Non-material amendment: the narrow route to a small change

A non-material amendment is a change to an existing planning permission that the local planning authority is satisfied is not material. The power sits in section 96A of the Town and Country Planning Act 1990, it is quick, it costs far less than a fresh application, and it has no statutory definition of the thing it turns on. Whether your change is non-material is a judgement for the authority, made on the facts of that permission, and there is no appeal if they say no.

That combination makes section 96A useful and unreliable in equal measure. Architects use it constantly for window positions, material substitutions and drawing corrections. It fails whenever the change touches something a consultee or a neighbour commented on.

What the power actually does

Section 96A lets an authority make a change to any planning permission relating to land in its area, provided it is satisfied the change is not material. The power extends to imposing new conditions, and to removing or altering existing ones, as part of the amendment.

The amendment attaches to the original permission. No new permission is issued, the original decision notice remains the operative consent, and the amendment is recorded in a separate notice that has to be read alongside it. Keep both together in the project file, because the pair of documents is what a purchaser's solicitor, a building control body and a warranty provider will ask for.

Procedurally it is light. The application is made on the prescribed form with a fee set by the national fee regulations, which are indexed annually, so check the current schedule rather than a figure in an old fee note. There is a 28 day determination period, extendable by agreement. There is no statutory requirement for publicity or consultation, although some authorities notify neighbours as a matter of local practice, and there is no right of appeal against a refusal.

Two limits are worth knowing before you start. The power cannot be used to extend the time limit for implementation of a permission. And authorities generally decline to use it to alter the description of development, on the basis that changing the description changes the permission rather than amending it.

Where it comes from and what it does not define

The section was inserted by the Planning Act 2008 to fill a gap. Before it, there was no statutory mechanism for a small change, and practice relied on informal letters from officers confirming that a departure from the approved drawings was acceptable. Those letters had no legal effect, which caused real problems on sale and at discharge of condition stage.

What Parliament did not do was define "non-material". The statute requires the authority to have regard to the effect of the change, together with any previous changes made under the same power, on the planning permission as originally granted. That cumulative limb is the one people forget. Three successive amendments, each defensible on its own, can take a scheme to a point where the fourth is refused because the authority now looks at the aggregate.

Planning Practice Guidance confirms that there is no statutory definition and that materiality is a matter of fact and degree for the authority in each case. That is unhelpful if you want certainty and sensible if you think about the range of permissions the power has to cover.

How an authority decides materiality

Officers work through a familiar set of questions, and you can anticipate all of them.

• How large is the change relative to the permitted scheme? A 300 millimetre shift on a 40 metre industrial unit is a different proposition from the same shift on a mews house.
• Is the change visible from the public domain, and does it alter the appearance that was assessed?
• Does it affect a neighbour relationship? Anything that moves a window, raises a ridge or extends towards a boundary engages amenity, and a change that worsens an overbearing effect will not be treated as non-material.
• Does it touch a matter that a statutory consultee commented on, or that was the subject of an objection or a committee debate?
• Would it require a condition to be reworded, or make an approved document inaccurate?
• What is the cumulative effect with earlier amendments to the same permission?

Changes that usually succeed: substituting a brick or a roof tile for a close match, correcting a dimension or a drawing error, repositioning internal walls, minor adjustments to levels where there is no visual consequence, adding or relocating a rooflight on a rear slope, and tidying the drawing schedule in a condition.

Changes that usually fail: increases in floorspace or unit numbers, additional windows facing a neighbour, a change of materials that alters the character of the elevation, moving a building closer to a boundary, altering an access, and anything affecting a listed building or a protected tree.

An illustrative example

Take an illustrative case. Permission is granted for a pair of semi-detached houses, with conditions requiring compliance with the approved drawings, a materials schedule and a landscaping plan.

During construction the contractor finds that the specified facing brick has a 14 week lead time and offers an alternative from a different manufacturer in the same colour range and format. The elevations are otherwise unchanged. That is a textbook section 96A amendment: it affects only the materials condition, the appearance is materially the same, and no consultee or neighbour interest is engaged.

In the same scheme, the client asks to raise the ridge by 400 millimetres to gain head height in the loft. The rear elevation faces a neighbouring garden, and an objection at application stage was about the height of the rear roof slope. That is not a non-material amendment, whatever the dimension looks like in isolation, because it goes to the point that was in issue. The route there is a section 73 application or a fresh application.

This example is illustrative. The judgement on any real permission depends on its own planning history.

What it gets confused with

Four things, regularly.

A section 73 application varies or removes a condition, and because most schemes are tied to approved drawings by condition, it is the normal route for a change that is material but modest. It is often called a minor material amendment, which is a practice term rather than a statutory one. It takes eight weeks, involves publicity and consultation, carries a right of appeal, and results in a new permission sitting alongside the original. It cannot be used to extend a time limit either.

A discharge of conditions application supplies information a condition requires. It does not change the permission, and it is not a way to introduce a design change by the back door. Officers notice.

A new power at section 73B, inserted by the Levelling-up and Regeneration Act 2023, allows an application to alter a permission where the development would be substantially the same. Check whether it is in force and how the authority is applying it before planning around it, because provisions in that Act have been brought into force in stages.

And severing a condition is a different exercise again, with its own consequences for the remainder of the permission, set out in severing an unlawful planning condition.

Checking the position before you apply

Ask, informally, first. Most case officers will say whether they regard a proposed change as non-material if you send a short note with a before and after drawing, and that conversation costs nothing and takes a week. A refusal under section 96A is not appealable, so you want to know in advance.

Then assemble the application properly:

1. A covering note identifying the permission by reference and date, and listing every amendment previously made to it.
2. A schedule of the approved drawings against the proposed replacements, by number and revision.
3. Each change described in one line, with the dimension or specification stated.
4. A short assessment of why each change is not material, addressing visibility, neighbour amenity and any consultee interest.
5. The reworded condition, if a condition needs to change, drafted for the officer.

That fourth item is what gets the application determined in 28 days rather than refused as insufficiently explained. And if the honest answer is that the change is material, go to section 73 at the outset rather than losing six weeks on a refusal.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it.

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