Can I stop a neighbour's extension blocking my light?
Sometimes — but only if you've actually acquired a legal right to light, and it's separate from planning permission. A right to light is an easement attached to a particular window or opening, most often acquired under section 3 of the Prescription Act 1832 by 20 years' uninterrupted enjoyment of light through it without written consent. The test is loss of adequate light, not all light, measured by surveyors using the Waldram method. Crucially, it's independent of planning law: an extension can have full planning permission and still infringe your right, and passing the council's 45-degree rule doesn't guarantee compliance. A neighbour or developer can block a right from arising by serving a Light Obstruction Notice under the Rights of Light Act 1959. Remedies are an injunction or damages. In short: yes, if you have an established right — but expect a technical, valuation-driven dispute.
📋 The rules
- A right to light is an easement on a specific window
- Usually acquired by 20 years' uninterrupted enjoyment
- Test is loss of adequate light, not all light
- It's separate from planning permission
- Remedy is an injunction or damages
🔓 Exceptions
- Written consent or an interruption can defeat a prescriptive right
- Windows under 20 years old usually have no acquired right
- Scotland uses servitudes; the 1959 Act doesn't apply there
⚠️ Penalties & fines
This is a civil matter — there are no fines. If a court finds your right to light is infringed, it can grant an injunction (stopping or requiring alteration of the building) or award damages in lieu. Damages may reflect the diminution in your property's value or, increasingly for large completed schemes, a "negotiating" sum representing a share of the developer's profit — anything from thousands to hundreds of thousands of pounds. You need 20 years' enjoyment for a prescriptive right, and a Light Obstruction Notice can break that run before it matures. Beware a myth: "if the extension got planning permission, it can't be unlawfully blocking my light" is false — planning and right to light are entirely separate; and not everyone automatically "has a right to light" — you only do if you acquired one. If you're worried about a neighbour's build: get a right-to-light surveyor's assessment early, before the structure goes up.
📎 Official sources
- GOV.UK — practice guide 62a: rights to light or air →
- Prescription Act 1832 →
- Rights of Light Act 1959 →
❓ Frequently asked
Do I automatically have a right to light?
No. A right to light isn't automatic — it's a legal easement attached to a specific window or opening. Most commonly it's acquired under the Prescription Act 1832 after 20 years of uninterrupted enjoyment of light through that window without written consent. If your window is newer than that, you may have no established right to protect.
Can I object even if the extension has planning permission?
Yes. Right to light is completely separate from planning law. A neighbour's extension can have full planning permission and still unlawfully interfere with your acquired right to light. Equally, the council's 45-degree daylight guideline being met doesn't guarantee your right to light is protected — they're judged by different legal and technical tests.
How is loss of light measured?
Surveyors assess whether you're left with adequate light, not whether you've lost some light. The standard approach is the Waldram method, which measures how much of a room still receives sufficient natural light. If an extension reduces the well-lit area below accepted benchmarks, that can amount to an actionable loss of light.
What can I do about it?
If you have an established right, you can seek an injunction to stop or alter the building, or claim damages. Courts increasingly award damages rather than ordering large finished buildings to be changed. It's wise to instruct a right-to-light surveyor early, ideally before construction, as acting before the structure is built strengthens your position.
Can a neighbour stop me gaining a right to light?
Yes. A neighbour or developer can prevent a right to light maturing by serving a Light Obstruction Notice under the Rights of Light Act 1959, which is registered as a notional obstruction and interrupts your 20-year period. This is a common way for landowners to stop neighbouring windows acquiring rights over their development land.
🔎 Common searches
What people search to land here:
- “right to light uk explained”
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- “prescription act 1832 light”
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