Prior approval or full planning permission

The prior approval vs planning permission question comes down to what the council is allowed to think about. Under a full application an officer weighs the proposal against the whole development plan and every material consideration. Under prior approval the permission already exists in the General Permitted Development Order, and the council may only consider the short list of matters that the relevant Class sets out. Everything else, including whether the scheme is any good, is outside their reach.

For a landlord converting commercial floorspace or adding storeys, that difference is worth real money. It is also the reason prior approval applications fail on points that have nothing to do with planning merit.

What prior approval actually is

Permitted development rights granted by the Town and Country Planning (General Permitted Development) (England) Order 2015 come in three shapes. Some are unconditional within their limits. Some require you to notify the authority. And a growing number require an application for prior approval of specified matters before the development may go ahead.

Prior approval is not a lesser form of planning permission. The permission is already granted by the Order. What the application does is ask the authority whether it wishes to approve details of the listed matters, and that is the only question in front of it. An officer who refuses because the scheme conflicts with a local plan design policy has, in most cases, stepped outside the Order.

The practical consequence for a landlord is that the assessment is narrower, faster and more predictable, at the cost of being far less forgiving about eligibility.

The closed list of matters

Each Class sets its own list. Class MA, which permits commercial, business and service floorspace in Class E to become dwellinghouses, lists matters including transport and highways impacts, contamination risk, flooding risk, noise from commercial premises, the provision of adequate natural light to all habitable rooms, and in some circumstances the impact on the local provision of services. Upward extension classes in Part 20 add matters such as external appearance, structural strength and the impact on the amenity of the existing building and neighbours.

Two points follow.

The first is that you should answer each listed matter with its own short piece of evidence rather than one document covering everything. A contamination matter is answered by a desk study in the shape of a contaminated land assessment, a flooding matter by the flood map position and, where relevant, a Flood Risk Assessment, and a noise matter by a survey of the neighbouring commercial uses.

The second is that any matter not on the list is not a reason for refusal. Affordable housing, space standards beyond the nationally described standard where it applies as a condition, and the character of the area generally are not prior approval matters under Class MA. Where an officer raises them, a polite letter citing the Class usually resolves it.

Determination periods and deemed consent

The headline is the 56 day determination period that applies to several of the residential conversion classes, running from the date the authority receives a valid application. If the authority does not notify you of its decision within that period, the development may proceed in accordance with the details submitted. Periods differ between Classes and Parts, so read the Order for the Class you are using rather than assuming 56 days.

Deemed consent through the passage of time sounds like a gift. In practice it is a trap, for one reason.

Validity is what decides most disputes

The clock only runs from a valid application. If a required document is missing, the fee is wrong or the description does not match the Class, the authority can say the application was never valid and the deemed consent never arose. That argument surfaces months later, usually when a purchaser's solicitor asks for evidence of lawful implementation.

Three habits reduce the risk. Submit everything the Order lists for that Class, in the order the Order lists it. Pay the correct fee and keep the receipt, checking the current fee schedule because fees are indexed. And ask the authority in writing to confirm the date it treats the application as valid, then diarise the expiry date from that confirmation rather than from your submission date.

Where the stakes are high, a lawful development certificate after the event gives you something a lender will accept. The route and the wording differ, and the prior approval refusal grounds explained here are worth reading alongside this.

Conditions the Order imposes on you

A prior approval does not arrive condition-free. The Order itself attaches conditions to each Class, and they bind whether or not the decision notice repeats them.

Class MA carries conditions including completion within a set period from the date of prior approval, and use only as a dwellinghouse within Class C3. Part 1 Class AA, the upward extension of a dwellinghouse, carries conditions about materials and window positions. Several classes require development to be completed within three years.

These are conditions on the permission, so breaching them is a breach of planning control in the ordinary way, enforceable by the authority. Read them before you design, because a completion deadline changes how you programme the works.

When a full application is the better route

Prior approval is the wrong tool more often than landlords expect.

There is also a hybrid position worth considering: apply for prior approval, and run the full application in parallel where the fallback argument strengthens the full case. The existence of a genuine permitted development fallback is a material consideration in the full application, and it can do more work than any amount of design argument.

What prior approval leaves unresolved

A prior approval decides the listed matters and nothing else. Building Regulations approval is separate and is where fire safety, structure, ventilation, acoustics between dwellings and accessibility are actually tested. Party wall matters under the Party Wall etc. Act 1996 are separate again, as are rights of light, restrictive covenants and any landlord's consent under a lease.

Biodiversity net gain is treated differently for development permitted by a development order, and the exemptions have been amended since the regime started, so check the current exemption regulations before assuming either position.

None of that appears on the decision notice. It is why a converted building can hold a valid prior approval and still be unlettable, and why the Planning Statement accompanying a parallel full application is often the more useful document to have on file.

This is general guidance, not legal advice. A lawful development certificate is the only formal way to confirm that works are lawful, and you should check the position with your local planning authority or a qualified professional before relying on any permitted development route.

Working out which route your building qualifies for is the first decision, not the last. Enter your postcode on PlanScope to see which reports your site needs. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.