Sensitive area: the EIA definition that removes thresholds

"Sensitive area" is a defined term in regulation 2(1) of the Town and Country Planning (Environmental Impact Assessment) Regulations 2017, and its effect is blunt: if any part of your development falls inside one, the Schedule 2 thresholds stop applying. A scheme that would have been far too small to trouble anyone becomes Schedule 2 development requiring a screening decision, purely because of where it sits.

That is the whole meaning of a sensitive area in EIA terms. It does not make EIA compulsory. It removes the size filter that would otherwise have kept the scheme out of the regime altogether.

Which designations count

The definition lists specific designations. Sites of special scientific interest notified under section 28 of the Wildlife and Countryside Act 1981, National Parks, the Broads, properties on the World Heritage List, scheduled monuments, areas of outstanding natural beauty, now branded National Landscapes, and European sites for habitats and birds all fall within it.

Read regulation 2(1) itself before relying on any summary, including this one, because the list is exhaustive and the boundaries of each designation are precise.

What is not on the list matters as much as what is. Conservation areas are not sensitive areas. Nor are listed buildings, registered parks and gardens, local wildlife sites, ancient woodland, green belt, Local Green Space or flood zone 3. Those designations carry their own policy weight and may well drive a screening decision on their merits, but none of them removes the threshold.

Two entries catch people repeatedly. Scheduled monuments are often small and unmarked on the ground, and a field boundary earthwork can bring a barn conversion into Schedule 2. And European site boundaries frequently follow a river or an estuary channel, so a site that feels well inland can clip one.

Why the thresholds fall away

Schedule 2 lists categories of development in column 1 and applicable thresholds or criteria in column 2: an urban development project above a stated site area, an intensive livestock installation above a stated number of places, and so on.

The definition of Schedule 2 development treats a proposal as falling within the schedule where it is of a description in column 1 and either the column 2 threshold is met or exceeded, or any part of the development is to be carried out in a sensitive area. Those are alternatives. Inside a designation, the numbers in column 2 simply do not engage.

The logic is that the same physical works produce different effects depending on the receiving environment, which is the principle running through the whole regime. A hundred square metres of hardstanding is nothing in a business park and something quite different on a scheduled monument.

Screening is not assessment

A great many people hear "sensitive area" and assume an Environmental Impact Assessment is now unavoidable. It is not.

What follows is a screening decision: does the development, by virtue of factors such as its nature, size or location, give rise to likely effects on the environment of a kind that requires an environmental statement? The authority applies the selection criteria in Schedule 3, which cover the characteristics of the development, its location, and the type and characteristics of the potential impact.

Most small schemes inside a sensitive area screen out. A modest extension to a visitor centre in a National Park, a farm track, a replacement dwelling within a National Landscape: these routinely produce a negative screening opinion with a short reasoned conclusion. What has changed is that somebody now has to make and record that decision, and the application cannot be validated without it.

That is a programme cost of about three to five weeks and a consultant fee, not a six-figure environmental statement.

Checking whether a site is inside one

Do this before the option agreement, not after.

1. Check the statutory designations on the Defra MAGIC map, which carries SSSIs, National Parks, National Landscapes, European sites and scheduled monuments in a single view.
2. Cross-check boundaries against the planning data platform, which publishes the datasets behind many of these designations in a form you can interrogate.
3. Order the historic environment record search from the county archaeologist where any earthwork or building of interest sits on or near the land.
4. Ask the local planning authority to confirm the designations it holds for the site, in writing, as part of any pre-application enquiry.

Boundaries are the issue, not existence. Designation edges were drawn at various dates and at various scales, and a red line that looks clear at 1:10,000 can be ambiguous at 1:1,250. Where the boundary runs through your site, assume you are inside it until someone with the authoritative dataset says otherwise.

Sites next to a sensitive area

The threshold test turns on whether part of the development is to be carried out inside the designation. Adjoining land does not trigger it.

But the screening judgement is a different question, and a scheme immediately outside a European site or an SSSI can have obvious effects inside it through hydrology, air quality, recreational pressure or noise. The Schedule 3 criteria expressly direct the authority to the environmental sensitivity of areas likely to be affected, not merely the land within the red line.

So a poultry unit 400 metres upwind of an SSSI may screen in on ammonia deposition even though the threshold was not removed. Separately, an assessment under the habitats legislation may be required regardless of the EIA position, and the two regimes run in parallel rather than one substituting for the other. Early ecological input through a preliminary ecological appraisal usually tells you which of the two is going to drive the programme.

Making the screening request

Request a screening opinion from the authority under regulation 6 rather than waiting for the council to raise it at validation. The request needs a plan identifying the land, a description of the development and its possible effects on the environment, and any information you wish to provide on how those effects could be avoided.

The authority must adopt a screening opinion within three weeks, or a longer period agreed in writing. Where the answer is negative, the written statement of reasons goes in the application pack and removes the argument later.

Write the request as if you were writing the negative opinion yourself. Set out the designation, explain why the effects on the features of interest are not likely to be effects of the scale the regime is concerned with, and reference the supporting work already done, such as an archaeological desk-based assessment on a scheduled monument site. Officers under pressure adopt well-reasoned requests.

Before you commit to the land

Price the screening step into the appraisal. It is modest, but it is not zero, and it sits on the critical path because the application cannot be validated without the decision.

Then look at what the designation does to the rest of the evidence base. Sensitive areas rarely arrive alone: a scheme in a National Landscape needs landscape and visual work, a scheme near a European site needs ecology, a scheme on a scheduled monument needs archaeology and probably will not be consented at all. The threshold point is the least costly of those consequences.

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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.