Rights of light or planning daylight: which risk is which
A private right to light and the planning daylight assessment use different measurements, different decision makers and different remedies. Permission is no defence to an injunction.
Planning permission does not give you a right to block someone's light, and a right to light does not stop a council granting permission. Rights of light are a private property matter enforceable in the courts, while planning daylight and sunlight is a public interest judgement made by the local planning authority against BRE guidance. A scheme can pass the planning test and still face an injunction from next door, which is why the two risks belong on separate lines of the appraisal.
The confusion is understandable, because both use sky, windows and numbers. The measurements, the thresholds, the decision maker and the remedy are all different.
The civil right and how it arises
A right to light is an easement. It attaches to a defined aperture, a window or a rooflight, rather than to a garden, a wall or an open plot. The usual route to acquiring one is 20 years of uninterrupted enjoyment under the Prescription Act 1832, and it can also arise by express grant or by reservation in a deed.
Once acquired, the right protects a quantity of light sufficient for the ordinary use of the room. The traditional yardstick used by surveyors is the Waldram approach, which asks how much of a working plane at table height receives a defined sky factor. A room that keeps around half of its area adequately lit is conventionally treated as having enough. Reduce it below that and the owner has a claim.
None of that appears in the development plan. The right exists whether or not a planning application is ever made.
What the planning assessment measures
The planning test looks outward at the effect of a proposal on the amenity of existing occupiers and at the quality of daylight inside the new units. Officers work from BRE 209, Site Layout Planning for Daylight and Sunlight, whose third edition was published in 2022 and moved the recommended method towards target illuminance and the criteria in BS EN 17037.
The familiar numbers still appear in most reports: the vertical sky component measured at the centre of a neighbouring window, with 27 per cent as the reference value, and the retained proportion of the former value where the reference is not met. Sunlight to windows is tested through annual and winter probable sunlight hours, and sunlight to gardens and amenity space through a separate sun on ground exercise. A Daylight and Sunlight Assessment sets those results against the guidance, and an Overshadowing Study deals with the ground plane.
BRE 209 describes itself as guidance, not as a standard to be applied rigidly, and says the numbers should be applied flexibly in dense urban areas. Officers know this. So a breach of a numeric target is a material consideration to be weighed, and on a city centre site it is regularly outweighed by other benefits.
Why a consented scheme can still be injuncted
The decision makers are different, and neither binds the other. A local planning authority has no power to extinguish a private easement by granting permission, and the county court or High Court does not sit to review the planning judgement.
| Rights of light | Planning daylight and sunlight | |
|---|---|---|
| Source | Prescription Act 1832, express grant, deeds | BRE 209, development plan amenity policies |
| Decided by | The courts | The local planning authority, then the Planning Inspectorate on appeal |
| Protects | A specific aperture with 20 years of enjoyment | Amenity of occupiers generally, and internal daylight in new homes |
| Remedy | Injunction or damages | Refusal, conditions, or design changes |
| Time limit | No planning deadline, claim brought when interference occurs | Within the determination period, or on appeal |
The practical consequence is sequencing. Permission is a gateway, not an immunity. Courts have been willing in principle to grant a mandatory injunction requiring a completed part of a building to be cut back, which makes the neighbour's bargaining position far stronger than a damages claim alone would.
One statutory escape route exists for public sector land. Section 203 of the Housing and Planning Act 2016 lets a qualifying authority, and anyone deriving title from it, override an easement where the land has been appropriated or acquired for planning purposes. The neighbour is then left with compensation rather than an injunction. Deals on regeneration sites are frequently structured around it.
Remedies and who holds the stronger hand
On the civil side the neighbour can seek an injunction, either to stop construction or to require cutting back, or accept damages. Damages may be assessed on a book value basis derived from the loss of light, or on a release fee basis reflecting a share of the developer's profit, which tends to produce much larger figures.
On the planning side the authority can refuse, impose conditions, or negotiate a revised massing. There is no compensation. A refusal on amenity grounds can be appealed, and a section 73 or section 96A route is often how a consented scheme is adjusted once a rights of light surveyor has run the numbers on the approved drawings.
Insurance and release negotiations
Rights of light insurance is a normal part of a development appraisal. Policies typically respond to the cost of an injunction and the cost of settlement, and insurers will look closely at whether the developer has approached neighbours, because contact can itself prejudice cover. Read the policy wording before writing to anyone.
Releases are the alternative. A deed of release from each benefiting owner removes the risk at a price, and on a terrace of affected flats that price is a function of how many owners hold out. Identifying the correct legal owners early matters, and it overlaps with the ownership certificates A, B, C and D exercise you are already doing for the planning application.
A light obstruction notice under the Rights of Light Act 1959 works the other way. It lets a landowner register a notional obstruction with the local authority to interrupt a neighbour's 20 year accrual before the right matures, which is a defensive tool for someone with a site they intend to develop later.
Sequencing the surveys and the notices
- Commission a desk based rights of light appraisal at the massing stage, before the design is fixed, using measured survey information for neighbouring windows where it can be obtained.
- Run the BRE 209 assessment in parallel for the planning submission, covering both neighbouring amenity and internal daylight to the proposed units.
- Put insurance in place before any approach to a neighbour.
- Take the legal title work in step with the planning ownership certificates.
- Revisit the rights of light numbers after any design change made to satisfy the planning officer, because a change that improves the planning position can worsen the civil one.
That last point catches people out. Pushing massing away from one boundary to fix a vertical sky component breach can deepen an interference with a protected aperture on the other side.
Running both risks together
Treat them as two tests with one design. The planning assessment drives the application and the officer report. The civil appraisal drives the appraisal, the insurance premium and, on constrained sites, whether the top two floors are worth building at all.
Where budget is tight, the honest advice is that the civil risk deserves the earlier spend. A planning refusal on daylight can usually be answered by redesign and resubmission. An injunction after practical completion cannot.
PlanScope can produce the AI-assisted daylight, sunlight and amenity documents that sit in the planning submission, structured to UK planning policy and with missing site data flagged rather than assumed. Councils expect a suitably qualified author for this work and professional review is strongly advised, and rights of light advice is a separate instruction to a specialist surveyor or solicitor.
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
Does planning permission override a neighbour's right to light?
No. A local planning authority has no power to extinguish a private easement, so a permission leaves the civil claim untouched. The only common exception is land held by a qualifying public authority, where section 203 of the Housing and Planning Act 2016 can override the easement and replace it with a right to compensation. Take legal advice on whether that applies.
How long does it take to acquire a right to light?
Twenty years of uninterrupted enjoyment through a defined aperture under the Prescription Act 1832, unless the right was granted expressly in a deed. A new window therefore has no protected right for two decades. A landowner who wants to stop the clock can register a light obstruction notice under the Rights of Light Act 1959 before the period matures.
What is the 27 per cent figure in daylight reports?
It is the vertical sky component reference value in BRE 209, measured at the centre of a neighbouring window. Below it, the guidance looks at whether the retained value is at least 0.8 times the former figure. BRE describes these as guidance to be applied flexibly, particularly in dense urban areas, rather than as pass or fail standards.
Do I need both a rights of light appraisal and a planning daylight assessment?
On a constrained urban site, yes. They answer different questions for different audiences and neither substitutes for the other. The planning assessment goes into the application. The rights of light appraisal informs the development appraisal, the insurance position and any negotiation with neighbouring owners, and is normally commissioned earlier.
Can a court order a completed building to be cut back?
It is possible. Courts retain the discretion to grant a mandatory injunction rather than award damages, and that possibility is what gives an affected owner real bargaining power in settlement talks. Damages may instead be assessed by reference to a share of the developer's profit, which usually exceeds a simple valuation of the lost light.
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.