Unilateral Undertaking Planning: Section 106 Rules Explained

A unilateral undertaking in planning is a legally binding planning obligation given by a person with an interest in land under Section 106 of the Town and Country Planning Act 1990. Unlike a traditional Section 106 agreement, the local planning authority does not become a party to the unilateral undertaking.

Unilateral undertakings can be used to secure planning obligations connected with a proposed development, including financial contributions, restrictions on the use of land and specified works or activities. They can also be relevant during planning appeals where an outstanding planning obligation needs to be addressed.

Because a unilateral undertaking is a formal legal document and can create enforceable obligations affecting land, it should be prepared and reviewed carefully before it is signed.

 

What Is a Unilateral Undertaking in Planning?

A unilateral undertaking is a type of planning obligation made under Section 106 of the Town and Country Planning Act 1990.

The key difference between a unilateral undertaking and a Section 106 agreement is who becomes a party to the document.

With a Section 106 agreement, the relevant parties, normally including the local planning authority and persons with an interest in the land, enter into the agreement.

With a unilateral undertaking, the person or persons giving the planning obligation execute the undertaking without the local planning authority becoming a party.

The undertaking can contain legally binding commitments relating to the development or the use of land.

These may include:

• Financial contributions

• Affordable housing obligations

• Highway or transport contributions

• Open-space contributions

• Education contributions

• Restrictions on the use of land

• Requirements to carry out specified works or activities

• Other obligations necessary to make the development acceptable in planning terms

A unilateral undertaking therefore provides a mechanism for securing a planning obligation without requiring the local authority to execute the document as a party.

 

When Is a Unilateral Undertaking Used?

A unilateral undertaking may be appropriate where a specific planning obligation needs to be secured and the applicant can give that commitment without requiring reciprocal obligations from the local planning authority.

They can be particularly relevant where:

• the obligation is relatively straightforward;

• the applicant is willing to provide the required contribution or restriction;

• the local planning authority does not need to undertake corresponding obligations;

• a planning application requires a Section 106 obligation; or

• a planning appeal requires a planning obligation to address an identified planning issue.

A unilateral undertaking does not automatically speed up every planning application. Its usefulness depends on the circumstances of the development, the local authority’s requirements and whether the proposed obligation properly addresses the relevant planning issue.

 

What Is the Difference Between a Unilateral Undertaking and a Section 106 Agreement?

Both are forms of Section 106 planning obligation, but they are structured differently.

Section 106 Agreement

A Section 106 agreement is normally entered into between the local planning authority and the relevant person or persons with an interest in the land.

The terms are generally agreed between the parties before the document is executed.

Unilateral Undertaking

A unilateral undertaking is given by the person or persons providing the planning obligation.

The local planning authority does not become a party to the undertaking.

Key difference

The important distinction is therefore not simply whether the document relates to Section 106. Both can do so.

The difference is the structure of the legal obligation:

Section 106 agreement: the relevant parties enter into an agreement.

Unilateral undertaking: the person with the relevant interest in the land gives the planning obligation without the local planning authority becoming a party.

This distinction can make a unilateral undertaking suitable where the applicant needs to commit to a specific obligation but the authority does not need to make reciprocal commitments.

 

What Can a Unilateral Undertaking Include?

The contents of a unilateral undertaking depend on the development and the planning issue being addressed.

Section 106 planning obligations can include provisions that:

• restrict the development or use of land;

• require specified operations or activities to be carried out;

• require land to be used in a specified way; or

• require sums to be paid to the relevant authority.

Financial contributions

A unilateral undertaking may secure a financial contribution where the contribution is necessary to make the development acceptable in planning terms.

The document should clearly identify:

• the amount payable;

• the purpose of the contribution;

• the person responsible for payment;

• when payment becomes due; and

• any relevant trigger or phasing provisions.

Affordable housing

Where the relevant planning policies and legal requirements apply, affordable housing obligations may be secured through a planning obligation.

The precise mechanism will depend on the development, local planning policy and the terms required by the local planning authority.

Highway and transport contributions

A planning obligation may be used to secure contributions or works relating to highways and transport where the development creates an impact that requires mitigation.

Open-space and education contributions

Depending on the development and local planning requirements, obligations may also relate to open space, education or other infrastructure.

The obligation must still satisfy the applicable legal and policy tests.

 

What Legal Tests Apply to a Planning Obligation?

A unilateral undertaking is not simply a mechanism for imposing any contribution or requirement on a developer.

Planning obligations must satisfy the applicable legal and policy requirements.

The key tests are that an obligation must be:

1. Necessary to make the development acceptable in planning terms.

2. Directly related to the development.

3. Fairly and reasonably related in scale and kind to the development.

These tests are important when considering both the nature of an obligation and the amount of any financial contribution.

Before signing an undertaking, a developer should understand why the obligation is required and how the proposed contribution or restriction relates to the development.

 

How Do You Prepare and Submit a Unilateral Undertaking?

Preparing a unilateral undertaking requires more than simply signing a document promising to make a payment or carry out works.

1. Check the planning application

First, establish the development proposal to which the undertaking relates and identify the planning issue that the obligation is intended to address.

The obligation should correspond to a clearly defined development proposal.

2. Identify the required planning obligation

Determine what obligation is required and why.

This could involve a financial contribution, restriction on the use of land, specified works or another planning obligation connected with the development.

3. Check land ownership and title

The person giving the undertaking must have the relevant legal interest in the land.

Ownership and title information should therefore be checked carefully before the deed is prepared.

This can be particularly important where land has:

• multiple owners;

• leaseholders;

• mortgage interests;

• development agreements;

• options; or

• other legal interests.

4. Draft the undertaking

The document should clearly identify the land, parties, legal basis of the obligation, obligations being imposed and the circumstances in which each obligation takes effect.

The wording should also make payment dates, triggers and other requirements sufficiently clear.

5. Execute the deed correctly

A Section 106 planning obligation is a formal legal instrument and must be properly executed as a deed.

Errors in execution can create problems with the validity or enforceability of the document.

6. Submit the undertaking

The executed or draft undertaking should be submitted in accordance with the requirements of the relevant local planning authority or, where applicable, the Planning Inspectorate.

For planning appeals, the Planning Inspectorate provides specific guidance on submitting planning obligations, including unilateral undertakings.

7. Keep a record of the final document

The developer or landowner should retain the final executed undertaking together with the relevant title documents, planning permission and correspondence.

This helps establish exactly what obligations were given and when they take effect.

 

Can a Unilateral Undertaking Be Used During a Planning Appeal?

Yes.

A unilateral undertaking planning appeal can be relevant where a planning application has been refused partly because a necessary planning obligation was not secured.

For example, an appellant may offer a unilateral undertaking to provide a financial contribution or impose a restriction intended to address an identified planning issue.

The Planning Inspectorate’s guidance expressly recognises both Section 106 agreements and unilateral undertakings in connection with planning appeals.

However, a unilateral undertaking does not automatically resolve an appeal.

The appeal will still be assessed on its planning merits, and the undertaking must adequately address the relevant planning obligation.

Timing is also important. Ownership information, drafting, execution and submission requirements should be considered early rather than left until the final stage of an appeal.

 

Does a Unilateral Undertaking Automatically Grant Planning Permission?

No.

A unilateral undertaking does not itself grant planning permission.

Instead, it can secure planning obligations that may form part of the measures required to make a development acceptable in planning terms.

Planning permission and the planning obligation are therefore separate legal matters.

A development may still be refused for other planning reasons even where an undertaking has been offered.

 

Can a Unilateral Undertaking Be Changed or Withdrawn?

A unilateral undertaking should not be treated as a document that can simply be withdrawn whenever the developer changes their mind.

Once properly executed and effective, it can create legally binding planning obligations.

The ability to modify or discharge a planning obligation depends on the applicable statutory provisions and the circumstances of the case.

Under Section 106A, planning obligations may in certain circumstances be modified or discharged by agreement with the local planning authority or through an application to the authority.

There can also be a right of appeal where an application for modification or discharge is refused.

Because changing a planning obligation after execution can be difficult, the wording should be reviewed carefully before the undertaking is signed.

 

What Happens If Planning Permission Is Refused?

The consequences of a unilateral undertaking following refusal can depend on the wording of the document and the circumstances in which it was given.

Before signing, developers should establish:

• when the undertaking becomes operative;

• what event triggers each obligation;

• whether the obligations depend on planning permission being granted;

• what happens if permission is refused;

• what happens if an appeal is submitted;

• what happens if the development is never implemented; and

• whether the obligation contains appropriate provisions dealing with its operation.

The effect of refusal should therefore be considered during drafting rather than after the planning decision has been made.

 

How Much Does a Unilateral Undertaking Cost?

There is no single fixed cost for a unilateral undertaking.

The overall cost can depend on:

• the size and complexity of the development;

• the number of obligations;

• the value of financial contributions;

• the complexity of the legal drafting;

• the number of landowners;

• title issues;

• negotiations with the local planning authority;

• whether the matter is part of a planning appeal; and

• any council legal or monitoring fees.

For a straightforward undertaking, the legal work may be relatively limited. More complex developments can require considerably more work.

Developers should therefore consider the cost of preparing the undertaking alongside the wider planning and development budget.

 

How Long Does a Unilateral Undertaking Take?

There is no universal timeframe.

A straightforward undertaking may be prepared relatively quickly, while more complicated cases can take longer.

Potential causes of delay include:

• multiple landowners;

• unclear title information;

• disagreement over the obligation;

• disputes about financial contributions;

• complex trigger mechanisms;

• amendments requested by the local planning authority;

• execution problems; and

• planning appeal deadlines.

Starting the process early can reduce the risk of the undertaking becoming a procedural problem for the application or appeal.

 

Should a Solicitor Review a Unilateral Undertaking?

Legal review can be particularly important where the undertaking creates substantial financial or development obligations.

A solicitor can review matters including:

• the proposed contribution;

• the legal wording;

• payment triggers;

• implementation triggers;

• land ownership;

• enforcement provisions;

• successor obligations;

• modification or discharge provisions;

• conditional clauses; and

• the relationship between the undertaking and the planning permission.

The objective is not simply to obtain planning permission but to ensure that the developer understands exactly what legal obligations they are accepting.

 

Unilateral Undertaking Planning: What Should You Check Before Signing?

Before signing a unilateral undertaking, consider the following:

1. What exactly am I agreeing to?

2. Why is the obligation necessary?

3. How is any financial contribution calculated?

4. When does payment become due?

5. What event triggers the obligation?

6. Does the obligation satisfy the applicable planning tests?

7. Who owns the land?

8. Who needs to execute the deed?

9. Could the obligation affect successors in title?

10. What happens if planning permission is refused?

11. What happens if the development is never implemented?

12. Can the obligation be modified or discharged?

13. Are there other Section 106 obligations?

14. Could Community Infrastructure Levy also apply?

15. Does the local planning authority have specific requirements for unilateral undertakings?

These checks can help identify legal and financial issues before the document becomes binding.

 

Unilateral Undertaking vs CIL

A unilateral undertaking and the Community Infrastructure Levy (CIL) are different planning mechanisms.

A unilateral undertaking is a form of planning obligation under Section 106.

CIL is a separate planning charge that may apply to certain qualifying development.

Depending on the development and local charging arrangements, both mechanisms can be relevant.

Developers should therefore assess potential Section 106 obligations and CIL liabilities when considering the overall financial implications of a project.

 

Need Legal Advice on a Unilateral Undertaking?

A unilateral undertaking in planning law can create important legal and financial obligations for developers and landowners.

Whether you are preparing a planning application, responding to a planning obligation or pursuing a planning appeal, the document should be drafted with the specific development, land ownership and planning requirements in mind.

Charrette Law advises property owners, landowners and developers on planning matters, including unilateral undertakings, Section 106 agreements, planning applications and planning appeals.

If you have been asked to provide a unilateral undertaking or have received a draft that requires review, obtain legal advice before signing a document that could create binding obligations.

 

Frequently Asked Questions About Unilateral Undertakings

What is a unilateral undertaking in planning?

A unilateral undertaking is a legally binding planning obligation given by a person with an interest in land under Section 106 of the Town and Country Planning Act 1990. The local planning authority does not become a party to the undertaking.

Is a unilateral undertaking the same as a Section 106 agreement?

No. Both can operate as Section 106 planning obligations, but their structure is different. A Section 106 agreement is entered into by the relevant parties, while a unilateral undertaking is given by the person or persons providing the obligation without the local planning authority becoming a party.

Is a unilateral undertaking legally binding?

Yes. A properly executed unilateral undertaking can create legally binding planning obligations relating to the land.

Can a unilateral undertaking secure affordable housing?

Potentially. Affordable housing can be secured through a planning obligation where the relevant planning policy and legal requirements are satisfied.

Can I use a unilateral undertaking instead of a Section 106 agreement?

It depends on the circumstances and the requirements of the local planning authority. A unilateral undertaking may be suitable where a specific obligation can be provided without reciprocal commitments from the authority, but it is not automatically appropriate for every development.

Can a unilateral undertaking be used during a planning appeal?

Yes. Unilateral undertakings can be used in connection with planning appeals where a planning obligation is relevant to the issues being considered.

Can a unilateral undertaking be changed?

Planning obligations may be capable of modification or discharge in certain circumstances. The applicable statutory procedure and the wording of the obligation should be considered before assuming that an undertaking can be changed.

Does a unilateral undertaking run with the land?

Planning obligations can bind successors in title, depending on the nature of the obligation and the relevant legal interests in the land. The undertaking should therefore be reviewed carefully before signing.

Does a unilateral undertaking grant planning permission?

No. A unilateral undertaking is a planning obligation. It does not itself grant planning permission, and the underlying planning application or appeal must still be determined on its planning merits.

How much does a unilateral undertaking cost?

There is no standard cost. Fees can depend on the complexity of the undertaking, the development, financial contributions, title arrangements, legal work and any local authority fees.

Can a unilateral undertaking be used instead of negotiating with the council?

A unilateral undertaking can sometimes avoid the need for a bilateral Section 106 agreement where the applicant can give the necessary obligation without the local authority becoming a party. However, applicants may still need to discuss the wording, amount, triggers and procedural requirements with the authority.

Should I get legal advice before signing a unilateral undertaking?

Where the undertaking creates significant financial, development or land-use obligations, legal review can help identify the consequences of the commitment before it becomes binding.

Conclusion

A unilateral undertaking in planning can provide a practical way for developers and landowners to secure planning obligations under Section 106 without entering into a bilateral Section 106 agreement with the local planning authority.

However, signing an undertaking creates potentially binding legal obligations, so the document should be considered carefully before execution. The nature of the obligation, payment triggers, land ownership, planning permission, appeal circumstances and potential future implications should all be understood.

Whether a unilateral undertaking is appropriate will depend on the individual development and the planning obligations required. Professional planning and legal advice can help ensure that the undertaking is properly drafted and that the obligations being offered are necessary, directly related to the development and proportionate to its scale and impact.

If you are preparing a planning application or appeal and have been asked to provide a unilateral undertaking, Charette Law can advise on the planning and legal issues involved, including Section 106 obligations, planning applications and appeals.