# Do i need a bat survey for planning permission (2 sources)

> The Bat Survey Season And Validity carries 2 published figures read from 2 sources' own pages, from 18 to 24 month, read 15 September 2026.

Asbestos Survey Cost · https://asbestossurveycost.co.uk/datasets/bat-survey-season-and-validity/ · computed 2026-09-15

**Median of the published figures:** 21 month (range 18 to 24 month; 2 sources with a figure; 2 of 17 sources read publish one).

2 of the 17 named sources read in full publish a figure; 15 publish none, read 15 September 2026.

## By jurisdiction

| Breakdown | Median | Range | Sources |
|---|---|---|---|
| jurisdiction Scotland | 18 month | 18 to 18 month | 1 |
| jurisdiction England | 24 month | 24 to 24 month | 1 |

## Every figure, with its source

One row per source: the figure the source's own page publishes, the page, and the day it was read.

| Source | Figure | Breakdown | Read |
|---|---|---|---|
| [Natural England - licence to survey bats for scientific or educational purposes, level 2 (CL18)](https://www.gov.uk/government/publications/bats-survey-or-research-licence-level-2/bats-survey-or-research-licence-level-2-cl18) | 24 month | England | 2026-09-12 |
| [NatureScot - standing advice for planning consultations, bats](https://www.nature.scot/doc/standing-advice-planning-consultations-bats) | 18 month | Scotland | 2026-09-11 |

## The sentence each figure was read from (2)

- [Natural England - licence to survey bats for scientific or educational purposes, level 2 (CL18)](https://www.gov.uk/government/publications/bats-survey-or-research-licence-level-2/bats-survey-or-research-licence-level-2-cl18), read 2026-09-12: "The Registered Person must maintain a record, which must be kept for at least 24 months beyond the expiry date of this licence, in accordance with the requirements of Annex A."
- [NatureScot - standing advice for planning consultations, bats](https://www.nature.scot/doc/standing-advice-planning-consultations-bats), read 2026-09-11: "bat surveys have been carried out by a licensed ecologist in accordance with the best practice outlined above, and within the last 18 months;"

## Read in full, publishes no figure

- [Natural England - bats: surveys and mitigation for development projects](https://www.gov.uk/guidance/bats-surveys-and-mitigation-for-development-projects), read 2026-09-11: read in full and no accepted figure on the page
- [Natural England - protected species and development: advice for local planning authorities](https://www.gov.uk/guidance/protected-species-and-development-advice-for-local-planning-authorities), read 2026-09-12: read in full and no accepted figure on the page
- [Natural England - great crested newts: surveys and mitigation for development projects](https://www.gov.uk/guidance/great-crested-newts-surveys-and-mitigation-for-development-projects), read 2026-09-12: read in full and no accepted figure on the page
- [Natural England - wild birds: surveys and mitigation for development projects](https://www.gov.uk/guidance/wild-birds-surveys-and-mitigation-for-development-projects), read 2026-09-12: read in full and no accepted figure on the page
- [GOV.UK - class licences for wildlife management](https://www.gov.uk/government/collections/class-licences-for-wildlife-management), read 2026-09-12: read in full and no accepted figure on the page
- [Natural England - European protected species policies for mitigation licences](https://www.gov.uk/guidance/european-protected-species-policies-for-mitigation-licences), read 2026-09-12: read in full and no accepted figure on the page
- [Natural England - bats: apply for a mitigation licence (A13)](https://www.gov.uk/government/publications/bats-apply-for-a-mitigation-licence), read 2026-09-12: read in full and no accepted figure on the page
- [DAERA - plant or animal species protected by law (Northern Ireland)](https://www.daera-ni.gov.uk/articles/plant-or-animal-species-protected-law), read 2026-09-11: read in full and no accepted figure on the page
- [DAERA/NIEA - guidance on bat surveys, assessment and mitigation for onshore wind turbine developments in Northern Ireland](https://www.daera-ni.gov.uk/publications/niea-natural-environment-division-guidance-bat-surveys-assessment-and-mitigation-onshore-wind), read 2026-09-12: read in full and no accepted figure on the page
- [Ministry of Housing, Communities and Local Government - planning practice guidance, natural environment](https://www.gov.uk/guidance/natural-environment), read 2026-09-12: every candidate on the page was refused
- [The Conservation of Habitats and Species Regulations 2017](https://www.legislation.gov.uk/uksi/2017/1012/contents/made), read 2026-09-12: read in full and no accepted figure on the page
- [Wharton - ecology survey calendar](https://wnic.co.uk/ecology-survey-calendar/), read 2026-09-12: read in full and no accepted figure on the page
- [Bat Conservation Trust - Bat Surveys for Professional Ecologists, Good Practice Guidelines 4th edition](https://www.bats.org.uk/resources/guidance-for-professionals/bat-surveys-for-professional-ecologists-good-practice-guidelines-4th-edition), read 2026-09-12: every candidate on the page was refused
- [CIEEM - advice note on the lifespan of ecological reports and surveys](https://cieem.net/wp-content/uploads/2019/04/Advice-Note.pdf), read 2026-09-12: read in full and no accepted figure on the page
- [the nature body per jurisdiction](https://www.gov.uk/guidance/bats-surveys-and-mitigation-for-development-projects), read 2026-09-11: read in full and no accepted figure on the page

## Methodology

Every row is a verbatim sentence read from the named source's own page through the estate's fetch service on the date shown, hash-pinned to the stored read (the sha of the page's visible text; the raw page is mirrored to R2). 2 of the 17 named sources that could be read published a usable figure; 15 published none and are recorded as not published, never filled in; 1 could not be read (blocked, dead or unreachable) and count nowhere. The headline figures (median, minimum, maximum, quartiles) are over ONE figure per source in month (a source's median where its page yielded several accepted sentences), so N counts sources, never sentences; 11 candidate sentence(s) were refused by a reviewer with the reason recorded. Derivation as chartered: one row per jurisdiction per rule: what triggers a survey requirement, which survey type is possible in which months, what licence the work needs and from whom, and how long a report is accepted for - each quoted from that jurisdiction's own nature body, with the four nations side by side, which no authority does because each publishes only its own. The derived figure the buyer actually wants: the LAST DATE this year on which each survey type can still be commissioned, computed per jurisdiction from the season window, and the count of weeks a project is delayed if that date is missed. Changed-since on every guidance update.

## Sources

- [Natural England - bats: surveys and mitigation for development projects](https://www.gov.uk/guidance/bats-surveys-and-mitigation-for-development-projects) (the publisher's own terms; quoted for reporting and comment)
- [Natural England - protected species and development: advice for local planning authorities](https://www.gov.uk/guidance/protected-species-and-development-advice-for-local-planning-authorities) (the publisher's own terms; quoted for reporting and comment)
- [Natural England - great crested newts: surveys and mitigation for development projects](https://www.gov.uk/guidance/great-crested-newts-surveys-and-mitigation-for-development-projects) (the publisher's own terms; quoted for reporting and comment)
- [Natural England - wild birds: surveys and mitigation for development projects](https://www.gov.uk/guidance/wild-birds-surveys-and-mitigation-for-development-projects) (the publisher's own terms; quoted for reporting and comment)
- [GOV.UK - class licences for wildlife management](https://www.gov.uk/government/collections/class-licences-for-wildlife-management) (the publisher's own terms; quoted for reporting and comment)
- [Natural England - licence to survey bats for scientific or educational purposes, level 2 (CL18)](https://www.gov.uk/government/publications/bats-survey-or-research-licence-level-2/bats-survey-or-research-licence-level-2-cl18) (the publisher's own terms; quoted for reporting and comment)
- [Natural England - European protected species policies for mitigation licences](https://www.gov.uk/guidance/european-protected-species-policies-for-mitigation-licences) (the publisher's own terms; quoted for reporting and comment)
- [Natural England - bats: apply for a mitigation licence (A13)](https://www.gov.uk/government/publications/bats-apply-for-a-mitigation-licence) (the publisher's own terms; quoted for reporting and comment)
- [NatureScot - standing advice for planning consultations, bats](https://www.nature.scot/doc/standing-advice-planning-consultations-bats) (the publisher's own terms; quoted for reporting and comment)
- [Natural Resources Wales - protected species licensing](https://naturalresources.wales/permits-and-permissions/protected-species-licensing/) (the publisher's own terms; quoted for reporting and comment)
- [DAERA - plant or animal species protected by law (Northern Ireland)](https://www.daera-ni.gov.uk/articles/plant-or-animal-species-protected-law) (the publisher's own terms; quoted for reporting and comment)
- [DAERA/NIEA - guidance on bat surveys, assessment and mitigation for onshore wind turbine developments in Northern Ireland](https://www.daera-ni.gov.uk/publications/niea-natural-environment-division-guidance-bat-surveys-assessment-and-mitigation-onshore-wind) (the publisher's own terms; quoted for reporting and comment)
- [Ministry of Housing, Communities and Local Government - planning practice guidance, natural environment](https://www.gov.uk/guidance/natural-environment) (the publisher's own terms; quoted for reporting and comment)
- [The Conservation of Habitats and Species Regulations 2017](https://www.legislation.gov.uk/uksi/2017/1012/contents/made) (the publisher's own terms; quoted for reporting and comment)
- [Wharton - ecology survey calendar](https://wnic.co.uk/ecology-survey-calendar/) (the publisher's own terms; quoted for reporting and comment)
- [Bat Conservation Trust - Bat Surveys for Professional Ecologists, Good Practice Guidelines 4th edition](https://www.bats.org.uk/resources/guidance-for-professionals/bat-surveys-for-professional-ecologists-good-practice-guidelines-4th-edition) (the publisher's own terms; quoted for reporting and comment)
- [CIEEM - advice note on the lifespan of ecological reports and surveys](https://cieem.net/wp-content/uploads/2019/04/Advice-Note.pdf) (the publisher's own terms; quoted for reporting and comment)
- [the nature body per jurisdiction](https://www.gov.uk/guidance/bats-surveys-and-mitigation-for-development-projects) (the publisher's own terms; quoted for reporting and comment)

## Cite or embed

- The Bat Survey Season And Validity carries 2 published figures read from 2 sources' own pages, from 18 to 24 month, read 15 September 2026.
- 2 of the 17 named sources read in full publish a figure; 15 publish none, read 15 September 2026.
- Bat Survey Season And Validity, jurisdiction Scotland: median 18 month across 1 source, read 15 September 2026.
- Bat Survey Season And Validity, jurisdiction England: median 24 month across 1 source, read 15 September 2026.

Cite as: "Asbestos Survey Cost Bat Survey Season And Validity", updated 2026-09-15, https://asbestossurveycost.co.uk/datasets/bat-survey-season-and-validity/.

CSV: https://asbestossurveycost.co.uk/datasets/bat-survey-season-and-validity.csv
JSON: https://asbestossurveycost.co.uk/datasets/bat-survey-season-and-validity.json
Embed (plain HTML, static link back): see https://asbestossurveycost.co.uk/datasets/bat-survey-season-and-validity/#median