The further survey section of an ecological appraisal

The part of a preliminary ecological appraisal that decides your programme is the further surveys section. Everything before it describes what the ecologist saw on one visit. The recommendations tell you what cannot be concluded from that visit, which species surveys have seasons attached, and therefore whether you are submitting an application in March or in October.

Read it first. Then read the habitat description, because the two have to agree.

What the appraisal can and cannot conclude

A preliminary ecological appraisal combines a desk study of records and designations with a walkover of the site, following the approach in the guidance published by the Chartered Institute of Ecology and Environmental Management. It classifies habitats, records features of interest as target notes, evaluates the site, and identifies what further work is needed.

What it cannot do is prove absence. A single visit can establish that a building has no features suitable for roosting bats, and that is a conclusion about suitability. It cannot establish that bats are not using a building with lifted tiles and gaps at the ridge. The same logic applies to newts in a pond 80 m away, to reptiles in a rough grassland margin, and to badgers on a site walked in July with the vegetation two metres high.

So the appraisal deals in likelihood. Where the likelihood is more than negligible and the proposal would affect the feature, further survey follows. A Preliminary Ecological Appraisal that concludes "no protected species present" after one walkover is a report to send back.

Habitat description and target notes

The habitat map and the target notes are the evidence base for everything else, including the biodiversity baseline. Each habitat parcel should carry a classification consistent with the system the statutory biodiversity metric uses, an area, a condition judgement against the metric's criteria, and a note of what was observed.

Target notes are where the useful detail sits: a mature ash with a woodpecker hole, a pile of corrugated sheets, a south facing bank, a drain that runs to a pond off site, a hedgerow with a ditch and standard trees. Each of those is a reason for a recommendation later, and a reader should be able to trace the line from note to recommendation.

Check the survey date and the weather. A February walkover cannot describe a grassland sward, and an appraisal that classifies species diverse grassland from a winter visit is stating something it cannot support.

Assessing likelihood of protected species

For each species or group, the appraisal should say what was looked for, what was found, what the desk study returned, and what the conclusion is. Bats are assessed through a preliminary roost assessment, which gives buildings and trees a roost suitability category of negligible, low, moderate or high, following the current good practice guidelines published by the Bat Conservation Trust.

That category drives the survey effort. Negligible suitability needs nothing further. Low suitability typically needs one emergence or re-entry survey, moderate suitability two, and high suitability three, spread across the season. Trees with potential roost features may need climbing inspection or endoscope work rather than, or as well as, emergence survey.

Great crested newts are assessed from pond locations within a few hundred metres and a habitat suitability index for each accessible pond, leading either to environmental DNA sampling or to population surveys, or to entry into a district level licensing scheme where one operates. Reptiles, badgers, dormice, water voles, breeding birds and wintering birds each have their own triggers, and the appraisal should name the trigger rather than simply listing species.

Recommending further survey proportionately

Proportionality runs both ways, and a good appraisal says no as often as it says yes. Survey effort should match the likely effect of the proposal and the value of the feature, and there is nothing to be gained from a full reptile survey on a site of mown amenity grass with no refugia and no connectivity.

Signs that the recommendations are proportionate:

• each recommendation names the species or group, the method, the number of visits and the season
• each is tied to a specific feature recorded in the target notes or the desk study
• the report explains what decision the survey will inform, such as whether a licence is needed or where mitigation goes
• alternatives are considered, including precautionary working methods where survey would add nothing
• recommendations distinguish work needed before determination from work that can properly follow a permission

That last distinction is worth understanding. National policy expects surveys to be carried out before determination where there is a reasonable likelihood of a protected species being present and affected, because the authority has to consider the effect and, where a European protected species licence will be needed, the derogation tests. A pre-commencement condition requiring a survey that could change whether the scheme is acceptable is not a lawful substitute for doing it first.

Survey seasons and the effect on programme

Two months of the year cause most of the damage to a programme. If the appraisal lands in late September and recommends bat emergence surveys, the next window opens in May. If it lands in July and recommends newt eDNA, that window closed on 30 June.

So commission the appraisal early, before the design is fixed, and ask the ecologist at instruction stage which seasonal surveys the site is likely to trigger. A walkover in February that flags a likely bat survey requirement still leaves time to plan for May.

Where an appraisal is enough on its own

Plenty of sites need nothing more. A brownfield yard of hardstanding with a modern steel building, no vegetation and no water within a few hundred metres, where the appraisal records negligible suitability across the board, can be submitted on the appraisal alone, with precautionary measures and enhancement secured by condition.

Even then, two obligations remain. The habitat baseline for biodiversity net gain still has to be established and the statutory metric completed, and a Biodiversity Net Gain Assessment under the Environment Act 2021 regime expects that work from a competent person, with the gain plan approved by the authority. And nesting birds remain protected during the season regardless of survey findings, so vegetation clearance timing still needs managing.

Reading the recommendations as a developer

Illustrative example. A 0.4 hectare site with a 1960s bungalow, a detached garage with a felt roof, a mature beech and a rear garden of mown lawn with a hedgerow boundary. The appraisal returns moderate roost suitability for the bungalow, low for the garage, two potential roost features in the beech, negligible reptile potential, and a hedgerow requiring retention or replacement in the metric. Two bat emergence surveys between May and August, a climbing inspection of the beech, and nothing else.

What that means in practice: the application can be prepared now, the bat surveys have to be done before determination because a roost would engage licensing, and the earliest realistic submission is June. Where a roost is confirmed, the mitigation and any licence application require a suitably licensed ecologist under the Wildlife and Countryside Act 1981 and the Conservation of Habitats and Species Regulations 2017. A Protected Species Survey and the licence work that follows are legally the province of that licensed person, and an AI-assisted draft is a starting point for them rather than a substitute.

Finally, check validity. Survey data ages, and many authorities treat results more than two years old as needing an update, particularly where the site has been cleared, the buildings have deteriorated, or a pond has been lost. Where a scheme stalls for a season, budget for the refresh rather than discovering it at validation. The same discipline about dated baselines applies to larger schemes, as the treatment of the baseline chapter of an environmental statement shows.

To see which ecology and biodiversity reports a site is likely to need, enter the postcode on PlanScope.

This is general guidance rather than 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.