Why Developers Use Light Obstruction Notices: Protecting Future Schemes

When planning and delivering new developments, one of the most persistent risks for developers and architects in England and Wales is a rights to light claim. These claims can delay schemes, reduce development potential, or result in costly compensation payments. A powerful legal tool exists to help mitigate this risk: the Light Obstruction Notice (LON).

In this article, we explain why developers use a Light Obstruction Notice, how it works under the law, and how it can protect the future of your scheme.

Understanding Rights to Light

Under the Prescription Act 1832, a property can acquire a legal right to light if it has enjoyed uninterrupted daylight through a window or other aperture for at least 20 years. Once established, this right allows the property owner to object to any neighbouring development that substantially reduces the amount of light they receive.

For developers, this means that even if you obtain planning permission, neighbouring owners could still bring a private legal claim if your building interferes with their light. Such claims can lead to:

Injunctions halting development or requiring demolition of completed structures.

Compensation payments, sometimes amounting to a significant share of the scheme’s uplift in value.

Delays while negotiations or litigation are resolved.

What Is a Light Obstruction Notice?

The Rights of Light Act 1959 introduced the concept of a Light Obstruction Notice. Rather than physically constructing an obstruction to interrupt light, a landowner can apply to register a notional obstruction - a legal fiction recorded in the local land charges register.

Once registered, the LON has the same effect as if a physical wall had been built in the location and dimensions specified. This prevents a neighbouring property from completing the 20 years of uninterrupted use required under the Prescription Act.

In short, a Light Obstruction Notice is a preventive tool: it stops new rights of light from being acquired by neighbouring properties.

Why Developers Use a Light Obstruction Notice

1. Protecting Future Development Potential

Developers often assemble sites with long-term visions - phased regeneration, tall buildings, or intensification of urban plots. If neighbouring windows quietly acquire rights to light over time, future schemes could be severely constrained.

By registering a LON, developers effectively “freeze the clock” on the acquisition of new rights to light, ensuring that their land remains developable for years to come.

2. Avoiding Costly Compensation Claims

Without a LON, neighbours can build a stronger case that they have accrued rights to light. This can translate into substantial damages claims or, in some cases, injunctions.

A properly registered Light Obstruction Notice removes this risk before it matures, reducing the chance of disputes escalating into costly legal battles.

3. Strategic Site Assembly

In city-centre and brownfield contexts, developers may not know the final form of their scheme when land is first acquired. Using a LON across the boundaries of a site keeps options open and prevents unexpected rights to light issues from arising later.

This flexibility is critical when schemes may evolve in response to planning negotiations, market shifts, or joint ventures.

4. Providing Certainty to Funders and Partners

Funders, joint venture partners, and institutional investors are often concerned about rights to light risks. A site with a registered LON demonstrates that the developer has proactively managed potential liabilities.

This can smooth the way for financing, de-risking transactions, and providing confidence that the scheme can proceed without hidden rights to light constraints.

5. Avoiding the Need for Premature Construction

Before the 1959 Act, developers sometimes built token walls or screens simply to interrupt light and prevent rights from accruing. This was costly, disruptive, and often impractical.

A LON achieves the same effect - interrupting the prescriptive period - but without physical works. It is a cost-effective, paper-based solution.

How Light Obstruction Notices Work in Practice

The process is administered through the Upper Tribunal (Lands Chamber):

Application – The landowner applies for a certificate from the Tribunal. This identifies the “servient land” (the developer’s land) and the “dominant building” (the neighbouring property potentially acquiring rights).

Publicity – The Tribunal requires the applicant to notify affected parties, often through direct service and newspaper notices. This ensures transparency and gives neighbours the chance to be aware of the application.

Certificate – If the Tribunal is satisfied, it issues a certificate allowing the LON to be registered as a local land charge.

Registration – The Chief Land Registrar records the LON in the local land charges register. From this point, the notional obstruction is deemed to exist in law.

Effect – The LON interrupts the prescriptive period. Any future claim to rights to light must discount the period during which the notice was registered, effectively resetting the 20-year clock.

Temporary certificates can also be issued in urgent situations - for example, if a neighbouring property is close to completing its 20 years of light use.

Example: Safeguarding a Regeneration Scheme

Imagine a developer acquires a large brownfield site in an inner-city location. Several old warehouses next door have small windows that have been in use for 15 years.

Without action, those windows will acquire rights to light in just five years. If the developer’s scheme includes residential towers, they could face serious rights to light claims from the warehouse owners.

By registering a Light Obstruction Notice today, the developer prevents those rights from being perfected. This keeps the regeneration scheme viable, maximises density, and avoids costly negotiations down the line.

Common Mistakes When Applying for a LON

The Tribunal’s own guidance highlights recurring errors:

Outlining the wrong land – Applicants sometimes outline both servient and dominant land in their plans. Only the servient land (in red) and the actual dominant building (in blue) should be shown.

Failing to act promptly – Delays in registering notices can allow rights to mature before the process is complete.

Confusing planning permission with rights to light – Developers often assume planning consent overrides rights to light. It does not. Rights to light are private property rights and can still be enforced.

Costs and Practical Considerations

Tribunal fee – The current fee for issuing a certificate is £775, or £761 for a temporary and full certificate.

Professional input – Rights to light surveyors and legal advisors are essential to ensure the plans and applications are correct. Errors can invalidate the notice.

Timing – Developers should register LONs early in the site assembly process, well before detailed design and planning.

FAQs: Why Use a Light Obstruction Notice?

Q1. Why use a Light Obstruction Notice instead of simply building on the land?

Because it allows developers to interrupt the accrual of rights to light without committing to construction. This saves costs and keeps design options open.

Q2. How long does a Light Obstruction Notice last?

A registered notice usually remains effective for one year unless renewed. Developers can apply again if longer protection is required.

Q3. Can neighbours object to a Light Obstruction Notice?

Neighbours can challenge the registration through court proceedings, but the Tribunal itself does not handle objections. This makes early professional advice crucial.

Q4. Does a LON remove existing rights to light?

No. It only prevents new rights from accruing. If a neighbour already has 20 years of uninterrupted light use, a LON will not extinguish that right.

Q5. What happens if I don’t register a LON?

You run the risk that neighbours will acquire enforceable rights to light, potentially restricting your future scheme or exposing you to compensation claims.

Q6. Is a Light Obstruction Notice always necessary?

Not always. If your scheme is already designed and neighbouring properties clearly cannot acquire rights before development begins, a LON may not add value. However, for longer-term or phased projects, it is often an essential safeguard.

Key Takeaways

Rights to light are a private legal risk separate from planning consent.

A Light Obstruction Notice interrupts the prescriptive period and prevents new rights from being acquired.

Developers use LONs to protect development potential, avoid costly claims, reassure funders, and provide long-term flexibility.

The process involves the Upper Tribunal and Land Registry and must be handled with precision.

For urban and phased schemes, LONs are a critical part of risk management.

Conclusion

For developers and architects, the question “Why use a Light Obstruction Notice?” has a clear answer: it protects your future schemes. By taking early action, you can prevent neighbours from acquiring rights to light that could limit your design freedom, increase your costs, or even derail your project.

At Anstey Horne, our rights to light specialists have extensive experience in advising on and registering Light Obstruction Notices. Whether you are assembling a new site or safeguarding a long-term regeneration scheme, we can help you navigate the process with confidence.

Need Expert Advice on Light Obstruction Notices?

At Anstey Horne, our specialist Rights to Light surveyors have extensive experience advising developers, property owners, and legal teams across the UK. We help identify risks, negotiate solutions, and ensure your project progresses with confidence. Contact us today to discuss how we can help resolve any Rights to Light concerns.

For more information on Light Obstruction notices see the collection of articles on all aspect of this service in our blog.

For advice on rights to light direct from one of our surveyors, please call our Rights to Light Enquiry Line on 020 4534 3138.

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