The short answer
Section 12 lets an adjoining owner require the building owner to provide security before exercising rights under the Act. It is a financial safeguard for genuine risk — not a punishment, a tactic or a general compensation fund — and it is not automatic; a request must be justified and the amount proportionate.
Why it matters
Security protects the adjoining owner where works are abandoned, where temporary support or protection becomes necessary, where damage is caused and funds are needed, or where they are otherwise exposed to financial risk. The amount should reflect real risk, not anxiety or caution, and if disputed the surveyors can determine it. It is most often considered for higher-risk works: basement excavations, underpinning and deep foundations, demolition and rebuilding where support may be lost, significant structural alterations to load paths, and complex or constrained sites. Security is usually money held in a separate account or another reliable mechanism — insurance is not the same thing, as a policy may not give immediate access to funds.
What to do now
- As an adjoining owner, justify the request by reference to the specific risk and likely cost if something goes wrong.
- Base the amount on the cost of temporary support or making safe, the value and vulnerability of your property, and the credibility of the contractor and programme — not the full project value.
- If need or amount is disputed, ask the surveyors to determine it.
Common mistakes
- Treating security as a tactic or a general compensation fund.
- Requesting an amount based on the project value rather than the real risk.
- Relying on insurance as if it gave immediate access to funds.
When to call Coburns
If higher-risk works are proposed next door, or you are asked for security, send us the details and we will advise on whether security is justified and how much is proportionate.