Right to light, overshadowing and neighbour disputes

What the right to light actually is

When the access and use of light to and for any dwelling house, workshop, or other building shall have been actually enjoyed therewith for the full period of twenty years without interruption, the right thereto shall be deemed absolute and indefeasible, any local usage or custom to the contrary notwithstanding, unless it shall appear that the same was enjoyed by some consent or agreement expressly made or given for that purpose by deed or writing.

Three features of that, all of which matter here.

It attaches to a building. The words are “dwelling house, workshop, or other building”. In practice the right is about light arriving through defined apertures — windows — into rooms. It is not a right to sunshine over your land.

It takes twenty years. The right is acquired by long enjoyment, not by installation.

It is about adequate light for ordinary use, not about the amount of light you happen to have enjoyed. Even where a right exists, the question in a dispute is whether enough light remains, not whether any has been lost.

A solar array fails at the first hurdle. It is not a building, and it does not receive light through an aperture. Nothing about installing panels creates a protected interest in the sunlight reaching them.

What about planning?

Overshadowing of neighbouring property is a material planning consideration — authorities routinely assess whether an extension would unacceptably harm a neighbour’s light and outlook.

But two things limit how much that helps you.

The assessment is about the building, not the array. The tests authorities use concern light to habitable rooms and the sense of enclosure. Loss of generation from a solar installation is not what those tests measure.

Weight is a matter for the decision-maker. You can raise it, and you should. But an authority is not obliged to refuse an otherwise acceptable development to protect your output, and there is no policy requiring it to.

So objecting is worth doing and worth doing properly — with figures, showing what proportion of output would be lost and when. Our shading page gives modelled losses for a range of obstruction scenarios, and a specific number is far more persuasive than an assertion. Just do not plan on it succeeding.

The Rights of Light Act 1959 works the other way

Worth mentioning because the name misleads. The 1959 Act allows a landowner to register a light obstruction notice, which has the effect of a notional obstruction and prevents a neighbour acquiring a right to light by prescription.

It is a tool for preventing rights accruing over your land, not for protecting your own light. It has no application to solar panels.

Trees and hedges

The same answer, with one narrow exception.

There is no general right to light over a neighbour’s trees. You may cut back branches that overhang your boundary, to the boundary line, and the cuttings belong to your neighbour. That is a right of abatement in nuisance, and it does not extend to reducing the height of a tree on their land.

High hedges. Part 8 of the Anti-social Behaviour Act 2003 allows a complaint to the local authority about a barrier of two or more evergreen or semi-evergreen trees over two metres that adversely affects reasonable enjoyment of a domestic property. It is narrow, it is about the property rather than about panels, and it requires you to have tried to resolve it first.

Tree preservation orders and conservation areas. A protected tree cannot be lopped, topped or felled without consent, and doing so is an offence. If a tree shades your array, check its status before touching it.

What to do instead: design for it

Since the legal position is weak, the leverage is entirely in where you put the array.

Look at what could be built, not just what is there. A single-storey neighbour with a large garden and a south-facing plot is a future two-storey extension. Permitted development allows a good deal without any application at all.

Check for allocations and permissions nearby before you commit. A search of the authority’s planning register for adjoining addresses takes minutes.

Prefer resilience to optimality. Our orientation figures show that south-east or south-west costs only about 6% against due south. If moving the array to a different plane makes it immune to a plausible future obstruction, that is a good trade.

Model the realistic worst case. The shading page has modelled losses for obstructions in each direction — a tall obstruction due south costs far more than the same obstruction due east, and due north costs essentially nothing.

Talk to your neighbour before you install, not after. People are much more amenable to knowing about your array than to being told they have damaged it. It creates no legal right, but it makes the conversation about their extension a different one.

If it has already happened

Check the development is lawful. If it exceeds permitted development limits or breaches a condition, that is an enforcement matter — and it is a much stronger position than any claim about light.

Check for a restrictive covenant. A covenant restricting building on the neighbouring plot is private law and enforceable by whoever has the benefit of it. See covenants.

Reconsider the array. Optimisers or microinverters reduce the effect of partial shading on the rest of the string, and relocating some panels may recover more than a dispute would.

Be realistic about litigation. Even where a claim exists, the cost of pursuing it will exceed the value of the lost generation on any domestic system. That arithmetic is worth doing before anyone writes a letter.