Deed of variation or a section 106A application

Changing a planning obligation has two routes and they are not alternatives you pick on convenience. A deed of variation is a negotiated agreement available at any time, where the authority has a free hand to say no. An application under section 106A of the Town and Country Planning Act 1990 is a statutory route available only after the relevant period has expired, normally five years from the date the obligation was entered into, and it is decided against a narrow statutory test that has very little to do with whether your scheme now stacks up.

That distinction catches out more people than any other point in obligation practice. Applicants reach for section 106A expecting a viability hearing and get a question about whether the obligation still serves a useful purpose.

What a deed of variation requires

A deed of variation is a contract. Section 106A(1)(a) allows an obligation to be modified or discharged by agreement between the authority and the person against whom it is enforceable, and there is no time restriction and no statutory test.

What it needs is everybody's signature. All parties with an interest in the land bound by the original obligation, which can mean a former owner, a management company and sometimes a statutory undertaker. Any mortgagee whose consent the original deed required. The authority itself, acting through whoever holds delegated authority for obligations, which on a material change is often a committee rather than an officer, and our note on committee determination against a delegated decision explains how that split works.

The practical constraints are policy and precedent. An authority asked to reduce an affordable housing obligation is being asked to depart from its adopted policy, and it will want the same evidence it would want on a new application. An authority asked to change a trigger point from before occupation to before occupation of plot 30 will often agree quickly, because nothing of substance changes.

Timescales are driven by the authority's legal team rather than by any statutory clock. Six to twelve weeks is normal for an uncontentious variation. A contentious one takes as long as it takes.

When the authority will not agree

Three refusals recur.

A reduction in affordable housing provision or tenure mix, where the authority treats agreement as setting a precedent other applicants will cite.

Removal of a contribution the authority has already allocated or spent against, where it has a programme commitment behind the money.

A change that would need a fresh planning judgement, for example dropping a highway improvement, where officers will say the right route is a new application rather than a variation of the obligation.

The honest position is that a deed of variation works well for mechanics and badly for substance. Trigger points, payment profiles, the definition of occupation, indexation, the identity of the affordable housing provider, step-in rights: all routinely agreed. The quantum of affordable housing: rarely.

The statutory route and its timing

Section 106A(3) lets a person against whom the obligation is enforceable apply to the authority to have it modified or discharged, but only after the relevant period has expired. That period is five years beginning with the date the obligation was entered into, unless a different period is prescribed.

Two consequences follow. An obligation completed two years ago cannot be attacked this way at all. And the clock runs from the date of the deed, not from the date of the permission or the start of development, so check the deed's execution date rather than the decision notice.

The test the authority applies

Section 106A(6) gives the authority three outcomes on an application. It may determine that the obligation shall continue without modification. It may determine that the obligation no longer serves a useful purpose and shall be discharged. Or it may determine that the obligation continues to serve a useful purpose but would serve that purpose equally well if modified in the way applied for, in which case it modifies it accordingly.

Read that carefully. The question is about the purpose of the obligation, not about the economics of the development. An affordable housing obligation that the authority still wants, and which still delivers affordable housing, continues to serve a useful purpose however unviable the scheme has become. You cannot get there by showing the numbers no longer work.

Where the route does work is on obligations that have been overtaken by events. A contribution towards a school expansion that has been built and funded another way. A travel plan monitoring fee for a use that no longer exists. A restriction tied to a phase of development that was never built and cannot now be built. A requirement to provide a facility the authority has since said it does not want.

The modification outcome is also constrained. The authority can only modify in a way that serves the original purpose equally well, so you cannot use it to substitute a smaller obligation of a different kind.

Appeal rights and their limits

Section 106B provides an appeal to the Secretary of State where the authority determines that the obligation shall continue without modification, or fails to determine the application within the prescribed period. The appeal is decided on the same statutory test, so an appeal that argues viability loses for the same reason the application did.

There is no appeal against a refusal to enter into a deed of variation, because there is nothing to appeal against. A refusal to negotiate is not a decision. Judicial review is theoretically available against an authority acting unlawfully in exercising its discretion, and it is rarely the right answer on cost and timescale.

One route that is sometimes forgotten: a fresh planning application for a revised scheme, with a new obligation negotiated from scratch, puts the whole package back on the table in a way neither route above does. It costs a fee and a determination period and it is frequently the cleanest answer.

Evidence for a viability based change

Where viability is the real driver, the realistic route is a deed of variation supported by proper evidence, not a section 106A application.

That means a viability assessment prepared to the approach national guidance expects, with the inputs transparent and the assumptions capable of being tested by the authority's own adviser. Expect the authority to commission a review at your cost, expect its adviser to challenge the gross development value and the benchmark land value above everything else, and expect a late stage review mechanism to be proposed so that any recovery in values is shared.

Councils expect a suitably qualified author for this work and professional review is strongly advised. The relationship between the obligation and the policy position should also be set out in an affordable housing statement rather than left implicit in the viability appendices.

One honest uncertainty. A temporary statutory route introduced in 2013 that allowed affordable housing requirements in obligations to be reviewed on viability grounds is no longer available, and the renegotiation of obligations now runs entirely through authority discretion and the narrow section 106A test. Practitioners who learned the system during that window sometimes still reach for a mechanism that has gone.

Start with the deed's execution date, then decide which route is even open to you. Everything else follows from that. The full index of report types covers the supporting evidence either route needs.

This is general guidance, not legal advice; take advice from a planning solicitor on any modification or discharge of a planning obligation 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.