Treasure Act duties when a find appears on a building site

Treasure act obligations development site duties fall on whoever finds the object, not on the landowner and not on the main contractor. Under section 8 of the Treasure Act 1996, a finder must report anything they believe or have reason to believe is treasure to the coroner for treasure within 14 days of finding it, or within 14 days of first forming that belief. The duty is personal, it is criminal if ignored, and it applies whether or not the site has an archaeological condition attached to its permission.

That is the part developers most often get wrong. An approved written scheme of investigation deals with recording and analysis. It does not displace the statutory reporting duty, and a groundworker who pockets a coin has committed an offence regardless of what the condition says.

What counts as treasure

The definition in section 1 is mechanical rather than aesthetic. Age, material and context decide it, not whether the object looks important.

The main categories are coins at least 300 years old when found, where a single coin or a small group must contain gold or silver, and groups of ten or more coins from the same find qualify whichever metal they are made of. Objects other than coins at least 300 years old containing at least ten per cent gold or silver by weight also qualify. So do certain prehistoric base metal assemblages, anything found in the same place as an object that is treasure, and objects that would have counted as treasure trove under the old common law.

A further class was added in 2023 by designation order, covering metal objects at least 200 years old that are of outstanding historical, archaeological or cultural significance. That one matters on development sites, because it catches objects that fail the precious metal test but are archaeologically important.

What is not treasure: unworked natural objects, single base metal items outside the prehistoric categories, pottery, glass, bone and the great bulk of what actually turns up in a trench. Those finds are dealt with under the planning condition and the landowner's agreement, not under the Act.

Who has the duty and how the report is made

The duty sits with the finder. On a construction site that is usually a machine operator, a groundworker or a site archaeologist, and all three are capable of triggering it.

In practice the report is made through the local Finds Liaison Officer of the Portable Antiquities Scheme, who records the object and passes it into the treasure process. The coroner for treasure then decides whether an inquest is needed. A museum may express an interest in acquiring the object, in which case it is valued independently and a reward is paid.

Three things make this work smoothly on a live site:

1. A named person on site who is responsible for making the report, usually the archaeological monitor or the site manager.
2. A written instruction in the site induction telling operatives to stop, protect the find in position where possible, and notify that person immediately.
3. A record of the findspot to the nearest practical coordinate, because an object without a location loses most of its archaeological value and complicates the inquest.

The 14 day clock starts at the point of belief, which means the day someone on site thinks an object might be treasure, not the day a specialist confirms it. Report early and let the process decide.

Ownership, reward and the landowner's position

Treasure vests in the Crown, subject to prior interests and rights. If a museum acquires the object, the Treasure Valuation Committee advises on value and the reward is normally shared between the finder and the landowner or occupier.

Where no museum wants the object, it is disclaimed and usually returned to the finder or the landowner. Agreements between the parties about how any reward will be divided are common and lawful, and the time to make one is before any work starts, not after a find appears.

For a developer the financial outcome is rarely the issue. Programme is. The practical risk is an unplanned stoppage in a trench, so it is worth deciding in advance who pays for standing time and how long a stoppage is treated as a contractor's risk, and writing that into the contract.

Human remains are not treasure and should never be treated as a find. Stop, inform the police so the context can be established, and then follow the burial licensing route. That is a different legal track with its own consents.

Finds that are not treasure but still matter

Most of what an evaluation produces has no treasure status at all and considerable archaeological value. That is the territory of the planning condition, the approved written scheme of investigation and the eventual archive deposit, which is why the choice between a watching brief and an evaluation has such a strong effect on programme risk.

Desk based work reduces surprises. Historic mapping, aerial photography, Historic Environment Record entries and previous fieldwork within a sensible radius will usually tell you whether a site sits on a known focus of activity. The note on using historic maps in an assessment covers the sources and their limits, and the same material feeds the Archaeological Desk-Based Assessment that supports the application.

Where the desk study flags real potential, an Archaeological Field Evaluation before determination usually costs less than a condition that lands mid build. It also gives the county archaeologist something to agree to rather than something to worry about.

Metal detecting and site security

Development sites attract detectorists, invited and uninvited. Both carry risk.

Using a metal detector in a protected place, including a scheduled monument, without written consent is an offence under section 42 of the Ancient Monuments and Archaeological Areas Act 1979. Removing objects from such a place compounds it. On ordinary sites detecting is lawful with the landowner's permission, and a controlled detecting survey as part of an approved scheme can be useful for recovering metalwork from topsoil before it is stripped.

But uncontrolled detecting is the problem. Objects removed without a findspot cannot be interpreted, and the authority may treat the loss of evidence as a failure to comply with the condition. Lock the site, record permissions in writing, and make the position clear to anyone who asks for access.

Writing it into the contract and site documents

The documents that prevent trouble are short. An induction slide that explains what treasure is and who to tell. A clause in the subcontract requiring immediate notification and prohibiting removal of finds from site. A method statement paragraph covering what happens in the first hour after a find. A named archaeological contact with a mobile number on the site noticeboard.

Add a line about reward sharing to the landowner agreement, and a line about stoppages to the build contract. Neither takes long to draft and both remove an argument later.

If the application still needs its heritage and archaeology documents, PlanScope can draft a Heritage Statement and the supporting archaeological assessment from your project details, with flags where site specific evidence is still required.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.