The description of development: why the wording binds you
Conditions can be varied and plans amended. The description of development cannot, which is why a unit count in the wrong place fixes a scheme for its whole life.
The description of development in planning terms is the sentence on the application form that becomes the operative part of the permission, and it constrains what you can build far more tightly than most architects expect. Conditions can be varied. Plans can be amended. The description is close to fixed once permission is granted, and a description that says "erection of 25 dwellings" is a permission for 25 dwellings, not for 24 and not for 26.
What the description does on the decision notice
A planning permission grants consent for the development described in the application, subject to conditions and in accordance with the approved plans. The description is the definition of the thing permitted. Everything else qualifies it.
That has three consequences. The description sets the limits of what is lawful, so building something outside it is unauthorised development rather than a breach of condition. It determines what can later be varied, because the tools for changing a permission work on conditions and details rather than on the operative grant. And it is the text a purchaser's solicitor, a funder and an enforcement officer will read first.
Officers draft descriptions too. Where the description you submit is imprecise, the case officer will often rewrite it before validation, and the rewritten version is the one that binds you. Read what comes back.
How the wording limits what you can build
The practical test is simple. Take the description, imagine the scheme built slightly differently, and ask whether the built thing still answers the words.
A description reading "erection of a two storey side extension" does not authorise a single storey one, and a scheme that shrinks during value engineering can end up outside its own permission. "Change of use from offices to eight flats" does not authorise seven. "Erection of a building comprising 1,200 m² of floorspace" caps the floorspace even where no condition mentions it.
Numbers are the sharpest edge. Once a unit count or a floorspace figure sits in the description, it cannot be varied by an application to vary conditions, because a variation cannot conflict with the operative part of the permission. The Court of Appeal settled that point in Finney v Welsh Ministers, and it changed how careful practitioners draft. If the number might move, keep it out of the description and control it by condition instead, or express it as a maximum.
Demolition is another. Where the description says "demolition of the existing building and erection of...", the demolition forms part of the permitted development, and retaining a facade you later decide to keep may take you outside the consent.
Changing the description, before and after
Before determination, the description can usually be amended by agreement with the case officer. Where the change alters the substance of what neighbours were told, expect re-advertisement and a further consultation period, which adds at least three weeks. Where it corrects an error or adds precision, officers normally deal with it by email and amend the register entry.
After determination the position hardens. An application under section 73 of the Town and Country Planning Act 1990 varies or removes conditions, and cannot be used to change the description into something the original permission did not authorise. A non-material amendment under section 96A deals with minor changes, and councils differ on whether they will use it to adjust wording at all, so ask before assuming.
That leaves a fresh planning application as the honest route where the development itself has changed. It is slower and it costs a fee, and it is far better than building outside a permission and discovering the problem at sale.
One practical habit. When you receive the decision notice, check the description against the drawing set that day. Transcription errors happen, and they are easy to correct in the first week and awkward two years later.
Descriptions that create problems later
Certain patterns cause recurring difficulty.
Use class references that have since changed. Permissions granted before the 2020 amendments to the Use Classes Order refer to classes that no longer exist in the same form, and how those permissions are read has generated real argument. Where an old permission is the basis for a current use, take advice rather than assuming the modern equivalent applies.
Named occupiers. A description referring to a specific operator ties the permission to that business and complicates a later letting. Describe the use, not the tenant.
Over-specification. "Erection of a three bedroom detached dwelling with detached double garage and associated landscaping" invites an argument about whether a four bedroom layout with a single garage is the permitted development. "Erection of a detached dwelling and garage" says the same thing and leaves the detail to the plans.
Under-specification. The opposite failure produces descriptions so vague that the council adds conditions to compensate, or refuses validation. "Development of land" tells nobody anything.
Descriptions mixing operations and uses without saying so. Where a scheme involves both a change of use and building works, say both, because a permission for a change of use alone does not authorise the extension you drew.
Hours, occupancy and other parameters that belong in conditions
Some information should appear in the description because it defines the development. Some should appear only in conditions, because conditions can be varied and descriptions cannot.
| Put in the description | Control by condition |
|---|---|
| The nature of the development, such as erection, change of use or demolition | Opening hours and delivery times |
| The broad use, expressed by class or plain description | Occupancy restrictions and tenure |
| Whether the application is outline, with reserved matters listed | Number of units where flexibility is needed |
| Site address and any phasing that defines separate permissions | Materials, landscaping and drainage details |
Outline applications need particular care. State that the application is in outline, identify which matters are reserved, and where a unit range is intended, use "up to" so that a lower delivery does not create a mismatch. Describing "up to 150 dwellings" also keeps the scheme clear of thresholds that a fixed higher number would cross.
Getting the wording right first time
Draft the description last, after the drawings are final, and test it against three questions. Does it cover everything you intend to build, including demolition, access works and changes of use. Does it exclude anything you might want to change later. Would a stranger reading it, with the plans, know what was permitted.
Then keep it consistent. The same wording should appear on the application form, on the drawing titles, in the Planning Statement and in the Design and Access Statement where one is required. Inconsistency between the form and the supporting documents is a common validation query and an easy one to avoid.
And keep the description short. The best descriptions are one sentence, in the present participle, naming the operation and the use, with the detail left to the drawings and conditions. Browse the supporting documents your application needs and make sure each of them uses the same sentence.
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. Enter your postcode on PlanScope to draft the supporting documents around a description you have already settled.
Frequently asked questions
Can a section 73 application change the description of development?
No. Section 73 varies or removes conditions and cannot be used to grant something that conflicts with the operative part of the permission. The Court of Appeal confirmed the point in Finney v Welsh Ministers. Where the development itself has changed, a fresh planning application is the route rather than a variation.
Should the number of units go in the description?
Only where it is fixed. Once a unit count sits in the description it cannot be varied by an application to vary conditions. If the number might move, express it as a maximum using the words up to, or leave it out of the description and control it by condition instead.
Can the description be amended before determination?
Usually yes, by agreement with the case officer. Where the change alters the substance of what neighbours were told, expect re-advertisement and a further consultation period of at least three weeks. Corrections and added precision are normally handled by email and an amendment to the register entry.
What happens if the built scheme does not match the description?
It is unauthorised development rather than a breach of condition, which is a more serious position. A scheme that shrinks during value engineering, or that retains a building the description said would be demolished, can end up outside its own permission. Check the decision notice against the drawings on the day it arrives.
Do old use class references still work?
Permissions granted before the 2020 amendments to the Use Classes Order refer to classes that no longer exist in the same form, and how those permissions are read has generated real argument. Where an old permission is the basis for a current use, take advice rather than assuming the modern equivalent applies automatically.
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.