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Rows of brick terraced houses and gardens on a residential street

Planning

Bat surveys for London roof and loft work

If your project touches a roof, a loft or an old tree, the council may ask whether bats use it. A preliminary roost assessment answers that question before the application goes in. We arrange it through an accredited ecologist and coordinate it with your drawings, from £495.

From £495, no VAT to add

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

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We use it to check conservation areas and constraints.
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    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 preliminary roost assessment by an accredited ecologist
    • A written report you can submit with your application
    • Advice on further surveys and their season
    • Mitigation measures drawn into your scheme where needed
    • Coordination with your planning drawings
    • Answers to the council's ecology questions
    Request your fixed quoteCall 020 7131 9703
    Architectural model of a four-storey London stucco townhouse in its terrace, with a portico, area railings, sash windows, a cornice and chimney stacks
    The house as it stands: four storeys over a lower ground floor.Existing Proposed worksAn illustrative model, built for this page.

    How we work on bat surveys

    Seven steps from first call to approval.

    The same model cut through the middle: every floor, the stair, the chimney breasts, the new mansard, rear extension and basement in section
    Section through the model: every floor on one datum.

    1. Enquiry and constraints check

      We check the property against conservation areas, listed status, Article 4 directions, tree preservation orders, flood zone and planning history. We choose the right route and send a fixed quote.

    2. Measured survey

      We survey the house on one datum: rooms, levels, boundaries, drains, trees and the neighbours' windows that the 45° and 25° tests depend on.

    3. Design options

      We model the house in Revit and show you options in 3D and plan, with the planning strategy and the precedents in your street.

    4. Design frozen

      You choose an option in writing. Nothing changes after this without your say.

    5. Independent check

      A second chartered technologist checks every sheet against the council's validation checklist and the policy. A senior review signs it off before anything is submitted.

    6. Submission

      We prepare the forms, certificates, fee and documents and submit through the Planning Portal.

    7. Officer liaison

      We answer the planning officer and make any amendments within five working days, at no charge until approval.

    Free redraws until approval. Every drawing set is checked independently, and the checker is never the person who drew it.

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    Why bats can stop a roof project

    The law is direct. Government guidance says "All bat species, their breeding sites and resting places are fully protected by law." The offence follows from it: under the Habitats Regulations, a person who "A person who damages or destroys a breeding site or resting place of a European protected species is guilty of an offence."

    That is why roof work is the usual trigger. A hip-to-gable, a dormer or a re-roof removes tiles, lifts felt and closes gaps, and any of those can destroy a place where bats rest. Even in a city, a gap under a ridge or behind a bargeboard may be enough.

    Georgian brick terrace with sash windows, arched fanlight doorways, stone steps and iron railings in London

    When the council will ask

    The planning guidance gives the signs it looks for: "Buildings with features suitable for bats, or large gardens in suburban and rural areas." In London that covers older terraces with loose tiles or timber soffits, buildings beside parks, canals or railway cuttings, and houses with large mature gardens.

    A loft conversion, a roof extension or demolition near any of these is a fair candidate. If you are unsure, our planning constraints report flags the site's nearby habitats and designations, and the ecologist confirms whether a survey is needed.

    What the assessment involves

    The first step is a preliminary roost assessment: a daytime inspection of the roof, loft and surrounding trees by a qualified ecologist, looking for droppings, staining, gaps and access points. The guidance gives its timing as "Any time of year (trees are best surveyed without foliage)."

    Most roofs finish there, with a report that says the building has low potential and the work can go ahead with sensible precautions. You need an expert, and the guidance says so: "You'll need an expert to do a bat survey."

    Where the inspection finds potential, further emergence surveys follow. Those depend on the season: summer roosts are surveyed from May to August, and hibernation roosts from November to mid-March. A site found in winter can lose months waiting, which is why we advise asking early.

    If bats are found

    It is not necessarily the end of the project. If harm cannot be avoided, the route is a licence: "If you cannot avoid harming bats or their habitats, you can apply for a mitigation licence from Natural England." The ecologist designs the mitigation, which may be as simple as a bat box or a bat access tile built into the new roof.

    We then draw that into the scheme. The measures sit on the planning drawings so the council sees one coherent design, and the same details carry through to the building regulations drawings for the builder.

    For landlords and investors

    A survey season missed can mean a stalled programme. If a roof or loft scheme is on your list, book the preliminary assessment when you exchange or as soon as the scheme is chosen, not when the application is ready.

    A feasibility study can run alongside it, so the layout is ready when the ecologist reports.

    The national rules in figures

    Figures with their unit, period and source
    MeasureValuePeriodSource
    GOV.UK bats guidance: legal protectionAll bat species, their breeding sites and resting places are fully protected by law—gov.uk
    Conservation of Habitats and Species Regulations 2017, regulation 43(1)(d): offenceA person who damages or destroys a breeding site or resting place of a European protected species is guilty of an offence—legislation.gov.uk
    Protected species and planning applications: habitat that calls for a surveyBuildings with features suitable for bats, or large gardens in suburban and rural areas—gov.uk
    Protected species and planning applications, survey timing table: preliminary roost assessmentAny time of year (trees are best surveyed without foliage)—gov.uk
    GOV.UK bats guidance: who surveysYou'll need an expert to do a bat survey—gov.uk
    Protected species and planning applications, survey timing table: summer roostsMay to August—gov.uk
    Protected species and planning applications, survey timing table: hibernation roostsNovember to mid-March—gov.uk
    GOV.UK bats guidance: if harm cannot be avoidedIf you cannot avoid harming bats or their habitats, you can apply for a mitigation licence from Natural England—gov.uk

    A blank value means the figure has not been published, not that there are none. Check your own address with the council.

    Which application your project needsLawful Development Certificate decision: 8 weeks. Prior approval decision: 42 days. Householder decision: 8 weeksYour projectWithin permitted development?Lawful Development CertificatePrior approvalHouseholder applicationYesLarger rear extensionNoABC

    Which application your project needs

    The usual route for a house; flats and listed buildings follow other rules.

    A · Lawful Development Certificate decision
    8 weeks
    B · Prior approval decision
    42 days
    C · Householder decision
    8 weeks

    What you receive

    Planning drawing sheet for a rear extension with plans, elevations and sections
    Sample drawing. Planning drawings for a rear extension: plans, elevations and sections on one sheet set.
    Brick cottage with a tiled roof, chimneys and a front dormer window
    The street around you
    Move across the plinth — the blocks rise around the pointer.

    Questions

    Do all roof projects need a bat survey?

    No. It depends on the building, its surroundings and the council's validation list. The ecologist can usually say after one inspection.

    Can I do the survey myself?

    Not for a planning application. The council expects a report by a qualified ecologist.

    Does a survey in winter count?

    A preliminary assessment can be done at any time of year. Emergence and activity surveys cannot, so a positive finding in winter may delay the next stage.

    Will the survey delay my application?

    Only if further surveys are needed. We arrange the first visit quickly so you know which case you are in.

    Sources and dates

    City of London skyline glowing at dusk across the Thames under a dramatic orange sky

    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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