What is the Party Wall Act? The Party Wall etc. Act 1996 governs three situations: work to a shared wall or structure (cutting in loft beams, removing chimney breasts, raising or rebuilding); new walls at or astride a boundary; and excavation within 3 metres of a neighbour's structure below their foundation level (6 metres for defined deeper cases — basements, piling). Building owners must serve written notice before starting; the process that follows produces a condition record and, where needed, a formal award governing the works.
Does your project trigger it?
| Project | Act engaged? | Which provision |
|---|---|---|
| Loft conversion (beams into party wall) | Almost always | Party structure — 2 months' notice |
| Rear/side extension near boundary | Usually | Excavation 3m rule — 1 month; boundary wall provisions |
| Basement / underpinning | Yes | Excavation 3m/6m rules; party structure where underpinning shared walls |
| Chimney breast removal (party wall) | Yes | Party structure — 2 months |
| Internal works not touching shared structure | No | — |
The process for building owners
- Serve notice early — 2 months ahead (party structure) or 1 month (excavation/boundary); correct form, correct owners (all of them, including leaseholders and freeholders next door)
- Await response — written consent lets work proceed (record condition anyway); dissent or 14 days' silence triggers the surveyor route — normal, not hostile
- The award — appointed surveyor(s) record a schedule of condition and issue an award: how, when, safeguards, access, making good
- Build under it — then close out against the schedule on completion
Programme truth: notices served late delay more London projects than weather. Serve with the planning application, not with the skip order.
Receiving a notice: your position
You have three responses: consent (fast, but insist on a condition record); dissent and appoint the agreed surveyor jointly (impartial, economical, suits straightforward works); or dissent and appoint your own surveyor (the building owner normally pays reasonable fees). You cannot veto lawful work — the Act enables it — but you're entitled to the protections: proper notice, condition schedule, an award with safeguards, and its damage-resolution mechanism if cracks appear. For basements especially, take advice from an independent structural engineer — ideally IStructE or ICE chartered — before responding; consenting blind to deep excavation next door surrenders your best evidence.
Costs, damage and disputes
Typical London awards run £700–£1,500 per adjoining owner for standard works (building owner pays), multiples more for basements. Damage during works resolves through the award: compared against the schedule of condition, made good or compensated — which is precisely why the schedule matters more than any other document. Without the Act followed, both sides lose: owners face injunctions and unprotected liability; neighbours face damage disputes with no baseline evidence. The Act is that rare thing — bureaucracy that genuinely serves everyone who uses it properly.
This guide provides general information only and is not formal structural advice for any specific property. The cause of movement or damage should always be established by proper professional assessment before repairs are commissioned.