A right to light surveyor is a specialist RICS-chartered surveyor who advises on the legal right to receive natural light through windows - an easement that can be acquired by long use and enforced by court injunction or damages. They use the Waldram diagram method and BRE daylight and sunlight guidelines to quantify the impact of proposed development on neighbouring properties, and advise developers, neighbours and solicitors on the risk of infringement, mitigation options and the quantum of any compensation payable.
What they do
- Carry out preliminary right to light assessments for proposed development
- Produce Waldram diagram analyses to quantify light loss
- Produce BRE daylight and sunlight impact studies
- Advise developers on design modifications to avoid infringement
- Negotiate financial settlements on behalf of affected neighbouring owners
- Advise on right to light insurance and risk management strategies
- Produce expert witness reports for litigation and adjudication
- Advise on the registration of light obstruction notices
- Assess whether a right to light has been acquired or extinguished
When you need one
A right to light surveyor should be consulted before any development that could affect natural light to neighbouring windows - and by neighbours whose light is threatened.
Typical costs (UK, 2025)
| Job type | Typical cost |
|---|---|
| Preliminary right to light assessment | £800 - £2,000 |
| Full right to light report | £1,500 - £5,000 |
| Daylight and sunlight study (BRE guidelines) | £1,000 - £4,000 |
| Expert witness report | £1,000 - £3,500 |
| Negotiation and settlement support | £800 - £2,500 |
| Hourly rate | £90 - £160 / hr |
Costs depend on the complexity and number of affected windows. Urban schemes with many neighbouring properties will require more extensive analysis. Expert witness and litigation support attracts premium rates.
Qualifications to look for
Right to light surveyors are typically RICS-chartered building surveyors or general practice surveyors with specialist experience in rights to light, daylight and sunlight assessment. Check membership at rics.org.
Where the surveyor is acting as an expert witness in litigation or adjudication, membership of the EWI or AoE demonstrates knowledge of expert witness duties under CPR Part 35.
Frequently asked questions
What is a right to light?
A right to light is a legal right (an easement) that entitles the owner of a building to receive natural light through defined windows. A right to light is acquired after 20 years of uninterrupted use of natural light. It is a property right that can be enforced by injunction or damages in court.
How much light reduction is actionable?
The law uses the 45-degree rule and the Waldram method to assess whether sufficient natural light remains for comfortable use of a room without artificial lighting. A reduction to less than 0.5% average daylight factor in 50% of a room is typically actionable.
What can a developer do if their scheme infringes a right to light?
Options include: negotiate a financial settlement (payment to the affected owner), modify the design to avoid infringement, obtain a release of the right, or take out right to light insurance. Each approach has different cost and risk implications and a specialist surveyor can advise on the most appropriate course.