Prior approval against permitted development without it
Schedule 2 to the GPDO 2015 splits permitted development into rights you can simply exercise and rights suspended until prior approval. The difference governs certainty, fees and conditions.
Some permitted development rights can be exercised the day you decide to build. Others cannot be touched until the local planning authority has had a defined look at a defined list of matters and either approved them or run out of time. That is the whole of the prior approval vs permitted development distinction, and it sits in the drafting of Schedule 2 to the Town and Country Planning (General Permitted Development) (England) Order 2015.
The practical consequence for anyone converting buildings is this. An automatic right gives you certainty on day one and no paper trail. A prior approval right gives you a determination to show a lender or a buyer, a fee to pay, a wait of several weeks, and conditions you did not write.
Rights that need no application at all
Most householder rights in Part 1 of Schedule 2 operate without any application. A single-storey rear extension within the depth, height and materials limits in Class A, a roof alteration within Class C, an outbuilding within Class E: build them within the limitations and conditions and no application is required.
The same structure appears elsewhere. Part 2 gates and fences, Part 6 agricultural building rights below the size trigger, Part 14 Class A domestic solar within the stated limits, and Part 14 Class G air source heat pumps within the MCS and siting conditions all run automatically. Part 3 contains a small number of change of use rights that also need no application, for example movements that take a building from one use into another where the Order grants the change outright.
The catch is that an automatic right is only automatic if every limitation and condition is satisfied. Get one wrong, such as building in the side extension zone on an Article 2(3) land designation, and there was never a right at all. There is no partial compliance.
Rights conditional on prior approval
Where the Order says development is permitted "subject to prior approval", the right exists but it is suspended until the procedure is completed. The main ones a landlord or investor meets are:
- Part 1 Class A larger home extensions, where paragraph A.4 operates a neighbour consultation scheme for single-storey rear extensions beyond the ordinary depth limits.
- Part 3 Class MA, commercial, business and service use to dwellinghouses.
- Part 3 Class Q, agricultural buildings to dwellinghouses.
- Part 20 Class AA, upward extension of certain blocks of flats and other buildings to create new homes.
- Part 16 Class A, electronic communications apparatus, for defined categories.
- Part 6 agricultural buildings and excavations above the size trigger, through the prior notification route.
Each class has its own list of what the authority may consider, and that list is the boundary of the assessment. This is the point most often misunderstood. A prior approval is not a planning application with a narrower form. It is a different beast with a closed set of considerations.
What the authority may consider in each case
Under Class MA the authority may consider transport impacts, particularly on highway safety, contamination risk on the site, flooding risk, noise impacts from existing commercial premises on the intended occupiers, and the provision of adequate natural light in all habitable rooms. Where the building is in a conservation area and the change relates to ground floor commercial use, the impact of that loss can also be considered. Design, affordable housing, loss of employment floorspace and amenity in the general sense are outside the list.
Under Class Q the considerations include transport and highways, noise, contamination, flooding, whether the location makes residential use impractical or undesirable, the design or external appearance of the building, and the provision of adequate natural light. Under Class AA the list is longer and includes the external appearance, air traffic and defence safeguarding, and the impact on amenity of the existing building and neighbours, including overlooking, privacy and loss of light.
That difference changes what you submit. A Class MA application usually needs a contamination screening note, a flood risk position, a noise assessment where a commercial neighbour is active, and a daylight study for the habitable rooms. A land contamination assessment at Phase 1 desk study level is often enough to discharge the contamination limb, with intrusive work reserved for a condition. Where a takeaway, workshop or late-opening unit adjoins, a Noise Impact Assessment addressing the effect on the proposed flats is the document that answers the statutory question, and a daylight and sunlight assessment covering every habitable room answers the natural light limb.
Deemed approval where the authority fails to decide
Paragraph W of Part 3 sets the procedure for most Part 3 prior approvals and contains the provision investors care most about. Where the authority does not notify the applicant of its determination within 56 days of a valid application, the development may proceed as if prior approval had been given. The 56 days runs from the day immediately after the valid application is received, and the application must have been valid, with the right information and the correct fee, for the clock to have started.
The equivalent mechanism in Part 1 paragraph A.4 is different in shape. For a larger home extension the authority has 42 days from receipt, and if it does not notify the applicant within that period the development may proceed, provided the other conditions of the Class are met.
Deemed approval is a real right and it is also a trap. A development that proceeds on deemed approval carries no written conditions and no decision notice, which lenders and buyers dislike. And a deemed approval obtained on an invalid application is worth nothing. Where the authority has gone quiet near the end of the period, write to confirm the validation date and the expiry date rather than relying on your own count. Most prior approvals are issued under delegated powers rather than going to members, and the delegation arrangements are explained in committee determination or delegated decision.
Fees and determination periods
Prior approval applications carry fees set in the Town and Country Planning (Fees for Applications, Deemed Applications, Requests and Site Visits) (England) Regulations 2012 as amended. The figures are uplifted periodically and have been subject to annual indexation, so check the current schedule on the Planning Portal before you submit rather than relying on a figure from a previous application. An application made with the wrong fee is invalid, and an invalid application does not start the 56-day or 42-day clock.
| Route | Application required | Statutory period | Deemed approval available |
|---|---|---|---|
| Automatic permitted development | None | Not applicable | Not applicable |
| Part 1 Class A larger home extension | Prior approval, neighbour consultation | 42 days | Yes, on compliance |
| Part 3 Class MA or Class Q | Prior approval under paragraph W | 56 days | Yes, on validity |
| Part 20 Class AA | Prior approval | 8 weeks under the relevant provision | Verify the current wording |
| Full planning permission | Yes | 8 weeks minor, 13 weeks major | No |
Conditions attached to prior approvals
An authority granting prior approval may impose conditions, and under paragraph W it may require the development to be carried out in accordance with the approved details. Class MA brings its own built-in conditions, including a restriction that the development must be completed within three years of the prior approval date.
Read the conditions for anything that affects the investment case: a restriction on occupancy, a requirement for intrusive site investigation and remediation before occupation, an obligation to install acoustic glazing and mechanical ventilation, or a requirement for cycle and refuse storage. Those are the conditions that turn a viable conversion into a marginal one, and they arrive after the appraisal is done.
Confirming the position with a certificate
Where the right is automatic and the stakes are high, the only formal way to put the question beyond argument is a lawful development certificate. Section 192 of the Town and Country Planning Act 1990 covers a proposed use or operation, and section 191 covers an existing one. A certificate under section 192 confirming that works would be lawful costs a fee, takes eight weeks, and gives a document a solicitor can rely on.
For a prior approval route, the determination itself does that job. Keep the decision notice, the approved plans and the validation correspondence together, because in five years the only person who will be able to reconstruct what happened is whoever kept the file.
This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. For a scheme where several documents are needed at once, the full list of report types shows what each one covers, and you can enter your postcode on PlanScope to see which reports a site is likely to need.
Frequently asked questions
What is the difference between prior approval and planning permission?
A prior approval application tests only the matters the relevant class of the GPDO lists, such as transport, contamination, flooding, noise and natural light under Class MA. A planning application tests the proposal against the whole development plan and all material considerations. The right already exists in a prior approval case, which is why the assessment is closed rather than open.
How does the 56 day deemed approval work?
Paragraph W of Part 3 of the GPDO allows the development to proceed where the authority has not notified the applicant of its determination within 56 days of a valid application. Validity matters, because an application with missing information or the wrong fee never started the clock. Confirm the validation date with the authority in writing rather than counting yourself.
Can an authority impose conditions on a prior approval?
Yes. Paragraph W allows the authority to require the development to be carried out in accordance with approved details, and conditions are common on contamination remediation, acoustic glazing and ventilation, cycle and refuse storage and occupancy. Class MA also carries a built-in condition requiring completion within three years of the prior approval date.
Do larger home extensions need prior approval?
Single-storey rear extensions beyond the ordinary depth limits in Part 1 Class A are permitted subject to the neighbour consultation scheme in paragraph A.4. The authority has 42 days from receipt to notify a decision, and the works may proceed if it does not, provided every other limitation and condition of the Class is satisfied.
How do I prove permitted development rights to a lender?
A lawful development certificate is the only formal confirmation. Section 192 of the Town and Country Planning Act 1990 covers proposed works or uses and section 191 covers existing ones. Both carry a fee and take around eight weeks. Where you used a prior approval route, keep the decision notice, approved plans and validation correspondence together as the record.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.