Prepared and maintained by Cambridge Development Archaeologyfor development teams working across Cambridge and Cambridgeshire.
Sources, review dates and corrections →How it works
Topsoil is removed under archaeological control across the development footprint. The exposed surface is then cleaned and mapped, so every feature is planned and recorded in position. Only a defined proportion of those features is then excavated — the sample — chosen to answer specific questions rather than to dig everything.
The result is a complete plan of the archaeology across the site, with excavation concentrated where it adds understanding. Nothing is lost unrecorded, because the mapping stage captures the full extent before the sampling decisions are made.
Why it is often cheaper than full excavation
In open-area excavation, the cost driver is the volume of hand excavation and the resulting quantity of finds, samples and specialist analysis. Strip, map and sample reduces that volume deliberately, while keeping the plan complete.
The saving is real but it is not automatic. If the stripped surface reveals dense, complex, well-preserved remains, the sampling percentage will rise, and the exercise can converge on full excavation. That is a risk to plan for, not a reason to avoid the method.
When an authority will accept it
Archaeological advisors accept strip, map and sample where the archaeology is expected to be dispersed rather than dense, and where the research value lies in the pattern across the site rather than in the exhaustive excavation of every feature.
- Large greenfield areas with scattered features identified by evaluation
- Field systems, boundary ditches, pits and dispersed rural settlement — common across Cambridgeshire
- Sites where geophysics and trial trenching already indicate the character and density of remains
- Schemes where the developed area is extensive and blanket excavation would be disproportionate
Where it is not appropriate
It is the wrong approach where remains are dense, stratified or of clear high significance — urban sequences, cemeteries, waterlogged deposits, or scheduled or near-scheduled contexts. In those situations sampling cannot answer the questions the authority will ask, and proposing it wastes the approval period.
Getting it into the approved scheme
The method is set in the Written Scheme of Investigation, agreed with the archaeological advisor before fieldwork starts. That is the moment at which the sampling strategy is negotiated, so it is the moment the commercial outcome is fixed. Once a scheme committing you to full excavation is approved, reducing it later is difficult.
If you have an evaluation report and a condition requiring mitigation, send both. Whether strip, map and sample is arguable on your site is usually clear from the trench results.