Prior approval against a full planning application
In a prior approval the permission already exists and the council decides only a short list of matters. That is why it can succeed where a full application would fail, and fail on a single narrow point.
The difference between prior approval and a full planning application is not a difference of degree. In a prior approval the permission has already been granted by the General Permitted Development Order, and the council is only deciding whether it approves the specific matters the Order lists for that class. In a full application the council decides the whole thing, against the development plan. That is why a prior approval can succeed for a scheme the same council would refuse on a full application, and why it can fail on a single narrow point you were not expecting.
What prior approval actually is
Permitted development rights are granted by the Order rather than by the council. For some classes the right is unconditional. For others it is subject to a condition that the developer must first apply to the local planning authority for a determination as to whether prior approval is required for specified matters.
So the application is not an application for permission. It is an application for a determination about a short list of matters, made against a permission that already exists provided the class limits are met.
Everything follows from that. The council cannot refuse because it dislikes the design, unless design is one of the listed matters. It cannot require affordable housing. It cannot apply a policy that is not reflected in the listed matters. And equally, you cannot use the procedure at all unless the proposal fits inside the class limits, because outside them there is no permission to have approved.
The matters the council may consider
Each class has its own list. For the change of use from commercial premises to dwellings, the matters include transport and highways impacts, contamination, flooding, noise from commercial premises affecting the intended occupiers, adequate natural light in all habitable rooms, the effect of introducing homes in an area important for industry or storage, and in a conservation area the effect of losing the ground floor use.
For upward extensions the matters are different and include the structural strength of the existing building, external appearance, air traffic and defence safeguarding, and the impact on the amenity of neighbouring premises including overlooking, privacy and loss of light.
Read the list for your class before you draw anything, because the listed matters tell you exactly what evidence to commission and what to leave out. A noise report is essential under one class and irrelevant under another. Where noise is a listed matter, a noise impact assessment using the right method for the source is the document that answers it. Where contamination is listed, the question of whether a desk study is enough is the one addressed in the article on contamination phase 1 or phase 2.
Conditions built into the class apply automatically and are not matters for the council's judgement. New dwellings created under permitted development have to meet the nationally described space standard floor areas, for example, because the Order says so.
Determination periods and the deemed approval trap
For Part 3 prior approvals the procedure in paragraph W gives the authority 56 days from receipt of a valid application to notify the applicant of its determination. Other parts have their own periods and procedures, including the neighbour consultation scheme for larger householder extensions.
If the authority does not notify a determination within the period, the development may proceed in accordance with the details submitted. That is the deemed approval, and it is a genuine advantage of the route.
It is also a trap, for three reasons.
- The period runs from receipt of a valid application. If the submission was incomplete, the clock never started and the deemed approval you are relying on does not exist.
- Proceeding on a deemed approval means proceeding on the details you submitted, so those details have to be complete and buildable.
- Nothing is issued. You have no decision notice to show a purchaser, a lender or a building control body, and evidencing the position later means assembling the submission, the validation correspondence and proof of the date.
Where the deemed route matters commercially, a lawful development certificate for proposed or existing development is the way to convert an inference into a document.
Conditions and what they can cover
An authority granting prior approval may impose conditions, and those conditions have to be reasonably related to the subject matter of the prior approval. It cannot use a condition to import a policy requirement that is not among the listed matters.
Development must then be carried out in accordance with the approved details, unless the authority and the developer agree otherwise. That phrase does real work in practice, because there is no section 73 equivalent for varying a prior approval. Changing the scheme afterwards usually means a fresh prior approval application or a full application, which is a reason to get the submitted details right rather than indicative.
Some classes carry their own completion requirement. The commercial to residential class, for instance, requires the development to be completed within three years of the date of prior approval.
Obligations, the levy and biodiversity
This is where the two routes diverge most sharply on cost.
| Prior approval | Full planning application | |
|---|---|---|
| What is assessed | A closed list of matters for that class | The whole development plan |
| Design and street scene | Only where listed for the class | Always |
| Affordable housing and planning obligations | Cannot be required | Can be required by policy |
| Biodiversity gain condition | Does not apply, as permission comes from the Order | Applies unless exempt |
| Community Infrastructure Levy | Can still be chargeable, by notice of chargeable development | Chargeable where a schedule is in force |
| Fee | Flat fee, generally lower | By dwelling, area or type |
| Varying the scheme afterwards | No variation mechanism | Section 73 or section 96A |
| Appeal against refusal | Available | Available |
The levy point catches people. Development carried out under a general consent can still be chargeable, through a notice of chargeable development, so a prior approval does not automatically mean nothing is payable. Check the authority's charging schedule and the levy procedure before you assume otherwise.
The biodiversity position runs the other way and is a real advantage of the route, since the gain condition attaches to permissions granted on an application rather than to permission granted by a development order.
Where a full application is unavoidable
Four situations, and they cover most cases.
The proposal falls outside the class limits, on floorspace, height, the use the building was previously in, or the qualifying period. The site is excluded, most commonly because the building is listed or in a designated area where the class does not apply. An Article 4 direction has withdrawn the right. Or the scheme involves building operations the class does not cover, which is the usual reason a change of use under prior approval is accompanied by a separate application for the external alterations.
There is also a choice to be made where both routes are open. A full application gives you design flexibility, the ability to include an extension, and a decision notice that is easy to evidence. A prior approval gives you a narrower test, a shorter period, a lower fee and no affordable housing exposure. On a building that will produce a poor standard of accommodation, the narrower test is not necessarily the better outcome, and a scheme that only works because nobody is allowed to assess the design tends to be difficult to sell.
What happens if prior approval is refused
An appeal lies against refusal of an approval required under a development order, so the route to the Planning Inspectorate is available in the normal way. Refusal does not remove the permitted development right either, so a revised prior approval application addressing the reason for refusal is often faster than an appeal.
An illustrative example: a first floor and second floor office conversion refused prior approval on adequate natural light, because two proposed bedrooms were served only by a recessed light well. The applicant reduced the scheme from six flats to five, merged the two affected units, submitted a daylight study with the resubmission and obtained approval on the second attempt. An appeal on the original scheme would have taken longer and would probably have failed on the same point.
Keep the planning statement for a prior approval short and structured around the listed matters, one heading each. Officers determining these have a narrow task, and a document organised the way their assessment is organised gets decided faster. The report index shows which technical documents answer each matter.
This is general guidance rather than legal advice. A lawful development certificate is the only formal way to confirm that development is lawful, and you should 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.
Frequently asked questions
What is the determination period for prior approval?
For Part 3 prior approvals the procedure gives the authority 56 days from receipt of a valid application to notify its determination, and other parts have their own periods. If no determination is notified in time, the development may proceed in accordance with the details submitted. The period only runs from a valid application, so an incomplete submission never starts it.
Can the council refuse prior approval on design grounds?
Only where external appearance or design is one of the matters listed for that class. For a change of use class the matters are typically transport, contamination, flooding, noise affecting intended occupiers and natural light, so design is outside the assessment. Conditions built into the class, such as space standards, apply automatically.
Does the biodiversity gain condition apply to prior approval?
No. The gain condition attaches to planning permission granted on an application, and permitted development takes its permission from the Order itself. That is a genuine cost and programme advantage of the route. The Community Infrastructure Levy can still be chargeable, through a notice of chargeable development, so check the authority's schedule.
Can a prior approval be varied later?
There is no equivalent of a section 73 variation. Development must be carried out in accordance with the approved details unless the authority and the developer agree otherwise, so a change normally means a fresh prior approval application or a full application. Submit complete and buildable details rather than indicative ones.
Is there an appeal against refusal of prior approval?
Yes, an appeal lies against refusal of an approval required under a development order. Refusal also does not remove the permitted development right, so a revised application addressing the reason for refusal is often quicker than an appeal, particularly where the reason was a single listed matter such as natural light to one room.
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.