UK Permitted Development (PD) Rights in a Nutshell

When Is Retrospective Permission Required?

The short answer: retrospective planning permission is required when development has been undertaken that should have had permission but did not.

To answer that, you first need to assess whether your development falls within the rules of permitted development (PD).

Permitted Development or Planning Permission?

Permitted development rights allow certain types of works and changes of use to be carried out without a full planning application, provided they meet strict criteria set out in the General Permitted Development Order (GPDO). These rights apply primarily to dwelling houses, not flats or commercial premises and are subject to both national and local constraints.

Common examples of permitted development:

• Single-storey rear extensions within specified depth/height limits

• Certain loft conversions

• Outbuildings that are ancillary and within height and placement limits

• Some porches, fences, and gates

However, PD rights do not apply in all situations. Your project might fall outside PD if:

• Your property is in a conservation area, national park, or Area of Outstanding Natural Beauty

• You live in a listed building or its curtilage

• Previous development rights have been removed by condition

• The works exceed the volume, height, or footprint thresholds

• The building is not a house (e.g. a flat or maisonette)

If your development doesn’t meet all the PD criteria, planning permission should have been obtained—and if not, a retrospective application is necessary.

A simple checklist:

• Have I exceeded PD limits for height, depth, or floor space?

• Is my home in a protected or designated area?

• Has the council removed PD rights through a planning condition or Article 4 Direction?

• Did I change the use of the building?

If the answer to any of these is yes—or if you’re unsure—the safest course is to seek professional advice or submit a lawful development certificate (LDC) application. If it turns out permission was required and not obtained, then you’ll need to pursue retrospective approval.

How will the Council find out?

This is a common concern and not always straightforward. LPAs usually do not proactively investigate developments if something is unauthorised—it typically comes to light only when:

• A neighbour complains

• You attempt to sell or remortgage the property

• You apply for further development

• A planning officer visits the site for another reason

In many cases, owners are unaware that their works needed permission at all.

What Happens If I Ignore It?

While some unauthorised development may remain unnoticed for years, there is always a risk of planning enforcement. Councils can take action under Section 172 of the Planning Act, requiring you to:

• Apply retrospectively within a set time

• Cease the use or activity

• Remove the unauthorised structure

Ignoring the issue can result in fines, legal action, and significant costs if the council pursues direct action. Retrospective applications are much safer than waiting to be caught.

Will the Council Approve It?

This is the critical question—and the answer is: not always. A retrospective planning application is considered on its planning merits, just like any other application. If the development would not have been approved beforehand, it may be refused, and you could be required to undo the work.

That said, many retrospective applications are approved, particularly where:

• The breach is minor or technical

• The development is in keeping with local character

• There is no significant neighbour harm

• There is strong justification provided

Supporting information—such as planning statements, heritage impact assessments, or landscape appraisals—can make a significant difference to the outcome. RPE has extensive experience producing robust, persuasive statements that will significantly help your case.

What Should I Do Next?

If you’re asking “Do I need retrospective planning permission?”, the chances are you’re already unsure—and that means you need clarity. The key is to act early and decisively:

1. Determine whether the works are permitted development.

2. Check for any conditions or restrictions on your property.

3. Consult RPE – Retrospective Planning Experts to review your options.

4. Submit a retrospective application or lawful development certificate as appropriate.

At Retrospective Planning Experts we specialise in helping homeowners and small developers navigate the complexities of retrospective planning. We’ll assess your situation for free, advise on your options, and—if necessary—prepare a robust application to regularise your development.

Safeguard your property and investment – Contact RPE today.