Planning permission is not a defence to damaging the house next door

Two permissions people confuse

When a neighbour begins building, the first question asked is usually whether they have permission. It is a reasonable question and it answers less than people expect, because approval from a planning or building authority is a decision about the public interest in development: land use, appearance, safety, sometimes amenity. It is not a licence to interfere with rights belonging to somebody else.

Private rights sit on a separate track entirely. A right of light, a right of way, a restrictive covenant limiting what may be built, and the general obligation not to damage a neighbour’s property all exist independently of the planning system. A development that is fully approved may still be actionable by a neighbour, and a development that was never approved may cause a neighbour no legal harm at all.

Works to a shared or adjoining structure

Building against, on, or close to a boundary raises problems that ordinary construction does not, because the work touches something the neighbour has an interest in. Many jurisdictions have therefore created a specific procedure for it, requiring the building owner to notify adjoining owners before starting, to describe the works, and to allow a period in which the neighbour may consent or dissent.

The details vary enormously and some places have no such regime at all, relying instead on general property and negligence rules. Where a procedure exists, its usual features are a record of the condition of the adjoining property before work begins, an independent determination of disputes about how the works should be carried out, and an obligation on the building owner to make good damage. That condition record is the single most valuable document in any later argument.

Temporary disturbance and permanent harm are different complaints

Construction is noisy, dusty and disruptive, and legal systems generally accept that some disturbance is an unavoidable feature of living near other people. What is normally required is that the work be carried out reasonably: at sensible hours, with proper precautions, and without prolonging the disturbance unnecessarily. Reasonable inconvenience is usually tolerated. Unreasonable methods are not.

Physical damage is a different matter. Cracking caused by excavation, water ingress after a roof is opened up, or the undermining of a foundation is harm rather than inconvenience, and it engages obligations that do not depend on whether the work was permitted. Some categories of especially hazardous work attract stricter responsibility in many systems, so that the party carrying it out answers for the damage even without proof of carelessness.

Who is actually responsible

The neighbour building the extension is the obvious target, and often the right one, but not always the only one. A contractor may be liable for its own negligence, a designer for a defective design, and in some circumstances a property owner cannot escape responsibility by pointing at the firm they hired, particularly where the work was inherently likely to cause harm.

Insurance decides much of what happens next in practice. Contractors normally carry cover for damage to third-party property, and a claim routed through that policy is generally quicker than litigation. Which is why the useful early question is not who is to blame but who is insured, and why photographing the state of a property before neighbouring works begin is worth the twenty minutes it takes.

Access, scaffolding and the right to say no

Building work often requires access over the neighbour’s land, and the neighbour is generally entitled to refuse it. Some jurisdictions have created a limited procedure allowing a court to authorise access for necessary preservation works on conditions, precisely because an absolute veto could leave a building unrepairable. Where no such procedure exists, access is a matter for negotiation.

A neighbour asked for access is usually in a stronger position than they realise, and using that position aggressively is a poor strategy. Reasonable conditions about timing, insurance, making good and a condition record protect the neighbour without provoking the escalation that turns a fortnight of scaffolding into a multi-year dispute between people who continue to live next to each other.

Where the local rules take over

Whether a formal procedure applies to works near a boundary, what rights of light or support exist, how far strict responsibility reaches, and what access can be compelled are all matters of local law with genuinely different answers between countries and regions. Nothing here describes any particular building or dispute, and the outcome depends on surveys, titles and construction records that a general article cannot see.

The practical warnings are consistent, though. Do not interfere with a neighbour’s works, remove supports, or carry out counter-works of your own, all of which can convert a claim into a liability. Record the condition of the property before work begins and as damage appears. And where damage has occurred, take advice from a qualified lawyer or surveyor early, because claims of this kind are subject to time limits that continue to run while correspondence goes back and forth.