What happens if I start work without serving notice?

We regularly get calls from homeowners whose builder has already started, sometimes with the steel already in. The position is recoverable, but it is better to understand the risk before it happens.

What the Act actually says

The duty to serve notice is a precondition of the rights the Act gives. Section 3(1) says that before exercising any section 2 right, a building owner “shall serve” a party structure notice. Section 6(5) requires a section 6 notice “at least one month before beginning to excavate”. Section 1 has similar timing for new walls. The Act does not create an offence for failing to serve notice; the offences in section 16 concern occupiers refusing or obstructing lawful entry. The consequences are civil.

The consequences in practice

• Injunction. The courts treat the Act as giving a building owner rights in exchange for following its procedures. A neighbour can seek an injunction to stop work until notice is served and the statutory procedure followed. Injunctions are a costly, stressful and avoidable delay.
• No statutory protection for you. Without notice, you cannot rely on the Act to justify what you have done. Cutting into or building on the neighbour’s side of a party wall is often described as “no notice, no Act”: you are in a worse position because you have not followed the due process set out in the Act of Parliament that specifically covers notifiable works, losing its protections and dispute-resolution route and risking an injunction or damages.
• Damage liability. You still have to compensate for loss or damage (section 7(2)). Without a Schedule of Condition, it is hard to show what damage was already there, so you may end up paying for pre-existing defects.
• Costs. Retrospective awards, opening-up to inspect hidden work, and the neighbour’s surveyor’s reasonable fees (s.10(13)) can all fall on you.
• Insurance and sale. Missing paperwork can be raised by a buyer’s solicitor when you sell. See selling during party wall works.
• Relationships. Neighbours who discover work being done without notice are far more likely to dissent, appoint their own surveyor and scrutinise everything.

Can surveyors make a retrospective Award?

Surveyors’ jurisdiction comes from a valid notice and a dispute under section 10. Where work has started, the usual course is to serve notice for the remaining and continuing notifiable work, then have the surveyors deal with the rest of the job. Surveyors can then make an Award covering how the remaining work is done, and often they will address damage already caused if both sides agree to it. The extent of their power over work completed before notice is a matter on which surveyors take a cautious view, and where it is contested, damage for completed work may have to be pursued through the courts rather than the Award. That uncertainty is a good reason to serve notice first.

If you have already started: what to do

1. Stop the notifiable parts of the work. Non-notifiable work elsewhere can usually continue. Make the site safe; do not leave a wall unsupported.
2. Talk to your neighbour straight away. Explain what has happened and that you are putting it right.
3. Serve the correct notices for all notifiable work, describing what has already been done and what remains. Ask the neighbour for consent to an earlier start (section 3(3)(a)).
4. Offer a Schedule of Condition of their property now, before more work is done.
5. If there is a dispute, get surveyors appointed quickly so an Award can be made for the remaining work.
6. Deal promptly with any damage, either by making good or by paying the cost.

Builders and “it’s on our side”

The most common reason we see for starting without notice is a builder saying the work is “all on your side”. That is not the test. Removing a chimney breast, cutting a beam pocket, or digging foundations within 3 m and below the neighbour’s footings are notifiable regardless of which side of the boundary the work is on. Build the notice period into the programme from the start: two months for section 3, one month for sections 1 and 6. See notice periods.

Prevention checklist

• Ask your architect or designer to flag party wall items when drawings are done.
• Serve notices as soon as the design is fixed, even before planning or building control approval.
• Write the notice periods into your building contract and programme.
• Tell your builder in writing not to start notifiable work until consent or an Award is in place.
• Arrange Schedules of Condition before the builder arrives.

Worked example (illustrative)

Illustrative only. Not a real case.

A builder starts a rear extension and digs foundations along the boundary within 2 m of the neighbour’s kitchen, below its footings, without a section 6 notice. The neighbour notices cracks and calls a surveyor, who writes threatening an injunction. The building owner stops the foundation work, serves section 6 notices for the remaining excavation and agrees to an earlier start. Both sides appoint surveyors. A Schedule of Condition is taken of the neighbour’s kitchen as it is now; the surveyors agree the remaining foundation method and the cost of repairing the cracks caused so far, which the building owner pays. The project resumes about six weeks later than planned, with higher fees than if notice had been served at the outset.

At a glance

What the neighbour’s surveyor will usually ask for

When notice is served late, the adjoining owner’s surveyor will be more cautious than usual, because some work is already hidden. Expect requests for:

• Opening up. Exposing a beam bearing, padstone or foundation so its size and position can be checked against the engineer’s design.
• Engineer’s confirmation that what has been built matches the design and that the party wall is adequately supported.
• Photographs and records from your builder of the work done so far.
• A Schedule of Condition taken now, with any damage already visible identified separately.
• Building control records of inspections carried out.

The reasonable cost of this extra investigation normally falls on the building owner under section 10(13). Cooperating fully and promptly is the quickest way back on site.

Can the neighbour claim more than repair costs?

Where work has caused loss, section 7(2) covers loss or damage resulting from work executed in pursuance of the Act. For work done outside the Act, claims lie in ordinary law, and a court may award damages and costs. Either way, an early, fair offer to put things right usually costs far less than litigation.

Remember too that not every trade near the wall is notifiable: minor chases for sockets and wiring are not, and nor are rooflights where nothing goes into the party wall. The risk lies in section 1, 2 and 6 work.

Sources and further reading

• Party Wall etc. Act 1996, section 1: New building on line of junction (legislation.gov.uk)
• Party Wall etc. Act 1996, section 3: Party structure notices (legislation.gov.uk)
• Party Wall etc. Act 1996, section 6: Adjacent excavation and construction (legislation.gov.uk)
• Party Wall etc. Act 1996, section 7: Compensation etc. (legislation.gov.uk)
• Party Wall etc. Act 1996, section 10: Resolution of disputes (legislation.gov.uk)
• Party Wall etc. Act 1996, section 16: Offences (legislation.gov.uk)
• The Party Wall etc. Act 1996: explanatory booklet (GOV.UK)

This guide is general information on the law in England and Wales, written from our surveyors’ practical experience. It is not legal advice; for a specific dispute, take advice on your own facts.

Sources: Party Wall etc. Act 1996 (legislation.gov.uk) · The Party Wall etc. Act 1996: explanatory booklet (GOV.UK). Last reviewed 27 October 2026. General guidance on the law in England and Wales, not legal advice.