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Croydon, London

Biodiversity net gain plans in Croydon

Croydon's validation list asks every applicant to say whether biodiversity net gain applies, exemptions included. It also sets a local trigger: a scheme affecting more than a stated area of vegetation needs an assessment. The council's recorded rule is 25 sq m vegetation trigger; statutory 10%. We prepare the statement or the full plan on a fixed quote after a free constraints check.

Fixed quote after a free constraints check

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    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 biodiversity net gain plans

    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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    Brick cottage with a tiled roof, chimneys and a front dormer window

    What Croydon's validation list says about net gain

    Croydon's local validation list, in its May edition, sets out three tiers. Every application must explain whether it is exempt from net gain. A non-exempt application needs a statement from a suitably qualified ecologist, with a plan of the on-site habitats and a copy of the baseline statutory metric. And a proposal affecting more than a set area of vegetation, on or next to the site, needs a fuller assessment. The council records this as 25 sq m vegetation trigger; statutory 10%.

    The first tier is the one most owners meet. Even a loft conversion application must carry a short statement saying why the condition does not apply. We write that statement as standard, with the correct exemption cited, so an otherwise sound application is not returned at the validation desk.

    The vegetation trigger is the surprise. It is measured on or adjacent to the site, so a hedge on the neighbour's boundary that your works would disturb can count. We check it on the survey and tell you before you commit to a design.

    Taken together, the three tiers reward early work. An applicant who has the survey, the exemption wording and the habitat plan ready at submission passes validation the first time, and the officer reads a coherent file. One who files the form first and sorts the rest later risks a returned application, and the delay is time a building programme rarely has.

    Rear view of brick terraced houses in London with slate roofs and chimney stacks along the shared roofline

    Local figures for Croydon

    Figures with their unit, period and source
    MeasureValuePeriodSource
    All applications must explain whether they are exempt from BNG; non-exempt applications need a BNG Statement from a suitably qualified ecologist with a plan of on-site habitats and a copy of the Statutory Metric (baseline). Proposals affecting more than 25 sq m of vegetation on or adjacent to the site need a BNG Assessment. No uplift above the statutory 10% stated.25 sq m vegetation trigger; statutory 10%—croydon.gov.uk, Croydon Local Validation List (May 2026), PDF p.17 (printed 15), 'Biodiversity Net Gain (BNG) Statement'
    Domestic gardens share of land (GLUD 2005)32.8 % of land that is domestic garden (GLUD 2005)2005data.london.gov.uk
    Green Belt share of the council area25 % of council area covered by green-belt polygons—planning.data.gov.uk
    Households living in a house60.2 % of households living in a house or bungalow (detached, semi-detached or terraced)Census 2021nomisweb.co.uk
    Conservation areas19 named conservation areas published by the council—planning.data.gov.uk
    Householder applications granted86.6 %1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Local plan adopted2,018—croydon.gov.uk
    Environment Act 2021 Sch 14 para 2, inserting Sch 7A TCPA 1990: 'relevant percentage' 10%10 %—legislation.gov.uk
    'Developments of 0.2 hectares or below': from 6 August 2026 BNG does not apply where the site area within the red line boundary is 0.2 ha or below0.2 ha—gov.uk
    'Developments subject to the de minimis rule': impact on less than 25 m2 (5 m by 5 m) of on-site habitat25 m2—gov.uk

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

    Councils bordering Croydon
    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

    Croydon's gardens and Green Belt

    Domestic gardens are 32.8 per cent of Croydon's land, and 60.2 per cent of households live in a house or bungalow. A further 25 per cent of the borough is Green Belt.

    The result is a borough with many large suburban plots. A rear garden of that size can hold substantial lawn, shrub and mature trees, which gives a new house a meaningful baseline. The design question is how to place the building so that the best of that habitat survives.

    Mature garden trees deserve a note of their own. In the metric a large, healthy tree is worth a great deal, and replacing it takes many young trees or a long wait. Where we can, we shift the footprint instead, and the drawings show the chosen position and the reason for it.

    Policy context and design guidance

    The borough's planning framework is the Croydon Local Plan 2018, adopted in 2,018, and its guidance includes the Conservation Areas General Guidance SPD. Croydon has 19 conservation areas, so a number of plots face both a design constraint and a habitat question.

    The conservation area guidance matters because it fixes the retained boundary treatment, such as hedges and front gardens, which are habitat too. We read it with the metric so the planting we propose is acceptable to both teams. Croydon also applies an Article 4 direction to houses in multiple occupation, which is a separate matter from habitat but often arrives in the same scheme.

    For a new dwelling, our new build drawings include the landscape layout the plan relies on.

    Who needs the full plan

    Householder applications and permitted development are exempt, though the form must say so. Sites of 0.2 hectares or below are exempt, and impacts below 25 square metres of habitat are excluded under the de minimis rule.

    Croydon decided 94.4 per cent of householder applications in time and granted 86.6 per cent of them in the latest returns. That makes an invalid form an avoidable cost, and it is why we complete the exemption statement for every application we submit.

    Price and next step

    A statement or plan has no list price. You receive a fixed quote after a free constraints check, which includes the exemption wording for the form where it applies.

    Read the national rules on our biodiversity net gain page or see every service on the Croydon area page.

    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.
    Pencil resting on a dimensioned technical drawing beside a scale rule
    The street around you
    Move across the plinth — the blocks rise around the pointer.

    Other services in Croydon

    Biodiversity net gain plans nearby

    Questions

    Does Croydon require a statement even when my project is exempt?

    Yes. The validation list asks every application to explain whether it is exempt from net gain.

    What is the vegetation trigger?

    The council's recorded rule is 25 sq m vegetation trigger; statutory 10%: a proposal affecting more than that area of vegetation on or next to the site needs an assessment.

    Does a neighbour's hedge count?

    It can, because the trigger covers vegetation adjacent to the site as well as on it.

    How long is the gain kept?

    At least 30 years after completion.

    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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