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Slate roof slope with a rooflight set into it, seen from the roof of a house being renovated

Blog: planning

How much does a bat survey cost in London?

By Property Architecture drawing team, chartered architectural technologists (MCIAT). Published . 3 minute read.

A preliminary bat roost assessment for a London roof or loft project costs £495 from us, with no VAT to add, carried out by an ecologist through our partners. It is the first step in deciding whether a roof can be altered safely. The law is clear: all bat species, their breeding sites and resting places are fully protected by lawGOV.UK, Bats: protection and licences.

From £495 total

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  • £2m PI insured
  • LABC Partnered
  • Fixed fees, no VAT to add

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    Key takeaways

    What the first survey costs

    Our fee is £495 for the preliminary assessment. An ecologist inspects the building and its surroundings for signs of bats and for features they could use, then reports whether further surveys are needed. The result goes to the council with your planning application. See our bat survey page for the full description.

    It is a preliminary step, not the whole job. If the ecologist finds no evidence and little potential, that is often the end of it. If there is potential, further surveys follow, and they are priced separately because they depend on what is found.

    What the fee includesA check of whether your council is likely to ask for a survey; A preliminary roost assessment by an ecologist; A written result for the planning application; Advice on further surveys, if needed; Measures fitted to your drawingsWhat the fee includesA check of whether your council islikely to ask for a surveyA preliminary roost assessment by anecologistA written result for the planningapplicationAdvice on further surveys, if neededMeasures fitted to your drawingsFixed fee from £495, no VAT to add
    What our preliminary bat roost assessment includes.

    Why the law matters to a roof project

    Bats have strong legal protection. all bat species, their breeding sites and resting places are fully protected by lawGOV.UK, Bats: protection and licences. It is an offence to damage a roost deliberately or otherwise: damaging or destroying a breeding site or resting place of a European protected species is an offenceConservation of Habitats and Species Regulations 2017, regulation 43. A loft conversion lifts tiles, opens the ridge and works in the roof void, which is where roosts are.

    That is also why councils ask for a survey with certain applications. A building with the right features, or a large garden, is a trigger: buildings with features suitable for bats, or large gardens in suburban and rural areasGOV.UK, Protected species and development: advice for local planning authorities. Our constraints check, from £19, flags whether your council is likely to ask.

    New timber roof rafters set out over a masonry wall during a house renovation
    Old roof timbers and gaps under tiles are the features an ecologist looks for. Photo: Bryn Pinzgauer, CC BY 2.0

    When surveys can be done

    A preliminary assessment can be done at any time. Further surveys depend on the season: May to AugustGOV.UK, Protected species and development: advice for local planning authorities, and November to mid-MarchGOV.UK, Protected species and development: advice for local planning authorities. Missing the season does not cancel the requirement; it delays the survey until the next one.

    If a project is in the planning stage in autumn, ask for the assessment early. A finding of potential in November can mean waiting until May to complete the work needed for the application, and that adds months.

    What the result means

    There are three outcomes. No evidence and low potential: you proceed. Evidence or potential: further surveys during the season, then a mitigation plan. Roosts that cannot be avoided: if you cannot avoid harming bats or their habitats, you can apply for a mitigation licence from Natural EnglandGOV.UK, Bats: protection and licences. The licence is an additional step, with its own cost, and the ecologist advises on it.

    The strongest protection for your project is the early look. A design that keeps a roost, or works around it, is cheaper than one that needs a licence.

    How the job runs, step by stepFree constraints check, including whether your council asks for a survey Then: Ecologist visits and inspects the roof and surroundings Then: Preliminary roost assessment written Then: Further surveys arranged in season, if needed Then: Result added to the planning application Then: Measures drawn into the designFree constraints check, includingwhether your council asks for a surveyEcologist visits and inspects the roofand surroundingsPreliminary roost assessment writtenFurther surveys arranged in season, ifneededResult added to the planningapplicationMeasures drawn into the design
    From a first assessment to a result the council can accept.

    How it fits with the drawings

    The survey result goes into the application alongside the drawings. Our loft conversion drawings and planning drawings are prepared to match, and any measures the ecologist recommends, such as a bat box or a particular tile, are drawn in.

    If the council asks for more detail, we coordinate the response with the ecologist.

    The figures, with sources

    Legal protection of bats
    all bat species, their breeding sites and resting places are fully protected by lawGOV.UK, Bats: protection and licencesChecked 25 October 2026
    Who can survey
    you'll need an expert to do a bat surveyGOV.UK, Bats: protection and licencesChecked 25 October 2026
    Mitigation licence
    if you cannot avoid harming bats or their habitats, you can apply for a mitigation licence from Natural EnglandGOV.UK, Bats: protection and licencesChecked 25 October 2026
    Timing of a preliminary roost assessment
    any time of yearGOV.UK, Protected species and development: advice for local planning authoritiesChecked 25 October 2026
    Season for summer roost surveys
    May to AugustGOV.UK, Protected species and development: advice for local planning authoritiesChecked 25 October 2026
    Season for hibernation roost surveys
    November to mid-MarchGOV.UK, Protected species and development: advice for local planning authoritiesChecked 25 October 2026
    Habitats where bats should be looked for
    buildings with features suitable for bats, or large gardens in suburban and rural areasGOV.UK, Protected species and development: advice for local planning authoritiesChecked 25 October 2026
    Offence of damaging a roost
    damaging or destroying a breeding site or resting place of a European protected species is an offenceConservation of Habitats and Species Regulations 2017, regulation 43Checked 25 October 2026

    Questions

    Do I need a bat survey for every loft conversion?

    Not always. It depends on the building and your council. We check at the constraints check and tell you before you pay.

    Can I do the survey myself?

    No. The government guidance says you need an expert to do a bat survey, and a council will only accept a report from a qualified ecologist.

    What if bats are found?

    The first step is to see if the work can avoid them. If not, a mitigation licence from Natural England may be possible. The ecologist advises, and we adjust the drawings.

    Does the fee cover follow-up surveys?

    No. The quoted fee is for the preliminary assessment. Follow-up surveys depend on what is found and are quoted separately.

    Header photo: A slate roof pitch with a rooflight set into it, seen from the roof of a house being renovated by Gareth1953 All Right Now, CC BY 2.0.

    The fixed fee for bat surveys

    Fixed fee
    from £495
    Total you pay
    from £495
    Council fee
    paid to the council separately

    No VAT to add. The fee is fixed in writing after a free constraints check of your address.

    What you get

    • A check of whether your council is likely to ask for a survey
    • A preliminary roost assessment by an ecologist
    • A written result for the planning application
    • Advice on further surveys, if needed
    • Measures fitted to your drawings
    • More about our bat surveys
    Request your fixed quoteCall 020 7131 9703
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    Tell us about your property.

    We check the constraints, then send a fixed fee. Messages before 3pm get a reply the same working day.

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