A planning permission is not fixed.

Three routes change it. One deadline shuts the main one.

Reviewed August 2026

The short answer

Most schemes change after consent. A non-material amendment carries a small change, a section 73 varies or removes a condition, and anything bigger needs a fresh application. Section 73 closes once the permission has lapsed.

In practice · Brandon Parade

One building, seven applications

A consent is a starting position, not a finished thing. The clearest way to show that is one address.

The order of work

01Settle the useA prior approval fixed what the building could become.

02Consent the worksSeparate permissions for the fabric and the plot.

03Vary the drawingsTwo section 73 applications on one permission.

04Name the parentEach variation states the permission it changes.

An office building at 62 Brandon Parade in Leamington Spa, taken to apartments and then adjusted across four and a half years.

The job

Site: A town-centre office building, 62 Brandon Parade, Leamington Spa
Role: Architect and agent on all seven applications
Council: Warwick District Council, refs W/19/1535, W/21/0838, W/22/0203 and W/23/1103
Outcome: Apartments, consented across three different instruments

The first move settled only what the building could be. A prior approval for the change of use from offices to homes went in during March 2019, was withdrawn in May, re-made in August and given on 23 October.

What the building needed was consented separately. The old electrical substation came down and a studio apartment took its place, granted 29 June 2020. A lift serving the first and second floors followed on 21 January 2021. External alterations, including a covered staircase and changes to the existing glazing, were granted on 20 October 2021.

Then the detail moved twice, and neither change needed a new scheme. The fenestration was revised by varying condition 2 of that October permission, granted 20 May 2022. Sixteen months later the landscaping, the pedestrian access and the position of the replacement electricity unit went the same way, granted 6 October 2023.

Seven applications, three instruments, one building. Note what the last two did not do. Neither replaced the permission it varied. Each granted a further permission standing alongside it, so three consents ended up covering the same external works, and only one of them was ever going to be built.

The withdrawal at the start earns a sentence. A prior approval is decided against a fixed list of matters and the authority either gives it or does not, so there is little room to negotiate once it is in. Withdrawing and re-making a corrected application is frequently quicker than taking the refusal, and that is what happened here.

Note also that each variation named the permission it was changing, and both named the same one. They went back to the October 2021 permission rather than to each other. That is a choice rather than an accident: a variation attaches to a single parent, and the one to name is the consent that will actually be built out.

The proof

Four consents, changed after the grant.

Route corrected · granted

A house in Dorridge

A two-storey extension over a garage, consented in February 2019. The entrance screen and the rear fenestration were put to the council as a non-material amendment and refused. A section 73 varying the plans and materials conditions was granted in July 2021.

Solihull MBC refs PL/2018/02425/MINFHO and PL/2021/01246/VAR

Two amendments · granted

Treadwell Court, Shirley

A retail block on Stratford Road, consented for flexible commercial space and eighteen apartments. Two separate non-material amendments were later made to that permission, the second matching the ground floor window widths to the floor above. One was decided in nine days and the other in fourteen.

Solihull MBC refs PL/2021/01024/NONMC and PL/2023/00030/NONMC · April 2021 and January 2023

Condition removed · granted

An office on Leam Terrace

An office to residential conversion consented as a prior approval. One condition was varied to substitute a new set of drawings, and a second, requiring contamination work, was removed outright. A condition can come off a permission altogether rather than only being adjusted.

Warwick District Council ref W/20/1884 · granted February 2021

Outline consent · varied

The Laurels, Little Kimble

An outline consent for up to fourteen homes on the edge of a Buckinghamshire village. Three of its conditions needed to move: the approved plans, the vision splays at the site entrance and the drainage held over to reserved matters. All three were varied on one section 73 rather than on three.

Buckinghamshire Council ref 21/06161/VCDN · granted November 2021

Every planning application we make in our own name is a matter of public record on a council register. Fifty-one of ours changed a permission that had already been granted, across fifteen planning authorities.

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01 · The deadline

First, check the permission is still alive

The deadline on a consent takes more than the consent. Section 73, the instrument that varies or removes a condition, says in terms that it does not apply where the previous permission was subject to a time limit and that time has expired without the development having been begun. The date that ends the permission also removes the main tool for changing it.

So the first question is whether anything is left to change. The period on the notice, three years unless it says otherwise, runs to a material operation on the ground rather than to a finished building. Miss it with nothing done and there is nothing left for a variation to attach to.

The sequence is therefore: find the decision notice, read the commencement condition, work out whether the date has passed, and only then decide which instrument you need. A reader whose consent lapsed two years ago is not on this page at all. That case is a new application against whatever policy applies now.

One narrow exception arrived on 18 February 2026. Where the validity of a permission is challenged in court, its implementation period is now extended by a year once the court gives permission for the proceedings, by a further year if permission to appeal to the Court of Appeal is given, and by two more if permission to appeal to the Supreme Court is given. Outline permissions and listed building consents get equivalent treatment. It stretches a live permission caught up in litigation. It revives nothing that has already gone.

Outline consents run to two dates rather than one, which catches people out in the same way. Reserved matters have to be applied for inside the first period and the development begun inside a second, measured from the last approval. A variation aimed at the wrong one of those two is an application aimed at nothing.

02 · The instruments

The four instruments

Three of these change a permission. The fourth is the one people most often mean when they say they want to change a condition, and it changes nothing at all.

Instrument 01

Non-material amendment

A change the authority is satisfied is not material. It amends the permission that already exists instead of granting another one, it can add, alter or remove conditions, and the decision is due within twenty-eight days of the application arriving.

Where it fails: there is no right of appeal, so a refusal sends the change back to the start.

Instrument 02

Section 73

An application to develop the same land without complying with a condition. The authority looks only at the conditions, and where it agrees it grants a new permission carrying the ones it thinks right. Removal counts as well as variation.

Where it fails: it cannot be used to push back the date by which the development has to be begun.

Instrument 03

A fresh application

Where the change is bigger than a condition can carry, the route is a new application for the whole scheme. The original permission stays live while it is determined, which makes it a fallback rather than a bridge that has been burned.

Where it fails: nothing is carried over. Every part of the scheme is open again, not only the part that moved.

Instrument 04

Approval of details

A condition requiring materials, drainage or landscaping to be approved is dealt with by submitting those details for approval. That submission costs a fee of its own, and it is the one most often mistaken for a change to the permission.

Where it fails: it alters nothing. It satisfies a requirement the permission had already imposed.

03 · The ceiling

When a change needs a new application

A section 73 has a ceiling, and it is not a matter of size. The application is for permission to build the same development on different conditions, so the words describing that development are fixed. Change them and you are asking for something the section cannot give.

The Court of Appeal settled that in 2019, in a case about wind turbines where the description named a height and the applicant tried to vary the plans condition to a taller one. The court held the description could not be altered this way. A second Court of Appeal decision in December 2024 went further and held that a condition imposed on a section 73 permission cannot contradict the description either.

The practical consequence is a test anyone can apply before spending a fee. Read the description of development on the decision notice. If the change makes that sentence untrue, no variation will reach it. Adding homes to a consented scheme is the everyday example: a number in the description is a number you cannot move by varying a condition, and the route is a fresh application for the larger scheme.

There is a tidy-up worth knowing about for older permissions. Some consents, particularly pre-2008 ones, carry no condition listing the approved drawings at all, which leaves nothing to vary. National guidance accepts that a non-material amendment can be used to add that condition, which then gives a section 73 something to bite on later.

Two further limits apply whichever route is taken. The biodiversity gain condition sits outside the reach of both, and has done since February 2024. And a non-material amendment reaches planning permission only, so alterations to a listed building need their own consent regardless of how small the change looks on a drawing.

Common questions

Changing a permission, answered

Who decides whether a change is non-material?

The local planning authority does, and nothing in the legislation tells it where the line sits.

There is no statutory definition of the term, because a change that is trivial on one scheme is obvious on another. What the Act does require is that the authority has regard to the change together with any previous changes made the same way, measured against the permission as it was originally granted. The test therefore tightens as a scheme accumulates them, so a permission already amended three times has less room left for the next one. Where an application is made, anyone else who owns the land, and any agricultural tenant, has to be told and gets fourteen days to write in.

What is a minor material amendment?

A working phrase rather than a legal one. It describes a change made by varying a condition under section 73.

Nothing in the Act creates a category called a minor material amendment. The national guidance uses the phrase only to describe what a section 73 application can achieve, not to create a species of application. It survives because it names a real gap in the reader's head: the change is too big to be waved through as non-material, but nobody wants to start the whole scheme again. Section 73 is the instrument that fills that gap, and calling the application by its section number rather than by the nickname avoids an argument with a validation officer about what was actually applied for.

Is section 73B available yet?

No. It was written into the Act in 2023 and had still not been brought into force as at August 2026.

Section 73B would allow an application for a permission that is not substantially different from one already granted, which is the middle route the current system does not have. It was inserted by the Levelling-up and Regeneration Act 2023 and is marked prospective on the statute book, meaning it needs a commencement order that has not been made. Until it is made, a change that section 73 cannot carry has only one route, which is a fresh application for the whole scheme. Anyone reading this after 2026 should check the position again before relying on it.

Can a prior approval be amended?

In practice yes. Councils have determined and granted amendments to prior approvals, though the route is less settled than it is for a full permission.

A barn conversion at Earlswood in Solihull is the clean example. The prior approval for two homes was given in August 2022; a non-material amendment redesigning the entrance hall, the first floor windows, part of the roof and the external materials was granted on 12 September 2023, twelve days after it went in. An office conversion at Leam Terrace in Leamington went the other way, varying one condition and removing another on a prior approval by application to the council. Neither is a substitute for asking the authority first, because practice differs between them.

Does changing a permission cost a fee?

Yes. Both routes carry a fee of their own, and the cheaper one is a small fraction of the more expensive.

A non-material amendment is the cheapest of these routes and a section 73 is priced against the scale of the development it varies, so the gap between them is wide enough to be worth a phone call before deciding. A fresh application is the expensive answer, and it is no longer possible to soften it by resubmitting free: the exemption that allowed one further application on the same site without a fee was revoked with effect from 6 December 2023. Fees are re-set every April, so check the current figure rather than a number in an old quote.

Can a council change a permission after granting it?

Yes, but rarely. A council may revoke or modify a permission by order, and it has to pay for doing so.

The power sits in section 97 of the Act and it is time limited: where the permission is for building work the order can only be made before those works are completed, and where it is for a change of use only before the use has changed. Compensation is payable to anyone who has spent money on work the order makes abortive, or who otherwise loses out by it, which is the practical reason the power is used so little. The everyday version of the same worry is much less dramatic: a condition that turns out to be unworkable is dealt with by an application to vary it, not by the council taking the permission back.

Can a permission be changed once building has started?

Yes. Once development has lawfully begun the permission does not lapse, and the routes to change it stay open.

That is the mirror image of the deadline, and it is the part most people have backwards. The three-year limit is a limit on starting, not on finishing and not on amending, so a scheme that has broken ground can still be varied years later. What does change is the practical cost: conditions already discharged were discharged against the drawings as they then stood, so a variation late in a build can put a discharged condition back in play. The sequence worth keeping is to settle the change, then check which conditions it disturbs, rather than the other way round.

Written by

Rickett Architects

A RIBA Chartered practice, working since 1970, with more than 2,500 projects behind it. Our senior architects take projects from first survey through planning to completion, for private clients, developers and landowners across the Midlands and well beyond it.