Prior approval or a lawful development certificate

Prior approval or a lawful development certificate is not really a choice between alternatives, because the two answer different questions. A prior approval application asks the council to approve specified matters, such as transport, contamination or noise, on development that a class of the General Permitted Development Order already permits. A certificate under section 192 of the Town and Country Planning Act 1990 asks the council to certify that a proposed use or operation would be lawful at all. On a conversion scheme you may well need both, and a landlord going to a lender usually wants the certificate.

The confusion costs money, because an investor who obtains prior approval and assumes it settles everything discovers otherwise during a sale.

What a prior approval application decides

Permitted development under Schedule 2 to the Town and Country Planning (General Permitted Development) (England) Order 2015 grants the permission. Some classes then require an application to the local planning authority for prior approval of listed matters before the development can proceed.

The list is set by the class, and the authority cannot roam outside it. For the commercial to residential route under Class MA of Part 3, the matters include transport and highways impacts, contamination risk, flooding risk, noise from commercial premises, the provision of adequate natural light in all habitable rooms, fire safety for relevant buildings, and in a conservation area the effect of losing a ground floor commercial use on the character of the area.

What the authority is not deciding is whether the proposal is a good idea in planning terms. There is no general balancing exercise, no development plan test of the usual kind and no scope to refuse because the officer would prefer something else.

What the prior approval process also does not formally determine is whether your development actually falls within the class at all. Authorities consider it in practice, and a refusal on that basis is common, but a grant of prior approval is not a conclusive ruling that the qualifying conditions were met.

What a section 192 certificate decides

A section 192 application asks whether a described use or operation, if carried out, would be lawful. The answer turns on law and fact, not on merits, and the authority has no discretion to refuse something that is lawful because it dislikes it.

Where the certificate is granted, it is conclusive for the purposes of the Act as to the lawfulness of the use or operations described in it. That word is the reason certificates matter commercially. A conveyancer reading a certificate is reading a determination, not an approval of details.

The burden of proof is on the applicant, on the balance of probability. So the description of the proposed use or development has to be precise, and the evidence has to support each factual limb of the claim.

A certificate is also useful where the question is whether permission is needed at all, for example whether a change between uses falls within the same use class, or whether works amount to development.

Where you need both for the same works

This is the practical answer for most conversion schemes.

Take an office to residential conversion under Class MA. The class carries qualifying conditions: the building must have been in the relevant commercial use for a period before the application, must have been vacant for a period immediately beforehand, and there are limits on floorspace and on buildings in certain locations. Prior approval deals with the specified matters. It does not conclusively settle whether the use history and vacancy conditions were satisfied.

So on a scheme where the use history is documented and obvious, prior approval alone is usually enough. Where the building has had a mixed or interrupted history, or where the vacancy period rests on the word of a former tenant, a section 192 certificate on the qualifying conditions gives you something conclusive.

The same logic applies to agricultural conversions under Class Q, where the argument is frequently about whether the building was in agricultural use at the relevant date and whether the works go beyond what the class allows. Two applications, two fees, two clocks, and far less risk.

Determination periods and the deemed consent trap

Prior approval classes carry prescribed periods, and many of them provide that where the authority does not notify a determination within the period, the development may proceed. The period varies by class and is commonly 56 days, so read the class text rather than assuming.

That deemed route is a trap dressed as a convenience. Three reasons.

First, you hold no document. A lender, a buyer or a future purchaser sees an absence of a decision rather than an approval, and demonstrating lawfulness then depends on your own evidence of the date the application was received and what it contained.

Second, deemed approval covers only the matters that required prior approval. It says nothing about whether the development fell within the class, and if it did not, you have built without permission.

Third, all the conditions and limitations of the class still bite. A development proceeding on deemed approval that breaches a limitation is unauthorised, and there is no approval to point at.

A section 192 application has no deemed grant. If the authority does not determine it within eight weeks, the route is an appeal for non-determination rather than an assumption of success.

Fees and what has to be submitted

Both are chargeable, and the amounts are set by the fees regulations and indexed, so check the current schedule on the day you submit.

Prior approval fees are set per class and are modest compared with a full application. A certificate under section 192 is charged by reference to what a planning application for the same development would cost, at a proportion of that figure, which on a larger conversion is not a small sum. Take both figures from the current regulations.

The submission requirements differ more than the fees. A prior approval application needs the form, the plans and the specific reports the class requires, which for Class MA can mean transport information, a Contaminated Land Assessment where the risk is identified, a flood risk assessment, a Noise Impact Assessment where commercial premises adjoin, and daylight information for every habitable room.

A section 192 application needs the form, a precise description, plans identifying the land and the works, and the evidence. It does not need technical assessments, because the question is lawfulness rather than acceptability.

The evidence each route needs

For prior approval, the evidence is technical and forward looking. Reports on the specified matters, prepared to the standard the authority expects, with the mitigation proposed.

For a certificate, the evidence is factual and usually historical, even on a proposed use. Depending on the claim, that means:

1. Leases, tenancy agreements and rent demands establishing the use and its dates.
2. Business rates records and utility accounts.
3. Company records, accounts and correspondence showing trading from the premises.
4. Dated photographs and, where relevant, historic imagery.
5. Statutory declarations from people with direct knowledge, dealing with specific dates rather than general recollection.
6. Floorspace measurements taken to a stated convention.

Statutory declarations do real work here, and a vague one does none. A declaration that says a unit was vacant from a stated month to a stated month, by someone who held the keys, is evidence. One that says the building was empty for a while is not.

Which one a lender or buyer wants

A certificate, almost every time.

Lenders' solicitors are looking for an unambiguous answer to a single question: is this lawful. A section 192 certificate provides that in terms, it is conclusive for the purposes of the Act, and it is recorded on the planning register. A prior approval notice approves specified matters and leaves the qualifying conditions as something a solicitor has to satisfy themselves about from your evidence.

For a landlord planning to refinance or sell within a few years, the additional fee and the additional eight weeks are usually the least expensive insurance available on the scheme. For an owner-occupier with no near-term transaction, prior approval alone may be proportionate.

The sequencing point is simple. Apply for the certificate first or at the same time, not after the works. A certificate for a proposed use is a different and easier application than one for an existing use you have already implemented. The equivalent decision between routes at the householder end of the market is set out in the article on householder application or full application, and the general principle that two processes can run on the same scheme is covered in the article on tree surveys and tree preservation order applications.

Work out which technical reports a prior approval route will need before you commit to it, and the report types index sets out what each one covers.

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.