"A right to light is a legal easement that allows property owners to enjoy natural light passing over neighbouring land and into defined apertures such as windows, skylights and glass roofs into a building"
- Mustafa Sidki - Thackray Williams
The relaxation of planning laws in December 2024 is expected to drive disputes over ‘right-to-light,’ particularly in urban areas like London, where space is at a premium. With developers increasingly building upwards to address housing shortages, conflicts with neighbouring property owners over access to natural light are on the rise.
The impact of these planning reforms on building up
The government’s latest reforms aim to deliver 1.5 million new homes by 2030, tasking local councils with annual housing targets of 370,000 homes. Urban areas with severe housing shortages and high unaffordability are under the most pressure. The reforms encourage “airspace developments,” allowing landlords and developers to extend upwards into the airspace above existing buildings.
While modular construction makes these upward extensions efficient, experts are predicting an increase in disputes with neighbouring property owners over who holds rights to light.
What is right to light?
A right to light is a legal easement that allows property owners to enjoy natural light passing over neighbouring land and into defined apertures such as windows, skylights and glass roofs into a building. The Prescription Act of 1832 establishes these rights after 20 years of uninterrupted light access.
Once established, the right ensures sufficient light to use the affected room for its intended purpose—for example, a living room or workspace requires more light than a storage area.
How is right to light measured?
To claim a right to light infringement, the reduction in light must constitute a material nuisance. This means the affected property must be substantially less comfortable or practical to use.
Light is assessed using the ‘sky factor,’ which measures the percentage of visible sky from a specific point. A room is typically considered adequately lit if 0.2% of the sky factor illuminates at least half the room’s floor area at working plane height (e.g., table level).
If a new development reduces light below this threshold or significantly worsens conditions in already substandard spaces, a potential claim for infringement of the right of light may well arise.
Legal recourses for right to light infringements
Planning permission does not override a neighbouring property’s right to light. Property owners can take legal action to protect their rights through:
1. Prohibitory Injunctions: At any time before the development is completed seeking an order to prevent the development
2. Mandatory Injunctions: After the development is completed seeking an order that the development be demolished or cut back to prevent interference with the right of light
Courts often favour financial damages over injunctions if compensation is deemed adequate. However, severe infringements may result in injunctions, with courts sometimes going as far as to order the demolition of completed buildings.
Damages are calculated based on:
· Property value reduction: Compensation for the financial impact of diminished light
· Developer’s gains: A share of the profits the developer stands to make from the project
How to proactively manage right-to-light risks
To avoid disputes, the following steps should be taken early in the planning process:
1. Commission a right-to-light report
This is a technical report that identifies affected properties, quantifies potential light loss and suggests mitigation strategies. Local councils often require these reports as part of planning applications in urban areas.
2. Negotiate agreements with neighbours
If neighbouring properties are affected, developers can negotiate a ‘deed of release’ which waives or modifies the right to light. These agreements must be formalised and registered with HM Land Registry.
3. Design modifications
Adjusting building designs, such as setting back upper floors, can help reduce light obstruction and avoid disputes entirely.
Using light obstruction notices as a strategic tool
Under the Rights of Light Act 1959, developers can issue a “light obstruction notice” to interrupt a neighbouring property’s right to light. This notice creates a hypothetical barrier and gives affected parties one year to object.
If no objection is raised, the right to light is considered interrupted, resetting the 20-year acquisition period. Light obstruction notices are particularly useful for:
· Preventing new rights from being established
· Identifying potential disputes early in the process
Right-to-light insurance
Developers can also secure indemnity insurance to cover legal claims and compensation costs. However, generally, insurance will not be available if negotiations have started with the owners or occupiers of the surrounding buildings. So a property owner often has to choose between:
· Taking indemnity insurance against a possible claim for infringement of a right of light
· Negotiating the release of the right of light
Right-of-light indemnity insurance usually lasts in perpetuity and benefits successors in title, but it is prudent to check the terms of the policy. There may also be an excess to pay that should be taken into account.
Taking advice from a specialist right-to-light surveyor and a specialist lawyer is crucial, especially given the more flexible approach to planning permission arising from the government’s reforms.
