Party walls in Singapore: what terrace and semi-detached owners must settle before demolition.

There is no Party Wall Act. There is liability.

Owners who have lived in the United Kingdom sometimes expect a Party Wall Act: a statutory procedure of notices, surveyors and awards. Singapore has none. What Singapore has instead is the Building Control Act, which requires a Qualified Person, almost always a Professional Engineer, to design and take responsibility for any structural work including work to a shared wall; and the ordinary law of nuisance and negligence, under which whoever causes damage to the neighbour's property, and failed to take reasonable care, pays for it.

That is a simpler regime than the British one and, for the unprepared, a harsher one. There is no neutral surveyor appointed by statute to referee. There is you, your builder, your engineer, your neighbour, and the evidence. The quality of that evidence, and the quality of the method, decide whether the rebuild ends with a handshake or with lawyers.

What URA requires when you detach from a neighbour

URA's development control guidelines for semi-detached houses are specific on three points. A new blank party wall at the common boundary is generally not allowed. When a house is detached from its neighbour, the developer must submit an engineer's certification of the structural stability of the remaining unit to BCA. And the exposed face of the neighbour's wall must be plastered and painted. The BCA "Be Good Neighbours" guide adds the practical courtesies: notice, working hours, dust and noise control, and a point of contact.

None of this requires your neighbour's consent. All of it requires their cooperation, which is a different and more valuable thing, and which is earned in the first week.

The seven things to settle before demolition

1. The dilapidation survey

A dated, photographed, measured record of the existing condition of both party walls and of the neighbour's adjacent rooms, floors, tiles and external finishes. Made jointly, with the neighbour present, and signed by both households, with a copy left next door. Crack gauges on any existing cracks. Floor levels taken. This single document separates the damage you caused from the damage that was already there. Without it, every crack discovered in the next eighteen months is yours.

2. The notice letter

To the whole row, not only the adjoining houses: what is being built, when demolition starts, the working hours that will be kept, who to call, and the number on the hoarding. Houses two and three doors down hear the piling rig as clearly as the neighbour does.

3. Temporary works designed by a Professional Engineer

When your half of a semi-detached house comes down, the shared wall loses the floors and roof that braced it. It must be propped, and the propping must be designed, not improvised by the demolition crew. Temporary works in Singapore are a PE's responsibility; this guide to temporary structure endorsement explains what the engineer certifies and why the builder cannot certify it for themselves.

4. The piling method

A 1970s terrace usually sits on shallow strip footings. If your new house is piled with a driven system next to those footings, the vibration travels straight into your neighbour's structure. Bored piles, taken below the level of the neighbour's footing, are slower and more expensive and are the right answer in most attached rebuilds. The choice depends on the soil, which is why a site investigation comes before the method statement; CVC Engineers' note on pile types and site investigation sets out how the decision is made.

5. Vibration and settlement monitoring

A monitor on the party wall, read daily, with the limit agreed in the method statement and the log kept. If the reading approaches the limit the sequence changes, that day, not after the neighbour's ceiling cracks. The log is also your evidence if a claim is made.

6. Insurance that would actually pay

Contractor's all-risks for the works and public liability for third-party property, with the sums insured written into the contract and the policy produced before demolition. Ask what the excess is and who pays it. A policy with a six-figure excess on third-party property damage is a policy that will not help your neighbour.

7. The make-good, written down

The exposed face of the shared wall plastered and painted, the boundary drain reinstated, the neighbour's damaged finishes repaired, and a final walk-through next door, against the dilapidation survey, before anyone calls the house finished. If it is not in the contract, it is a favour; favours are negotiable at the end of a long job.

Your neighbour is not your builder's client. Choose a builder who behaves as if they were.

Who is liable

Liability follows cause and care. If the works damage the neighbour's house, the party who caused the damage is liable, and the question is whether reasonable care was taken. In practice claims are made against the owner, who then looks to the contractor under the building contract and to the insurer under the policy. A well-drafted contract makes the contractor responsible for third-party damage arising from the works and requires the insurance above. A badly drafted one leaves you, the owner, holding a claim from the people you will live beside for the next twenty years.

When it goes wrong

Cracks appear next door. The first question is the survey: was it there before? The second is the log: what was the vibration that week? The third is the insurance: who is calling the insurer? If those three documents exist, most disputes end in a repair and an apology. If they do not, they end in the Community Disputes Resolution Tribunal or the courts, with a neighbour who will remember the rebuild for the rest of their lives. Everything in this article is cheaper than that.

Questions we are asked about neighbours

Can my neighbour stop me rebuilding?

Not by withholding consent, which is not required. They can object to URA on planning grounds during submission, and they can claim for damage. Neither happens often when the first week is handled well.

Who pays to plaster and paint the neighbour's exposed wall?

You do. It is a URA requirement when detaching, and it belongs in the quotation under external works and make-good, not as a later variation.

Does the engineer work for the builder?

No, and it should not. The Qualified Person is appointed independently and signs for the structure and the temporary works in their own name. Our guide to PE endorsement explains the role.