Unilateral undertakings when a section 106 is refused
A unilateral undertaking lets an appellant put an obligation before an inspector without the council signing anything. What it has to contain and when it has to arrive.
A unilateral undertaking is the appellant's answer to a refusal reason that says the necessary planning obligation was never secured. It is a deed given by the person with an interest in the land, without the council as a party, and it is the standard way to put an obligation before an inspector when the council will not or cannot complete an agreement in time.
The test it has to pass is statutory. Under regulation 122 of the Community Infrastructure Levy Regulations 2010, an obligation may only be a reason for granting permission where it is necessary to make the development acceptable in planning terms, directly related to the development, and fairly and reasonably related in scale and kind.
Why applications are refused for want of an obligation
The usual sequence is mundane. Officers recommend approval subject to a section 106 agreement. The agreement is not completed by the determination date. The council refuses rather than letting the application drift, and the refusal reason recites that contributions towards affordable housing, education or open space have not been secured.
Sometimes the reason is a disagreement about what should be paid. More often it is timing, solicitors and an applicant who left the heads of terms until week six.
Either way, the refusal reason is capable of being cured. That is what makes these appeals different from an appeal about design or harm to the Green Belt, where the disagreement is substantive.
Unilateral undertakings and bilateral agreements
A bilateral agreement is made between the council and everyone with an interest in the land. It can include obligations on the council, it can be tailored through negotiation, and it needs the council's signature.
A unilateral undertaking is given by the landowner alone. It binds the land, it is enforceable by the council, and the council does not need to sign it. That last point is the whole reason it exists. An appellant who cannot get a council's legal team to engage before the appeal deadline can still put a properly executed deed in front of the inspector.
The trade-off is that a unilateral undertaking cannot bind the council to anything, so it cannot include a clawback mechanism requiring the council to repay unspent contributions unless the drafting is careful about how that operates.
Meeting the three statutory tests
Inspectors apply regulation 122 directly, and they refuse to give weight to obligations that fail it.
Necessary means the development would be unacceptable without it. An offer of a contribution towards something the council would like but does not need fails at this limb, however generous it looks.
Directly related means the obligation addresses an impact of this development. A contribution towards a library three miles away, unconnected to the occupiers of these houses, does not.
Fairly and reasonably related in scale and kind means proportionate. A contribution calculated by a formula in an adopted supplementary planning document usually clears this limb, provided the formula is applied to the right figures.
Justify each limb explicitly in the appeal statement, obligation by obligation. A Planning Statement or appeal statement that lists the obligations and then addresses regulation 122 in a table is doing the inspector's work for them, which is the point.
Where the obligation is reduced or removed on viability grounds, the evidence for that is a Viability Assessment prepared to recognised professional standards, and the council is entitled to test it.
Drafting and execution before the deadline
The drafting problems are almost always the same, and they are all avoidable.
- Identify every person with a legal interest in the land from official copies of the register, and make each of them a party. A mortgagee that has not consented can defeat the whole deed.
- Define the appeal by its reference number and the application by its reference and date, so there is no doubt what the obligation attaches to.
- Make the obligation conditional on the appeal being allowed and on implementation, so it does not bite if the appeal fails.
- Tie triggers to identifiable events: commencement, occupation of a numbered dwelling, or a date certain. Avoid triggers that depend on the council doing something.
- Index the sums, state the base index and date, and say what happens if the index is discontinued.
- Execute it properly as a deed, with the correct attestation for a company, an individual or a trustee.
Send the executed deed, the official copies and a plan. Send a certified copy rather than the original unless the Inspectorate asks otherwise.
Get the plan right as well. An obligation that refers to land shown edged red on a plan that does not match the appeal site plan is an obligation with a defect in it, and the point will be taken.
Timing within the appeal programme
For written representations, submit the executed undertaking with the statement of case or by the date the Inspectorate sets. Leaving it to the final comments stage risks the council having no opportunity to respond, which is a fair reason for an inspector to disregard it. The full sequence is set out in the guide to written representations appeals and the full timetable.
At a hearing or inquiry, the deed has to be completed before the event closes. Inspectors regularly set a deadline of a few days after the close for the engrossed deed, and then decide on the basis of it.
Where the council is negotiating in parallel, agree the heads of terms in the statement of common ground so the inspector can see what is and is not in dispute. The note on statements of common ground at hearings and inquiries sets out what belongs there.
Contingent and alternative obligations
Sometimes the dispute is whether an obligation is needed at all. The appellant says the contribution fails regulation 122. The council says it is necessary.
The practical answer is a contingent obligation: an undertaking that takes effect only if the inspector concludes that the contribution is necessary, while the appellant maintains that it is not. Inspectors accept this structure readily, and it avoids the appellant having to choose between paying something they dispute and risking dismissal.
Alternative obligations work the same way where there are two ways to mitigate an impact, for example on-site provision or a commuted sum. Draft both, make each conditional on the inspector's finding, and explain the structure in a covering note.
Where the inspector gives the obligation no weight
Five recurring reasons. The deed is a draft rather than an executed document. A party with an interest in the land is missing. The obligation duplicates something already secured by the levy or by a condition. The obligation fails one of the regulation 122 tests. Or the triggers are so uncertain that the obligation could never be enforced.
There is a costs dimension too. Where a council refuses for want of an obligation, and the appellant then provides a compliant undertaking that the council accepts, an application for costs against the council may follow if the council behaved unreasonably in not completing an agreement. The reverse also applies to appellants who produce a deed at the last moment.
One practical note on drafting time. An engrossed deed with three parties and a mortgagee takes weeks rather than days, because the mortgagee's solicitors work to their own timetable and will want a fee undertaking before they look at anything. Start the title work when the appeal is lodged, not when the statement of case is due.
Keep the obligation as short as the subject allows. Long deeds with elaborate review mechanisms invite argument about enforceability, and an inspector reading a 40 page undertaking for a contribution towards a play area will wonder why.
What the obligation does not do is fix a scheme that is unacceptable for other reasons. It removes one refusal reason. The conditions the inspector then imposes are a separate matter, covered in the note on conditions imposed by an inspector after an appeal is allowed.
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
What is a unilateral undertaking?
A planning obligation under section 106 of the Town and Country Planning Act 1990 given by the person with an interest in the land alone, without the local planning authority as a party. It binds the land and is enforceable by the council, which is why it can be completed and submitted at appeal without the council's signature.
What are the three tests an obligation must meet?
Under regulation 122 of the Community Infrastructure Levy Regulations 2010, an obligation may only be a reason for granting permission where it is necessary to make the development acceptable in planning terms, directly related to the development, and fairly and reasonably related in scale and kind. Inspectors apply all three and disregard obligations that fail.
When must the undertaking be submitted?
For written representations, with the statement of case or by the date the Inspectorate sets, so the council has a chance to respond. At a hearing or inquiry it must be completed before the event closes, though inspectors often allow a short period afterwards for the engrossed deed to be sent in.
Can I offer an obligation while arguing it is not needed?
Yes. A contingent undertaking takes effect only if the inspector concludes the obligation is necessary, while the appellant maintains that it is not. Inspectors accept this structure, and it avoids having to choose between paying a disputed contribution and risking dismissal of the appeal.
Why do inspectors sometimes give an undertaking no weight?
Commonly because it is a draft rather than an executed deed, because a person with an interest in the land is not a party, because it duplicates something already secured by condition or by the levy, because it fails one of the regulation 122 tests, or because the triggers are too uncertain to be enforceable.
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.