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Planning

Air quality assessment in London from £495

An air quality assessment shows your council whether the air at a site is fit for the people who will live there, and whether the scheme makes the air worse for anyone else. Our fee starts from £495, which buys a screening assessment for a small residential scheme; a larger job is confirmed in writing before you book. London councils ask for one when a site is in an Air Quality Management Area, when new homes sit beside a busy road, or when a scheme adds plant or boilers. A chartered architectural technologist (MCIAT) at Property Architecture carries it out.

From £495, no VAT to add

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

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    The fixed fee for air quality assessments

    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 the site against the council's Air Quality Management Area
    • Screening of nearby roads and background levels
    • An assessment written against the London Plan air quality policy
    • A clear statement of whether a detailed study is needed
    • Design measures to reduce exposure or emissions
    • A report written for the planning officer and environmental health team
    • Detailed modelling, if needed, confirmed in writing before you book
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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 air quality assessments

    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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    When a council asks for one

    The national planning guidance says It is important to take into account air quality management areas. Under the Environment Act 1995, where air quality standards or objectives are not being achieved, the local authority shall by order designate as an air quality management area. Your council publishes the boundary of each one it has declared.

    A site inside such an area is the commonest trigger. The second is a sensitive use: Air quality may also be a material consideration if the proposed development would be particularly sensitive, and a row of new flats beside a main road is the textbook case. The third is a scheme that adds emissions of its own, such as a gas boiler plant room, a combined heat and power unit, a generator or a car park.

    A small extension to an existing house rarely needs one. A new build, a change of use to residential or a block of flats often does. The planning officer or the borough's environmental health team will usually say so when they first respond.

    Rows of brick terraced houses and gardens on a residential street

    What the London Plan requires

    The London Plan's air quality policy states that development proposals must be at least Air Quality Neutral. Proposals should not lead to further deterioration of existing poor air quality. For larger schemes it adds that major development proposals must be submitted with an Air Quality Assessment.

    Where a site is in an Air Quality Focus Area, or will house people vulnerable to poor air, the policy asks that development proposals in Air Quality Focus Areas or that are likely to be used by large numbers of people particularly vulnerable to poor air quality, such as children or older people should demonstrate that design measures have been used to minimise exposure. Building work has its own duty: schemes must demonstrate how they plan to comply with the Non-Road Mobile Machinery Low Emission Zone and reduce emissions from the demolition and construction of buildings. We write the assessment against these parts of the policy and name the ones that apply to your scheme.

    Screening or a detailed assessment

    The government guidance says an assessment should include a description of baseline conditions and any air quality concerns affecting the area, and that Assessments need to be proportionate to the nature and scale of development proposed. We read that as a two-step job.

    Screening comes first. We check the site against the council's Air Quality Management Area map, the nearest roads and the published background levels, and set out in a short report whether there is a real concern. For many small schemes that is enough, and the council accepts it.

    A detailed assessment follows only when screening finds a concern, or the council asks for it in writing. It models the likely pollutant levels at the new homes' facades and gardens, or the effect of new emissions on neighbours, and sets out the measures that bring the scheme within the policy. We tell you which of the two your site needs before you commit to the larger piece of work.

    How design answers an air quality problem

    Design is the first lever to pull, and it is easier to use at the drawing stage than to retrofit. Moving bedrooms and openable windows to the quiet side of a block, setting buildings back from the kerb, using a mechanical ventilation intake on the cleaner elevation, and replacing gas plant with electric heating all reduce either exposure or emissions.

    That is why we read the assessment alongside your new build drawings and your energy statement, because the heating choice in one decides the emissions in the other. The report sits with our other specialist assessments in one submission.

    What we need from you and what happens next

    Send the address, a location plan, the proposed plans and the heating and ventilation intention, if known. Tell us the council and any planning reference. If the officer has asked for the assessment in an email, forward it.

    We confirm the scope in writing and tell you whether screening alone is likely to be enough. If your site needs detailed modelling, that goes beyond the from fee and we give you the figure in writing before you book. The finished report is written for the officer and the environmental health team, with the policy tests set out clearly.

    The national rules in figures

    Figures with their unit, period and source
    MeasureValuePeriodSource
    London Plan 2021, Policy SI 1 Improving air quality, part B2(a)development proposals must be at least Air Quality Neutral—london.gov.uk
    London Plan 2021, Policy SI 1, part B2(c)major development proposals must be submitted with an Air Quality Assessment—london.gov.uk
    London Plan 2021, Policy SI 1, part B1(a): development proposals should not do thislead to further deterioration of existing poor air quality—london.gov.uk
    London Plan 2021, Policy SI 1, part B2(d)development proposals in Air Quality Focus Areas or that are likely to be used by large numbers of people particularly vulnerable to poor air quality, such as children or older people should demonstrate that design measures have been used to minimise exposure—london.gov.uk
    London Plan 2021, Policy SI 1, part D: construction and demolition phasedemonstrate how they plan to comply with the Non-Road Mobile Machinery Low Emission Zone and reduce emissions from the demolition and construction of buildings—london.gov.uk
    Environment Act 1995, section 83(1): the duty when air quality standards or objectives are not being achievedthe local authority shall by order designate as an air quality management area—legislation.gov.uk
    PPG Air quality, paragraph 002It is important to take into account air quality management areas—gov.uk
    PPG Air quality, paragraph 004: new homes and other sensitive usesAir quality may also be a material consideration if the proposed development would be particularly sensitive—gov.uk

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

    Air quality assessments: the fee in writing before you commit

    From £495, no VAT to add. Send the address and anything you already hold, and we confirm the fixed fee in writing before any work starts.

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    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.
    Georgian brick terrace with sash windows, arched fanlight doorways, stone steps and iron railings in London
    The street around you
    Move across the plinth — the blocks rise around the pointer.

    Questions

    Does every London home extension need an air quality assessment?

    No. A small extension to an existing house rarely does. New homes, a change of use or a scheme with plant or boilers are the usual cases, and the council tells you when it wants one.

    What is an Air Quality Management Area?

    An area a council designates under the Environment Act 1995 when air quality standards or objectives are not being achieved. Your council publishes a map, and we check your site against it.

    What does air quality neutral mean?

    It is the London Plan's test that a scheme's emissions stay within the Mayor's published benchmarks. The assessment shows how your scheme meets it, and what on-site measures are needed if it does not.

    What is the difference between screening and a detailed assessment?

    Screening checks on paper whether there is a concern. A detailed assessment models pollutant levels. Many small schemes need only screening.

    How much does an air quality assessment cost?

    It starts from £495 for a screening assessment of a small residential scheme. A detailed study is a bigger job, so we confirm that figure in writing before you book. Send the address and the proposal.

    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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