Budgeting a section 73 variation on a live permission

A section 73 application looks like the lowest-cost way to change a permission, and on a live site it usually is not. The application fee is modest. What costs money is everything that travels with it: refreshed technical reports, a fresh consultation, a recalculated levy position, a deed of variation to the section 106 agreement, and the conditions you had already discharged, which may need discharging again against the new permission. Budget for those five things and the exercise is predictable. Budget for the fee alone and it is not.

What triggers the need for a variation

Section 73 of the Town and Country Planning Act 1990 allows an application for permission to develop without complying with a condition previously imposed. The council can grant it subject to different conditions, or refuse, and the result is a new planning permission that sits alongside the original rather than replacing it.

What it cannot do is change the description of the development. Following the Court of Appeal's decision in Finney v Welsh Ministers in 2019, a condition cannot be varied in a way that conflicts with the operative part of the permission, so a permission for 40 dwellings cannot become one for 45 by this route. Section 73 also cannot be used to extend the time limit for implementation.

For trivial changes, section 96A allows a non-material amendment with no consultation and a short determination period. The line between non-material and minor material is a judgement, and the officer's view of it decides which route and therefore which budget applies.

Fee and supporting documents required

The application fee for varying or removing a condition is set in the national fee regulations and indexed, so check the current schedule rather than a figure from a previous file. It is a small part of the total.

The validation requirements are the part people underestimate. An authority treats a section 73 application as an application, which means its local validation list applies: revised drawings, a covering statement explaining the change and why it is acceptable, and whichever technical documents the changed element affects. On a scheme of any size that usually means a revised Planning Statement addressing the current development plan, not the plan that was current when the original permission was granted.

That last point costs money. If the local plan has been adopted or reviewed since the original decision, the policy framework has moved, and the officer assesses the new application against today's policies.

Reports that have to be refreshed

Work through the evidence base and ask, for each document, whether it would still be accepted if submitted today.

• Ecology surveys age. Most authorities treat data more than two or three seasons old as needing an update, and a protected species licence cannot rest on a stale baseline.
• Flood risk assessments are recalculated against the current climate change allowances, which are revised periodically. An assessment prepared to superseded allowances will be challenged.
• Transport work may need new trip rates or a revised junction assessment if the surrounding network has changed or if a newer data set is expected.
• Energy statements are tested against the Building Regulations in force, and Part L has moved.
• Contamination and geotechnical reports usually survive unchanged, unless the layout moves the building over a different part of the site.

Budget the refresh selectively. A variation to a materials condition does not require the ecology to be redone. A variation to the approved layout probably does.

Levy and obligation consequences

Two mechanisms bite here, and both are easy to miss.

The Community Infrastructure Levy is recalculated for the new permission. The regulations deal with section 73 permissions specifically, so the chargeable amount is worked out for the amended scheme with credit for the original, but indexation is applied and the liability notices are reissued. Where floorspace increases, the additional liability is real money, and where instalment dates restart the cash flow changes. Read the liability notice that follows carefully, because the payment clock may not be where you expect.

The section 106 agreement attaches to the original permission, not the new one. Unless the deed is drafted to bind future permissions, a deed of variation or a supplemental agreement is needed so that the obligations apply to the section 73 permission. Legal fees for that, including the council's, belong in the budget, along with the authority's own monitoring arrangements.

Biodiversity gain implications

This is the item that has changed most recently. Permissions granted before the biodiversity gain condition regime applied are treated differently from new applications, and the regulations include transitional arrangements for section 73 applications relating to those earlier permissions.

The financial exposure is large enough to check before applying rather than after. If a variation brings a scheme into the gain regime, you are buying a metric exercise, a habitat management commitment lasting 30 years and possibly off-site units, none of which was in the original appraisal. Confirm the current position with the authority and with an ecologist, because the answer depends on the date of the original application and on what is being varied.

Programme effect on a live site

On a site where work has started, time is the real cost. A section 73 application carries the same determination periods as any other, so eight weeks for a minor and 13 for a major, plus the 21-day publicity period, plus the drafting of any deed. Three to four months from instruction to a usable permission is a realistic planning assumption, and it can be longer where a committee is involved.

Then there is the discharge position. Conditions discharged under the original permission are not automatically discharged under the new one, and the new permission will carry its own numbering. Ask the officer to carry approvals across in the decision notice or by a confirmatory letter, and check the wording before you rely on it. A contractor stood down while a previously approved drainage detail is re-approved is an expensive way to learn this.

Budgeting the whole exercise

Build the budget in six lines rather than one.

Against that, weigh the alternative. Sometimes the better answer is a fresh full application, particularly where several conditions need changing and the description of development no longer fits. Sometimes it is to build what was approved. The cost of getting an application invalidated is a useful comparison, because the same validation discipline applies.

One honest caveat: the levy and biodiversity positions on variations are the two areas where authorities and applicants most often disagree, and the answer can turn on dates rather than on planning merits. Ask the specific question in writing before you submit. 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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