Party Wall Damage: How Claims Are Assessed and Settled

A party wall damage claim is, in most cases, settled by surveyors rather than a court. Where the building owner served notice under the Party Wall etc. Act 1996, damage caused to the neighbouring property is dealt with inside the Act: section 7(2) obliges the building owner to compensate the adjoining owner and occupier for loss or damage resulting from the works, and the appointed surveyors decide whether the works caused the damage, what it will cost to put right, and whether the adjoining owner takes a repair or a payment instead. This guide explains how that process runs, what evidence decides it, and what changes when no notice was served.

What counts as party wall damage under the Act?

Section 7(2) covers "any loss or damage" resulting from work carried out in pursuance of the Act, so it is not limited to the party wall itself. The claims surveyors see most often involve:

• Cracking to plaster, render, brickwork or ceilings in the rooms nearest the works, typically after cutting in beams, underpinning or excavation.
• Movement of the adjoining structure, including dropped floors, sticking doors and windows or a lean to a garden wall.
• Water or damp penetration where flashings, weatherings or a party wall upstand have been disturbed.
• Damage to finishes and fittings, including decorations, tiling, fitted furniture and services.

Two limits apply. The damage must be caused by the notifiable works; pre-existing defects, seasonal cracking and unrelated movement are not the building owner's responsibility. And the adjoining owner is put back where they were, not somewhere better: like-for-like making good is the standard, and an upgraded finish is paid for by whoever wants it. The right extends to an adjoining occupier, so a tenant next door can claim too.

How is a party wall damage claim assessed?

The starting point is the schedule of condition prepared before the works began. This dated written and photographic record of the adjoining property is the benchmark against which every alleged crack or stain is compared. Our guide to how a schedule of condition is made explains what a good one contains.

When damage is noticed, the adjoining owner should tell their appointed surveyor (or the agreed surveyor) straight away and photograph it with something for scale. The surveyors then inspect and work through three questions:

• Is the damage new? Anything already recorded in the schedule of condition is excluded, which is why a thin or photograph-only schedule weakens both sides.
• Was it caused by the works? The surveyors weigh the location, pattern and timing of the damage against what the builder was doing and when. Where structural movement is suspected, crack monitoring over several weeks or a structural crack assessment by an engineer may be needed first.
• What will it cost to put right? The surveyors agree a specification for making good and usually obtain or review contractor quotations.

Where the two surveyors cannot agree, either can refer the point to the third surveyor selected at the start of the matter, whose decision is binding subject to appeal.

Repair or payment: how the claim is settled

Many awards already contain a damage clause, and a well-drafted award says who inspects and how making good is to be carried out. Once the surveyors determine that the works caused the damage, the building owner must make it good. The adjoining owner then has a choice many people do not know about: under section 11(8) they can require the cost of making good to be determined by the surveyors and paid to them instead, so they can appoint their own contractor rather than have the building owner's builder back in the house.

The surveyors record the outcome in an addendum award setting out the damage accepted, the sum or the works, and the timescale for payment or repair. Under section 10(13) the reasonable costs of dealing with the dispute, including inspection fees, are paid by whichever party the surveyors determine; where damage is proven that is almost always the building owner, in line with the position in our guide to who pays for a party wall surveyor. Where a claim is unsupported, the adjoining owner may be asked to bear some of the inspection costs.

As a general picture of the market, claims for decorative cracking are often resolved for a few hundred to a few thousand pounds, with surveyors' time charged at around £100–£250 an hour. Structural damage from excavation or underpinning usually brings in a structural engineer to specify the remedial works.

What if no party wall notice was served?

If the building owner started notifiable work without serving notice, the Act's dispute machinery is not available and the adjoining owner is left with their common-law rights. Damage caused by a neighbour's building work can be pursued in nuisance, negligence or trespass in the county court, and an injunction can be sought to stop works under way. Our guide to what happens if the building owner ignores the Party Wall Act covers the options at each stage.

The practical difficulty is evidence. Without a schedule of condition, the adjoining owner must prove what the property looked like before the works and that the works caused the change. Dated photographs taken as soon as works are noticed, a defect report from a chartered surveyor and, in larger cases, an engineer's opinion on causation all help. The Limitation Act 1980 generally allows six years to bring a claim, but the case is far stronger if the evidence is gathered at the time.

When a party wall damage claim goes to court

Court is the exception, and it arises in two ways. Either owner can appeal an award, including an addendum award on damage, to the county court within 14 days of service under section 10(17); the court can rescind or modify the award. Alternatively the claim is a common-law action because no notice was served or the damage falls outside the Act.

In both routes the court will usually want independent expert evidence on cause and cost from a chartered surveyor or engineer complying with CPR Part 35, a different exercise from the appointed surveyor's statutory role. Our guides to the expert witness surveyor's role in party wall court cases and to using a schedule of condition as evidence explain what the court expects. Expert witness reports in straightforward property disputes typically run to £5,000–£15,000, with court attendance at £1,000–£2,000 per day.

How both owners can protect themselves

For adjoining owners, the most valuable step is a thorough schedule of condition before works start, covering floors, ceilings, window operation and the garden as well as the nearest walls. Report damage promptly and in writing, leave it undisturbed until inspected, and for basement or underpinning schemes ask the surveyors to consider security for expenses under section 12 so that funds exist if the making good is never completed. For building owners, the same schedule is the best defence against claims for old cracks; check that the contractor's insurance covers neighbouring property, and deal with genuine damage quickly, because a prompt repair is almost always cheaper than a contested addendum award.

Party wall damage support from Survey Merchant

Survey Merchant provides RICS party wall surveyors through its party wall services, drawn from a national panel of 2,400+ chartered surveyors who prepare schedules of condition, act as agreed or adjoining owner's surveyor, inspect alleged damage and determine claims by addendum award. Where a claim is heading for the county court, or no notice was served and a common-law claim is the only route, the panel's party wall expert witness surveyors prepare CPR Part 35 reports on the cause, extent and cost of damage, and the panel can pair the surveyor with a structural engineer where movement is in issue. Coverage includes London and the major cities. Fixed fees are quoted up front; contact Survey Merchant or call 0204 579 8270.