The existing Knowledge Base explains what cumulative impact is; the practical task is to audit the cumulative scenario.

Create a project schedule showing operational, under-construction, consented and application-stage developments included by the applicant, together with any other categories required by the relevant methodology.

Check the cut-off date.

A cumulative assessment is prepared at a point in time. Later applications may not have existed when it was written. Record the assessment date before alleging that a project was omitted.

Check each technical topic separately.

The relevant cumulative study area and project list for landscape may differ from ecology, traffic, noise, hydrology or heritage. A single master list does not mean every development has a plausible cumulative interaction for every topic.

For landscape and visual effects, distinguish combined, successive and sequential experience.

NatureScot guidance recognises that cumulative experience depends on the distance between developments, visibility, landscape character, design and how the landscape is experienced.

Check whether the proposal's additional contribution is clear.

A cumulative assessment should allow the reader to understand what changes because the proposed development is added to the existing or future baseline.

Avoid treating every planned development as certain.

Different planning statuses carry different levels of certainty. Use the scenario definitions in the applicable methodology and explain why an omitted or included project matters.

Sources and further information

NatureScot - Assessing cumulative landscape and visual impact of onshore wind energy developments

Scottish Government - Information to be included in an EIA Report

GOV.UK - Environmental Impact Assessment

Last checked: 26 September 2026