Reporting archaeological discoveries during works

An archaeological discovery during construction rarely stops a site by operation of law. In England there is no general statutory duty to halt groundworks because something old has appeared. What stops the site is the planning condition you accepted, the written scheme of investigation approved under it, and in specific cases two separate legal duties: the obligation to report potential treasure to the coroner, and the requirement for a licence before human remains are moved.

Knowing which of those applies on the day the digger driver calls is the difference between a fortnight's delay and a three-month one.

Conditions that anticipate discoveries

Most archaeological control in the planning system runs through conditions, advised by the county archaeologist or the borough's historic environment adviser working from the Historic Environment Record. The usual pattern is a condition, applying before works start, requiring a written scheme of investigation to be submitted and approved, followed by implementation of that scheme and the deposition of an archive and a report.

The scheme itself specifies the mitigation, which might be a watching brief during groundworks, a strip-map-and-sample exercise, targeted excavation of defined areas, or preservation in situ with a design that avoids intrusion. It should also contain an unexpected discoveries clause setting out what happens if something outside the anticipated range appears, who is contacted, and how long work pauses while the discovery is assessed.

Read that clause before work starts rather than when the call comes. If it says work stops across the whole site rather than in the affected area, ask for it to be varied at the discharge stage. If it names a person who has since left the council, find out who replaced them.

An Archaeological Desk-Based Assessment done properly at application stage is what keeps this proportionate, because a scheme designed around a known risk is far less disruptive than one that meets the risk for the first time at formation level.

What to do when something is found

The sequence is the same on almost every site.

1. Stop work in the affected area only, unless the scheme says otherwise, and protect the find from weather and plant movement.
2. Call the retained archaeological contractor, who has the authority under the scheme to assess and record.
3. Notify the county archaeologist or the authority's historic environment adviser, in writing, the same day.
4. Record the position, the depth and the context before anything is lifted, with photographs and a survey point.
5. Agree, in writing, the revised mitigation and the extent of any further pause.

Do not let site staff lift or clean objects. Context is most of the evidential value, and an object removed from its stratigraphy has lost the information that made it worth recording.

Two designations change this picture. On a scheduled monument, any works need scheduled monument consent under the Ancient Monuments and Archaeological Areas Act 1979, and unconsented disturbance is a criminal offence. Part II of that Act also created Areas of Archaeological Importance, a designation applied to a small number of historic city centres, where an operations notice must be served before ground disturbance and a statutory pause follows. Outside those, the control is contractual and conditional rather than automatic.

Reporting obligations for treasure

The Treasure Act 1996 imposes a personal duty on the finder. Anyone who finds an object they believe or have reasonable grounds to believe is treasure must notify the coroner for the area within 14 days, beginning with the day after the find or the day the finder first believed it might be treasure.

The definition covers objects of a certain age and precious metal content, groups of coins found together, associated objects, and prehistoric base metal assemblages, with the detail set out in the Act and the subsequent designation orders. Failure to report without reasonable excuse is a criminal offence.

Practical points for a site. Tell the workforce before the first sod is turned, because the duty is on the individual who finds the object and not on the company. Record who found what and when. Finds that are not treasure can still be reported voluntarily to the local finds liaison officer, which costs nothing and builds the record.

Ownership matters to the landowner and the developer, since treasure vests in the Crown and a reward may be payable and shared. That is a matter to settle in the development agreement, not on site.

Human remains and the licence required

Human remains are the discovery most likely to stop a programme, and the rules are not archaeological in origin.

Remove the police from the equation first. Any discovery of human remains should be reported to the police and the coroner, who will establish whether the remains are of forensic interest. Once that is excluded, removal of remains from land requires a licence from the Ministry of Justice under section 25 of the Burial Act 1857, with conditions that normally require screening from public view, decent handling and reinterment or retention on agreed terms.

Where the remains are in consecrated ground of the Church of England, the route is different and runs through a faculty from the consistory court rather than a Ministry of Justice licence. Burial grounds in general use, closed churchyards and former nonconformist chapel sites each carry their own history, and the desk-based work should have identified them.

Licence applications take time. Build a contingency into the programme for any site with a burial ground, a former workhouse, an infirmary or a medieval church within or adjoining the red line.

Programme and cost consequences

Archaeology is the risk that most often lands outside the contingency because it is priced as a fixed watching brief and delivered as an open-ended excavation.

Three things reduce the exposure. Evaluation before groundworks, through trial trenching, gives a far better basis for pricing than a desk study alone. A written scheme that defines the trigger for escalation, and who authorises it, stops the contractor and the archaeologist negotiating in the trench. And a defined post-excavation allowance matters, because analysis, archive deposition and publication are frequently the larger half of the bill and arrive months after the site has closed.

Where a discovery is substantial enough to change the mitigation materially, the revised approach may need a formal variation. Where it changes the development itself, for example by requiring a foundation redesign to preserve remains in situ, a section 73 application to vary the relevant condition or a non-material amendment under section 96A may be needed. Agree the route with the case officer rather than assuming.

Recording, archive and publication afterwards

The obligation does not end when the concrete is poured. The approved scheme will require a report to a professional standard, deposition of the site archive with an agreed museum, and entry of a record onto the national online index of archaeological investigations and onto the Historic Environment Record.

Where standing buildings are affected, the equivalent obligation is a Historic Building Recording exercise to the appropriate Historic England level, completed before demolition rather than after it. And where the site also carries habitat obligations, the interaction between excavation areas and ecology mitigation is worth resolving early, as covered in our note on archaeology and biodiversity net gain on the same site.

Discharge of the condition depends on all of it. A site that has completed the fieldwork but never deposited the archive has an outstanding condition, which shows up on a purchaser's search years later.

Draft the heritage documents your scheme needs on PlanScope, including a Heritage Statement, then have them reviewed by a suitably qualified archaeologist before submission.

This is general guidance, not legal advice. Check the position with your local planning authority, the county archaeologist 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.