Conditions on permitted development you can still breach

Permitted development rights are not permission to build whatever you like within the size limits. Each class in Schedule 2 to the GPDO 2015 carries conditions, and permitted development conditions breach the right the moment they are not met. The extension stops being permitted development and becomes unauthorised development, retrospectively, from the day it was built.

That distinction catches self-builders because the conditions are short, dull and easy to skip. Three of them account for most enforcement complaints: materials, obscure glazing, and the requirement to remove equipment when it is no longer needed.

Conditions built into the Order itself

Every class in Part 1 is written in three parts. What is permitted. What is not permitted, which is the list of size and siting limits. And the conditions, which apply to development that has passed the first two tests.

The structure matters because the consequences differ. Exceeding a limit means the works were never permitted development at all. Breaching a condition means the works were permitted development but the right has not been complied with, and the development is unauthorised in the same way.

Either way the council can take enforcement action, and either way the works are not lawful until they are regularised. A buyer's solicitor will not distinguish between the two.

The conditions are not discretionary and they are not negotiable with the case officer, because there is no application and therefore no officer. Nobody checks a permitted development scheme unless somebody complains, which is why breaches are often discovered years later at the point of sale.

Materials of similar appearance and how it is judged

The most common condition requires that the materials used in the exterior work are of a similar appearance to those used in the exterior of the existing house. It applies to extensions under Class A and to roof enlargements under Class B, with a carve-out for conservatories.

Similar appearance is a visual test, not a specification match. A modern facing brick that reads as the same colour and texture from the street usually passes. A different brick module, a smooth engineering brick against a soft red stock, or render against exposed brickwork usually does not.

Three points that come up repeatedly. Roof tiles are part of the exterior, so a concrete interlocking tile on an extension to a house with clay plain tiles is a breach even where the brickwork matches. Windows and doors are part of the exterior appearance too, though officers apply a lighter touch there. And weathering counts against you: a new brick matched to a 90 year old wall in its clean state will not look similar once it is up.

If the match is arguable, photograph the existing wall and the sample panel together, in daylight, before the bricklayer starts. That photograph is the evidence in any later dispute and it costs nothing.

Obscure glazing and non-opening lights

The second condition applies to windows in a wall or roof slope forming a side elevation of the house. Any such window at first floor level or above must be obscure-glazed, and it must be non-opening unless the opening part is more than 1.7 metres above the floor of the room in which it is installed.

Four things go wrong with it.

Obscure glazing is treated as a finish rather than a permanent requirement, and the glass is later replaced with clear when a bathroom becomes a bedroom. The condition continues to apply.

The 1.7 metre measurement is taken from the floor of the room, not from the outside ground level, and on a room with a raised floor build-up the dimension is measured after the finished floor is laid.

A rooflight in a side-facing roof slope is caught by the same condition, which surprises people who assume it applies only to vertical windows.

And the level of obscurity is not specified in the Order, so a lightly textured glass may satisfy the letter while a neighbour reasonably complains. Where privacy is the point, specify a higher obscurity level than the minimum you think you can argue for.

Removal conditions on equipment

Several classes attach a condition requiring equipment to be removed as soon as reasonably practicable when it is no longer needed, and requiring it to be sited to minimise its effect on the external appearance of the building.

Antennas and satellite dishes carry this. So does electric vehicle charging equipment installed under permitted development, and various forms of temporary equipment.

The removal condition is rarely enforced on its own, and it becomes relevant when something else brings the council to the site. A redundant dish on a chimney, an abandoned flue, or a charging upstand serving a parking space that no longer exists all become live issues once an officer is standing in the street with a complaint form.

The siting limb has more practical force. Equipment placed on a prominent elevation when a rear position was available breaches the condition even though the equipment itself is permitted.

What happens when a condition is breached

The council's options run from a letter to a formal notice, and most cases stop at the first stage.

An officer usually writes asking for the works to be brought into compliance, which for a materials breach may mean rendering, painting or replacing a section, and for a glazing breach means fitting obscure glass and fixing the opening light shut. Doing that promptly ends the matter.

Where it is not resolved, an enforcement notice can be served requiring specified steps within a compliance period, with a right of appeal to the Planning Inspectorate. Failure to comply with an effective notice is an offence.

Time limits matter. Enforcement against operational development has historically been subject to a four year limit, with ten years for most changes of use and breaches of condition. The Levelling-up and Regeneration Act 2023 moves those limits to ten years in England, and the date that change took effect should be verified against the current legislation before relying on either figure. Do not assume a breach has become immune because a few years have passed.

Immunity, where it applies, does not make the development lawful automatically. It makes it immune from enforcement, and converting that into a lawful position needs a certificate.

Regularising works that fell outside the right

Two routes exist and they answer different questions.

A Lawful Development Certificate for existing development under section 191 of the Town and Country Planning Act 1990 asks the council to confirm that what has been built is lawful, either because it complied with the right or because it is now immune. It is a question of fact and law, and it needs evidence: dated photographs, invoices, delivery notes, a statutory declaration where necessary. The council cannot refuse it on planning merits.

A retrospective planning application under section 73A asks the council to grant permission for what has been built. It is judged on planning merits, it attracts publicity and neighbour consultation, and it can be refused.

Choose the certificate route where the facts support it, because merits do not come into it. Choose the application where the works clearly breached a condition and there is no immunity argument. A short Planning Statement setting out the planning case, and a Design and Access Statement where the appearance is the issue, are the documents that carry a retrospective application.

Before either, read the original permission for the house if it was built in the last few decades. Conditions on new housing estates frequently withdraw Part 1 rights entirely, and an extension built in reliance on rights that were removed in 1998 was never permitted development at all.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. Browse the report index to see which documents a retrospective application needs.