Section 73 application: varying a condition in practice
Section 73 lets you vary conditions on a permission you already hold, but it cannot touch the description of development and it will not buy you more time.
A section 73 application asks your local planning authority for planning permission to build the same development without complying with one or more conditions on a permission you already hold. The description of development is not up for discussion. Only the conditions are. Get it granted and you hold a second, free-standing permission alongside the original, which is why the section 106 deed and the Community Infrastructure Levy position both need checking on the day you submit.
Most changes to a minor or major housing scheme go down this route rather than through a fresh application. The limits on it are narrower than people expect, and the courts have tightened them.
What the power actually covers
Section 73 of the Town and Country Planning Act 1990 allows an authority to grant permission "for the development of land without complying with conditions subject to which a previous planning permission was granted". The same section tells the officer what to look at: the question of the conditions, and nothing beyond that. Whether the development is acceptable in principle was settled when the original permission was issued, and that is not reopened.
Two things follow from the wording.
The grant creates a new permission with its own reference number. It is not an edit to the old one. The original stays alive and implementable, so either can be built out, which matters when a lender has already taken security against the first consent.
The authority also has to reimpose the conditions it wants to carry forward. A condition left off the new decision notice does not apply to the new permission. Read the draft notice line by line before it is issued. A missing materials or landscaping condition sounds harmless until a discharge application comes back refused because there is nothing on the permission to discharge.
The limits that catch people out
A vary condition application cannot change the description of development. In Finney v Welsh Ministers [2019] EWCA Civ 1868 the Court of Appeal held that a condition cannot be varied in a way that conflicts with the operative words of the permission. The case concerned a wind turbine whose tip height was written into the description, and the attempt to raise it by condition failed. If the thing you want to change appears in the description itself, section 73 is the wrong form. That is the fundamental alteration limit in practice, and it is why descriptions on outline and full permissions should be drafted as loosely as the authority will accept.
Section 73(5) closes the route entirely once the clock has run out. Where the earlier permission carried a condition setting the time within which development had to begin, and that time has passed without a start on site, there is nothing left to vary.
Nor is this a way of buying more time. The new permission is normally conditioned so that development must begin by the date already fixed in the original grant, so a section 73 does not reset a start date that is two months away.
And the obligations do not travel on their own. A section 106 agreement tied to the earlier permission usually needs a deed of variation or a supplemental deed naming the new permission, or the authority will refuse to issue the decision. If the agreement contains staged or alternative triggers, the drafting matters more than it looks, which is covered in our note on cascade mechanisms in a section 106 agreement.
How a case officer handles the application
- Submit on the standard application form through the Planning Portal, identifying the original permission reference and each condition to be varied.
- Provide the original decision notice, the superseded drawing numbers and the replacement drawings, with a short statement explaining why the variation is sought.
- The authority publicises the application in the usual way under the Town and Country Planning (Development Management Procedure) (England) Order 2015, so neighbours can comment again.
- Statutory and internal consultees are re-consulted where the variation touches their interest, typically the lead local flood authority on a drainage condition or the highway authority on an access condition.
- Determination runs to the normal periods, eight weeks for a minor application and 13 weeks for a major one, unless an extension of time is agreed.
Where the original was Environmental Impact Assessment development, the authority has to consider whether the variation means further environmental information is needed before it can decide. That question is worth answering in the submission rather than waiting to be asked, and the thresholds are set out in our piece on environmental information under the EIA Regulations.
An illustrative variation on a 48-dwelling scheme
The following example is illustrative only.
A permission is described as "Erection of 48 dwellings with associated access, parking and landscaping". Condition 4 lists the approved drawings. The contractor wants to substitute house types on 11 plots, shift a foul pumping station nine metres to clear a drainage easement, and change the brick to a blend the supplier can actually deliver.
None of that touches the description. The unit count stays at 48, the access point does not move, and the use is unchanged. So a single section 73 application varying conditions 4, 9 and 14 does the job, with revised site layout, street elevations and a materials schedule. The authority re-consults the highway authority on the pumping station access and reimposes the remaining 22 conditions on the new permission.
Change the same facts so that the house type substitution adds two plots, and the description is wrong. That is a fresh application.
Section 73, section 96A and a fresh application
| Route | What it can change | What you end up with |
|---|---|---|
| Section 96A | Non-material amendments only, judged against the permission as a whole | The original permission, amended |
| Section 73 | Conditions, provided the description still holds | A new permission alongside the original |
| Fresh application | Anything, including the description and the unit count | A new permission determined on current policy |
Section 96A is the quicker, lower-cost instrument, and it amends the permission in place rather than creating a new one, but it cannot alter the description of development either and authorities read "non-material" strictly. A fresh application reopens the principle, which means current local plan policy, current biodiversity net gain duties and any new constraint all apply. On a scheme consented three years ago that can be an expensive reset, and it is the reason section 73 is worth protecting.
The Levelling-up and Regeneration Act 2023 inserted a further power, section 73B, for permissions that are not substantially different from the existing one. As at October 2026 you should confirm whether it has been brought into force before you build a programme around it, because the route only exists once the regulations bringing it into force are made.
Checking the position for a site
Start with the decision notice rather than the drawings. Copy the description of development into your application and ask whether the change you want would make that sentence inaccurate. If it would, stop.
Then check four things: whether the time limit for beginning development has expired, whether the section 106 needs a deed of variation, whether the Community Infrastructure Levy liability will be recalculated and credited, and whether any condition you are relying on was discharged under the original reference rather than the new one. Discharges do not automatically carry across, and that catches people out on conditions which have to be discharged before works start. Planning fees for applications to vary conditions are set nationally and indexed annually from 1 April, so check the current schedule before you budget.
A section 73 submission still needs a short, policy-aware covering document, and a Planning Statement that explains the variation against the conditions actually under consideration is usually enough. Enter your postcode on PlanScope to see which supporting documents your site is likely to need.
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.
Frequently asked questions
Does a section 73 application create a new planning permission?
Yes. A grant under section 73 produces a new, free-standing permission with its own reference number, sitting alongside the original rather than replacing it. Either permission can be implemented. The practical consequence is that the section 106 agreement usually needs a deed of variation naming the new permission, and the authority must reimpose every condition it wants to keep.
Can section 73 be used to extend the time limit on a permission?
No. The new permission is normally conditioned so development must begin by the date fixed in the original grant, and section 73(5) blocks the route entirely once that start date has passed without a start on site. If the clock has run out your options are a fresh application or, where the works already started lawfully, evidence that implementation occurred in time.
What is the fundamental alteration limit?
It is the rule that a condition cannot be varied in a way that conflicts with the description of development on the permission. Finney v Welsh Ministers in 2019 settled the point in the Court of Appeal. If the figure or feature you want to change is written into the description, such as a unit count or a building height, section 73 cannot deliver it.
Section 73 or section 96A: which should I use?
Use section 96A where the change is genuinely non-material and you want the original permission amended in place, which is quicker and costs less. Use section 73 where a condition needs replacing and the description still describes the scheme accurately. Neither can change the description of development, so a change to unit numbers or use needs a fresh application.
Will my CIL liability change on a section 73 permission?
It can. A section 73 permission is a separate chargeable development, and the Community Infrastructure Levy Regulations 2010 set out how liability is recalculated and credit given for the earlier permission where the floorspace is unchanged. Ask the charging authority to confirm the position in writing before the new permission is implemented, because the notice served on the charging authority before works begin has to match the permission being built.
Do discharged conditions carry over to the new permission?
Not automatically. Approvals obtained under the original reference relate to the original permission, so conditions discharged before works started on the original permission, where reimposed on the section 73 permission, may need discharging again under the new reference. Ask the case officer to confirm in the decision notice or by email which discharges the authority treats as satisfied, and keep that confirmation with the title documents.
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.