- What it is
- Permitted development that requires the Council to approve specified matters first
- Grounds of assessment
- Closed list, set by the GPDO. Nothing else is relevant
- Deadline
- Typically 56 days. Miss it and the development may proceed
- Council fee
- £249 for larger home extensions, £260 per dwelling for conversions, from 1 April 2026
- Our fee
- Fixed, quoted on the class
Why it is usually the better route
On a full application the Council can refuse for any planning reason it can evidence. On prior approval it cannot. The General Permitted Development Order states exactly which matters the Council may consider, and a refusal on anything outside that list is a refusal that falls over on appeal.
The second advantage is the clock. Most prior approval routes give the Council 56 days from a valid submission. If the Council fails to determine within the period, the development can proceed in accordance with what was submitted. That deadline is real, and it is why the submission has to be right first time: an invalid submission does not start the clock.
The classes we use most
Larger home extensions (Class A, prior approval under A.4)
Single storey rear extensions beyond the normal permitted development limits: up to eight metres on a detached house, six metres otherwise, subject to height limits and not in a conservation area or other protected land. The Council notifies adjoining owners, and the only matter it may consider is the impact on the amenity of adjoining premises. Not design, not character, not parking.
Commercial to residential (Class MA)
Class E premises to dwellinghouses, subject to the building having been in Class E use for two years and vacant for three months. Prior approval covers flooding, contamination, transport, noise from commercial premises, the provision of natural light to all habitable rooms, and in some cases the impact of losing the ground floor use in a conservation area. Natural light is the ground that catches most schemes, and it is an evidenced daylight assessment, not an assertion.
Agricultural to residential (Class Q)
Agricultural buildings to dwellings. The most contested class in the Order. Prior approval covers transport and highways, noise, contamination, flooding, whether the location makes residential use impractical or undesirable, design and external appearance, and the provision of adequate natural light. The recurring battleground is whether the building is capable of conversion without works that go beyond what the class permits, which is a structural engineer's report question rather than an architect's.
Others
Agricultural buildings to commercial or educational use, demolition and rebuild classes, upward extensions, telecoms, temporary uses and changes within Class E. If you are not sure whether a class covers what you want, that is a question worth asking before you commission drawings.
Prior approval submissions are refused or invalidated on paperwork far more often than on merits. The exact plans, the exact statements, the correct notification of adjoining owners, the correct declaration. Get one element wrong and either the clock never started or the Council has a clean procedural refusal. This is precisely the kind of application where doing it yourself costs more than the fee.
What we do
- Confirm the class applies, and that no condition or Article 4 direction removes it
- Check the qualifying conditions: dates of use, vacancy, size, height, protected land
- Prepare the submission exactly to the requirements of the class
- Commission or co-ordinate the daylight, structural, noise or transport evidence the class requires
- Handle adjoining owner notification correctly
- Track the 56 day deadline and hold the Council to it
- Appeal a refusal on grounds outside the permitted list, where those are the reasons given