What an environmental impact assessment costs and why

Environmental impact assessment cost is driven by three things: how many topic chapters the scoping opinion requires, how many seasons of baseline survey those chapters need, and how many rounds of further information the authority asks for after submission. The regulations themselves add almost nothing in fees. Screening and scoping requests carry no charge, and the planning application fee is the same as it would be for any other scheme of that size.

That is why an EIA budget prepared from a fee schedule is always wrong. The money sits in specialist time, in the programme, and in the cost of holding a site for a 16 week determination period that frequently runs longer.

Screening and scoping requests and their fees

Schedule 1 of the Town and Country Planning (Environmental Impact Assessment) Regulations 2017 lists development where assessment is always required. Schedule 2 lists categories with thresholds where assessment is required only if the development is likely to have effects that matter, judged against the selection criteria in Schedule 3.

For a Schedule 2 scheme you can ask the authority for a screening opinion. There is no fee, and the authority must adopt an opinion within three weeks unless a longer period is agreed. A negative screening opinion is a useful document: it takes the question off the table and it is what a funder will ask for.

A scoping opinion is also free, and the period is five weeks. Requesting one is optional and usually worth it, because it converts an open-ended assessment into a defined list of chapters agreed with the authority and its consultees. Without a scoping opinion, the scope is whatever the applicant chooses, and the risk of a Regulation 25 request for further information after submission rises sharply.

The trade is time. Screening plus scoping consumes roughly two months before any survey work begins, and that is often the right two months to spend.

What drives the cost of an environmental statement

Four variables, in rough order of influence.

The number of chapters. Each topic chapter needs a baseline, an assessment method, a significance evaluation, mitigation and a residual effects conclusion, and each is written by a different specialist who has to be briefed and coordinated.

Survey seasons. Ecology sets the programme on most sites. Bat emergence surveys run from May to September, great crested newt environmental DNA from mid-April to the end of June, breeding birds from March to August, and botanical survey through the growing season. A scheme that starts in October and needs all four is looking at a full year of baseline work before the statement can be written.

Modelling. Air quality dispersion modelling, noise prediction, transport modelling and photomontage production from agreed viewpoints each carry their own software, data purchase and verification costs.

Consultee appetite. A site next to a designated habitat or in a nutrient neutrality catchment brings additional assessment that has nothing to do with the size of the scheme.

Chapter by chapter cost drivers

Not every chapter costs the same, and knowing which ones dominate helps a budget survive.

Ecology and transport are usually the two largest, and ecology is the one that determines when the others can be finalised. Where a scheme can be designed to avoid the habitats that trigger the longest survey programmes, the saving is measured in months rather than percentage points.

Coordination and technical review overhead

The chapters are written by different firms and the statement has to read as one document. Somebody has to make the cumulative effects chapter consistent with the individual chapters, ensure the mitigation commitments match across topics, and produce a non-technical summary a member of the public can read.

That coordination role is a real cost and it is often underestimated at appointment. The EIA Regulations require the environmental statement to be prepared by competent experts and to be accompanied by a statement of the expertise involved, which puts the coordinator's competence on the record too.

Budget also for the description of the proposed development itself. It has to be fixed early enough for the chapters to assess it, and every design change after that point ripples through every chapter. The single most reliable way to increase the cost of an environmental statement is to keep changing the scheme while it is being assessed.

An Environmental Impact Assessment is one of the report types where a licensed or competent professional is legally required. The regulations expect competent experts, so an AI-assisted draft is a structure and a starting point for that team, never a replacement for it.

The cost of avoiding EIA where that is possible

Designing below a Schedule 2 threshold is legitimate where the reduced scheme is actually the one you want to build. Splitting a project into parts to slip under a threshold is not, and authorities and inspectors treat salami slicing sceptically.

Where the threshold is exceeded but the effects are modest, a well-prepared screening request with supporting technical notes can produce a negative screening opinion. The notes cost money, and they cost far less than a full environmental statement. Expect to cover the same ground the screening criteria do: the scale and nature of the development, the sensitivity of the location and the character of the likely effects.

There is a residual risk. A negative screening opinion can be challenged, and a scheme built on a screening decision that later fails is in a much worse position than one that assessed properly. On a marginal case with a strong local objection group, the assessment sometimes costs less once the risk is priced.

Where screening is negative, some of the same technical work still gets done, because the authority will ask for the ecological appraisal and the transport work regardless. The saving is in the reporting apparatus rather than the underlying surveys.

Determination periods and holding costs

The statutory determination period for EIA development is 16 weeks rather than the 13 weeks for other major applications. In practice, applications routinely run longer through extensions of time, further information requests and committee cycles.

Holding costs over that period are usually the largest line nobody puts in the EIA budget. Land holding costs, professional fees during the determination period, and the delay to the revenue start date all belong in the same calculation as the consultant fees.

Two things shorten it. Agreeing the scope in advance so the further information requests are few and narrow. And publishing the statement in a form the consultees can actually use, with chapter-level summaries and a clear mitigation schedule, because a consultee who cannot find the answer sends a holding objection.

Deciding whether to request a screening opinion

Ask three questions. Is the development within Schedule 1, in which case assessment is required and screening is pointless. Is it within a Schedule 2 category and above the applicable threshold, or in a sensitive area where thresholds fall away. And would a funder, purchaser or objector be likely to challenge a decision taken without a screening opinion.

Where the answer to the third question is yes, request the opinion even if you are confident. It is free, it takes three weeks, and it converts an argument into a document.

For a comparison of what each report type involves and where professional input is required by law, the report index sets out all 66 types by category, and the pricing page shows what an AI-assisted draft costs against a consultant appointment.

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. For specialist technical reports, qualified professional input may be required.