Preliminary Ecological Appraisal

Councils ask for a PEA when a site has features that protected species use: hedges, mature trees, scrub, rough grassland, water, or old buildings. It is common on new homes in gardens and fields, barn conversions, small housing schemes and commercial sites on the edge of town.

Many councils name it on their local validation checklist, so an application can be refused registration without one. Others ask during the application, often after their own ecologist has looked at the plans. Either way, the council is following Natural England’s standing advice on when to ask for surveys for bats, newts, reptiles and badgers (gov.uk).

A PEA has two parts. The desk study pulls records of protected and notable species and designated sites within a set distance, usually from the local environmental records centre, and looks at maps and aerial photographs for ponds and links to the wider countryside. The walkover maps every habitat on the site and notes signs and features that species use.

On many small sites the appraisal finds nothing that needs further work, and the report goes in with the application. Where it does find potential, it will recommend specific surveys: dusk bat surveys for a building with roost potential, a water sample from a nearby pond for great crested newts, or reptile checks on rough grassland.

Those follow-up surveys run only in their seasons. That is why the timing of the PEA matters: a PEA in October that recommends bat emergence surveys means waiting until May. Our survey calendar shows each window.

Where a PEA is written up for submission to a council, it is often called a preliminary ecological appraisal report or an ecological impact assessment. On larger schemes the ecologist may combine the findings of all the surveys into one ecological impact assessment.

For a single plot or a small site, a PEA is typically £500 to £1,200 plus VAT. Larger or more complicated sites, with several fields, woodland or many buildings, can reach about £2,000. The records centre charges separately, often £100 to £300, and some ecologists add mapping costs.

Ask for the habitat survey to be done in a way that can be reused for a biodiversity net gain baseline if your project will need one. It saves paying for a second visit. The survey cost guide has every survey type.