Check whether permission is actually missing
First establish what was built, when it was built and what permissions or national permitted development rights covered it. If the work is already lawful, the appropriate route may be a certificate of lawfulness rather than a request for a new planning permission. A certificate is determined on the legal evidence, not the planning merits of retaining the development. [4][5]
If an existing permission was not followed, have the extent of the departure assessed. Do not describe a materially different extension as an approved scheme merely because a decision notice exists somewhere in the property file. The government’s enforcement guidance includes non-compliance with permission conditions within the concept of a planning breach. [2]
How the council considers the application
The application needs to show the development that actually exists, including the relevant dimensions, elevations and relationship to the site. The planning authority may invite an application where this is an appropriate way to address unauthorised development, but that invitation is not an undertaking to approve it. [2][1]
The NPPF published on 17 August 2026 contains an important policy at DM8. When deciding a retrospective application or an enforcement appeal, the decision-maker should give substantial weight to intentional unauthorised development where the available evidence leads to that conclusion. It is therefore inaccurate to promise that deliberately building first will have no bearing on the assessment. [6]
That does not turn every missing document into proof of deliberate wrongdoing. Provide an accurate chronology and the relevant evidence; leave the legal and planning assessment of the particular circumstances to the advisers and decision-maker. DM8 expressly links the conclusion to evidence. [6]
Prepare the retention case and any changes
Ask the designer or planning adviser to separate the scheme you wish to retain from any alterations proposed to make it acceptable. A sensible submission plan identifies the existing breach, the applicable route, the supporting information and any necessary remedial design. Pre-application discussion can help identify planning issues and information requirements, but is not binding approval. [7]
If permission is refused, enforcement may require the unauthorised development to be removed or the breach remedied. Where an enforcement notice has already been issued, application and appeal routes interact and restrictions can apply. Seek advice promptly rather than assuming a fresh application pauses a notice or preserves every appeal option. [1][2]
Fees and completion of the process
Obtain the fee for the exact application route and submission date. The government has announced revised national planning fees intended for 8 December 2026, subject to Parliamentary approval. Use the made instrument and operative schedule rather than treating a proposed replacement amount as current. [8][9][10]
New national planning-committee delegation rules are confirmed to take effect on 31 October 2026. They concern how applications are determined, not an automatic right to retrospective permission. [8]
After any approval, read the conditions and deal separately with outstanding building control. Retaining the structure in planning terms does not establish its technical compliance. This is a legal planning procedure, so obtain case-specific advice where enforcement is involved. [3][2]