for detached/semi, 40m³ for terraced). The consultation also explored whether front dormers could be allowed under PD in certain circumstances.

What it would mean: Homeowners could build larger dormers and potentially add front dormers without planning permission.

Current status: Under consultation. Not yet enacted.

Upward extensions (additional storeys)

The proposal: Simplify the prior approval process for adding additional storeys under Class AA and potentially extend eligibility to houses built before 1948 (currently excluded).

What it would mean: A much larger number of houses would be eligible for upward extensions, including many Victorian and Edwardian properties.

Current status: Under consultation. Not yet enacted.

As of March 2026, no confirmed changes to the GPDO have been enacted from the consultation. The existing rules remain in force.

The current PD rules that apply are:

• Single-storey rear extensions: 4m (detached), 3m (semi/terraced) under standard PD; 8m / 6m under prior approval
• Two-storey rear extensions: 3m maximum depth, 7m from rear boundary
• Loft conversions: 50m³ (detached/semi), 40m³ (terraced)
• 50% curtilage rule still applies
• All designated land restrictions still apply

We will update this page when any changes are confirmed.

If you are planning a project now: Use the current rules. Do not design your project based on proposed changes that have not been enacted. If the rules change after you have started, you may be able to benefit — but planning on the basis of unconfirmed changes is risky.

If you are in the early stages: It may be worth following the consultation outcome before committing to a design, particularly if:

• Your extension would be slightly beyond current PD limits and the proposed changes would bring it within PD
• Your property is close to the 50% curtilage limit
• Your loft conversion is close to the volume limit

In all cases: Check your current PD rights and work with the rules as they stand.

We update this page whenever new information is released. You can also:

• Check the gov.uk planning pages for official announcements
• Sign up to our email newsletter for plain-English updates when rules change
• Follow BILTD on social media for immediate updates