A planning application can be acceptable in principle but still encounter difficulties because certain development impacts have not been adequately addressed. A proposal may require a financial contribution towards local infrastructure, restrictions on how a property is occupied or a commitment to provide a particular planning benefit before permission can be granted.
In such circumstances, a unilateral undertaking can provide a practical legal mechanism for addressing specific planning concerns without requiring the developer and local planning authority to negotiate a conventional Section 106 agreement.
For landowners and developers, understanding when this approach is appropriate can make a difference to the progress of a planning application, particularly where negotiations have become a source of delay or where a planning appeal is being considered.
Rather than treating a unilateral undertaking as simply another planning document, it is useful to understand how it can secure legally enforceable commitments and support a development proposal.
When a Unilateral Undertaking Can Help Move a Planning Application Forward
A unilateral undertaking is a planning obligation made under Section 106 of the Town and Country Planning Act 1990. Unlike a conventional Section 106 agreement, it is executed by the person or persons giving the obligations without requiring the local planning authority to become a signatory.
This distinction can be useful where a developer is willing to accept specific obligations and the authority does not need to undertake reciprocal commitments.
For example, a proposed residential development may require a financial contribution towards local transport improvements. Instead of negotiating a full agreement, the developer may offer a unilateral undertaking committing to make the relevant payment at an agreed stage of the development.
Other potential uses include:
-
Financial contributions towards local infrastructure.
-
Restrictions on the use or occupation of particular properties.
-
Commitments relating to affordable housing.
-
Obligations to undertake specified operations or activities on the land.
-
Restrictions intended to mitigate the effects of a proposed development.
However, the suitability of this approach depends on the nature of the obligation, the planning authority’s requirements and the circumstances of the application.
Why Developers May Choose a Unilateral Undertaking Instead of a Section 106 Agreement
The main attraction of a unilateral undertaking is that it can provide a more direct route to securing obligations where the developer is the only party required to make legally binding commitments.
A traditional Section 106 agreement involves the relevant parties, usually including the developer and local planning authority, negotiating and executing the agreement. This may involve discussions about payment arrangements, implementation dates, monitoring provisions and other responsibilities.
A unilateral undertaking can reduce some of this negotiation where the obligations are straightforward and do not require the authority to promise anything in return.
This can be particularly useful in planning appeals. Where an application has been refused or an appeal is being considered, the applicant may submit a unilateral undertaking to demonstrate a willingness to address particular planning concerns.
Nevertheless, submitting an undertaking does not automatically resolve planning objections. The document must address a genuine planning issue and satisfy the relevant legal and policy requirements.
The Planning Tests That Determine Whether an Undertaking Is Acceptable
A developer cannot simply offer any contribution or restriction and expect it to be accepted as a reason for granting planning permission.
Planning obligations must satisfy three established tests. They must be:
-
Necessary to make the development acceptable in planning terms: The obligation must address an identified planning impact that would otherwise make the proposal unacceptable.
-
Directly related to the development: There must be a clear connection between the proposed development and the obligation being offered.
-
Fairly and reasonably related in scale and kind: The commitment must be proportionate to the nature and impact of the development.
These tests apply to unilateral undertakings as well as conventional Section 106 agreements.
For example, a developer proposing a small residential scheme may be asked to contribute towards a local infrastructure improvement. The authority must be able to demonstrate why the contribution is necessary, how it relates to the development and why the amount is proportionate.
An undertaking that offers an excessive contribution or attempts to address an unrelated local issue may not satisfy these requirements.
Getting this assessment right is important because an undertaking should resolve a legitimate planning concern rather than become an unnecessary financial or legal burden on the developer.
Legal Requirements for Preparing an Effective Unilateral Undertaking
Although a unilateral undertaking may be more straightforward to prepare than a negotiated Section 106 agreement in suitable circumstances, it remains a formal legal instrument. Poor drafting can undermine its intended planning benefit or create obligations that become difficult to manage after execution.
Several legal and practical considerations should therefore be addressed before the document is signed.
Identifying Everyone With a Relevant Interest in the Land
The person signing the undertaking must have the appropriate legal interest in the land and can only bind their own interest and successors in title to that interest.
Where a property has multiple owners, leaseholders, mortgagees or other relevant interests, the ownership position must be investigated carefully.
It may be necessary for all relevant parties to execute the document to ensure that the intended obligations are properly secured.
Defining the Obligations Clearly
The undertaking should explain precisely what the signatory is agreeing to do, restrict or pay.
For financial contributions, this includes identifying the amount, purpose and circumstances in which payment becomes due.
Where the obligation relates to a specific part of the site, the relevant land should be clearly identified, using an appropriate plan where necessary.
Setting Out the Correct Trigger Events
An undertaking should establish when each commitment takes effect.
For example, a financial contribution might become payable before development commences, following the occupation of a specified number of homes or at another clearly defined stage.
Unclear trigger provisions can create disputes and make it difficult for the local planning authority to enforce the obligation.
Ensuring the Undertaking Does Not Bind Non-Signatories
A unilateral undertaking should not attempt to impose obligations on people or organisations that have not signed it.
For example, the document should not attempt to require a registered provider to exchange contracts within a particular period if that provider is not a party to the undertaking.
This is an important consideration when structuring commitments involving third parties, particularly where a development depends on arrangements with housing providers or other external organisations.
Using a Unilateral Undertaking During a Planning Appeal
A unilateral undertaking can be particularly valuable when a developer is challenging a planning refusal or appealing against a local authority’s failure to determine an application.
In some cases, the planning authority may have identified concerns that could potentially be resolved through a planning obligation but may not be willing to enter into an agreement with the applicant.
The developer can consider submitting a unilateral undertaking to demonstrate a willingness to address those concerns through legally enforceable commitments.
For instance, where a development has been refused partly because of concerns about its impact on local infrastructure, an appropriately drafted undertaking may offer a financial contribution towards the necessary mitigation.
The planning inspector will still need to assess whether the proposed obligation is relevant, necessary and compliant with the applicable planning tests.
The document should therefore be prepared as part of the wider appeal strategy rather than treated as an afterthought. It must clearly explain how the proposed commitment addresses the planning issues being considered.
What Happens After a Unilateral Undertaking Has Been Signed?
Once properly executed as a deed, a unilateral undertaking creates legally binding obligations.
Planning obligations generally run with the land and can be enforced against successors in title, subject to the applicable legal provisions.
This means that the consequences of signing the document may extend beyond the original developer. Future owners can inherit obligations attached to the property, making it important to understand the long-term implications before execution.
Another important consideration is that a unilateral undertaking cannot normally be withdrawn or amended simply because the original signatory changes their mind.
Under Section 106A of the Town and Country Planning Act 1990, an application may be made to modify or discharge a planning obligation. For obligations entered into after 6 April 2010, this route is generally available after five years from the date the obligation was entered into. There may also be scope for voluntary modification or discharge by agreement with the local planning authority.
This makes careful drafting particularly important. The developer should consider not only the immediate planning application but also the effect of the undertaking on future ownership, occupation and development of the land.
Professional Advice on Unilateral Undertakings and Planning Obligations
A unilateral undertaking can be an effective way to secure developer commitments and address planning concerns without the full negotiation process associated with a conventional Section 106 agreement.
However, its usefulness depends on selecting the right obligations, establishing the ownership position and ensuring that the document is legally precise and proportionate.
For developers, landowners and property professionals, obtaining specialist advice before signing an undertaking can help avoid unnecessary financial commitments, drafting errors and complications during a planning appeal.
At Charrette Law, we understand that planning obligations can have significant implications for development costs, project timelines and future land ownership. We assist clients with planning-related legal matters, helping them assess their obligations and consider appropriate strategies for addressing planning difficulties.
Whether you are preparing a planning application, responding to a planning refusal or considering a unilateral undertaking as part of an appeal, professional guidance can help protect your interests and support a more effective planning strategy.
Contact Charrette Law to discuss your planning obligations and the legal considerations affecting your proposed development.
Frequently Asked Questions About Unilateral Undertakings
What Is the Main Difference Between a Unilateral Undertaking and a Section 106 Agreement?
A unilateral undertaking is executed by the person or persons giving the planning obligations without the local planning authority becoming a signatory. A Section 106 agreement is entered into by the relevant parties, usually including the developer and local planning authority.
Can a Unilateral Undertaking Help With a Refused Planning Application?
Yes. It can be submitted during a planning appeal to address specific concerns through legally binding commitments. However, the inspector must still assess whether the undertaking satisfies the relevant planning tests.
Does a Unilateral Undertaking Have to Be Registered Against the Property?
Planning obligations generally bind the land and successors in title. The appropriate registration requirements and arrangements should be considered as part of preparing and executing the deed.
Can a Developer Change a Unilateral Undertaking After Signing It?
It cannot normally be changed or withdrawn unilaterally after execution. Modification or discharge may be possible through agreement with the local planning authority or an application under Section 106A, subject to the applicable requirements.
Does a Unilateral Undertaking Always Speed Up Planning Permission?
No. It can reduce negotiation where the obligations are straightforward and only the developer needs to be bound. However, the authority or planning inspector must still assess its legal validity and planning relevance.
Who Should Prepare a Unilateral Undertaking?
A solicitor or suitably experienced legal professional should assist with preparing and reviewing the document. The land ownership position, proposed obligations, execution requirements and enforcement provisions must all be addressed correctly.
