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Islington, London

Flat conversion drawings in Islington

In Islington a house can only become flats if it is already big, and the mix of homes inside is capped as well. We prepare flat conversion drawings in Islington from £1,195 including VAT, as MCIAT chartered architectural technologists, and we check the size, the unit mix and the outdoor space against the Local Plan before a layout is drawn.

From £1,195 (VAT included)

  • MCIAT chartered
  • £2m PI insured
  • LABC Partnered
  • Fixed fees, VAT included

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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 flat conversion drawings

    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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    Red-brick mansion blocks and shopfronts on a street corner

    Islington's size threshold, mix limit and outdoor-space rule

    The Islington Local Plan: Strategic and Development Management Policies, Site Allocations, and Bunhill and Clerkenwell Area Action Plan sets two tests that matter more than any other. The first is size: 125 sqm GIA. In plain terms, a home is only considered for splitting when the existing dwelling exceeds that area, the new mix has no studios and no more than one one-bedroom unit.

    The second is outdoor space. The borough asks for private space of 5 sqm upper / 15 sqm ground, with extra for each additional occupant and a minimum depth and width of one and a half metres. Upper-floor flats usually meet it with a balcony or roof terrace, while the ground-floor flat is normally given the garden.

    These two rules decide which schemes are worth drawing. A mid-terrace house that barely clears the size threshold may be forced into a single large flat above a garden flat, whereas a wide corner house can sometimes take three. We measure the existing gross internal area first, then work out which mixes the unit rule leaves open. Our flat conversion drawings guide lists what the full set contains.

    Pencil resting on a dimensioned technical drawing beside a scale rule

    Local figures for Islington

    Figures with their unit, period and source
    MeasureValuePeriodSource
    Converting a home into more self-contained units is only permitted where the existing dwelling exceeds 125sqm GIA and the new mix has no studios and no more than one one-bedroom unit.125 sqm GIA—islington.gov.uk, Local Plan SDMP 2023, Policy H2, p.66, H2 G
    New homes and conversions must provide private outdoor space of at least 5sqm on upper floors and 15sqm on ground floors for 1-2 persons, plus 1sqm (upper) or 5sqm (ground) per extra occupant, with a minimum depth and width of 1.5 metres.5 sqm upper / 15 sqm ground—islington.gov.uk, Local Plan SDMP 2023, Policy H5, p.83, H5 D-E
    Minor application decisions675 decisions1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Minor applications granted86.5 %1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Minor applications decided in time96.7 % decided within 8 weeks or an agreed extended period1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder decisions337 decisions1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Households living in a house16.3 % of households living in a house or bungalow (detached, semi-detached or terraced)Census 2021nomisweb.co.uk
    Conservation areas41 named conservation areas published by the council—planning.data.gov.uk
    Listed building entries1,050 list entries (Historic England, within the LPA boundary)—planning.data.gov.uk
    Mayoral CIL charging band1 MCIL2 charging band (1-3)—london.gov.uk
    Mayoral CIL rate (indexed)96.97 £/m² (indexed, permissions granted in 2026)—london.gov.uk
    Borough CIL residential rate£300/m² (Zone A); £250/m² (Zone B) — residential dwellings, Use Classes C3 and C4schedule rate (approved 26 June 2014, effective 1 September 2014)islington.gov.uk
    Change of use of a building to one or more separate dwellinghouses, not more than 10: per dwellinghouse, from 1 Apr 2026610 GBP per dwelling—ribblevalley.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 Islington
    Building regulations, layer by layerPart A: structure: Approved Document A: Structure, 2004 edition incorporating 2004, 2010 and 2013 amendments. Part B: fire safety: All dwellings: fire detection and alarm system minimum Grade D2 Category LD3 (BS 5839-6), mains-operated smoke alarms to BS EN 14604. Part L: insulation: New elements in existing dwellings, limiting U-values W/(m²·K): roof 0.15, wall 0.18, floor 0.18, windows 1.4 (or WER Band B), doors 1.4. Part K: stairs: 2.0 m clear headroom over stairs. Full plans application: Building control body must decide a full plans application within 5 weeks, or longer if agreed in writingPart A: structurePart B: fire safetyPart L: insulationPart K: stairsFull plans applicationABCDE

    Building regulations, layer by layer

    The Approved Documents that shape most house projects, from structure to the application itself.

    A · Part A: structure
    Approved Document A: Structure, 2004 edition incorporating 2004, 2010 and 2013 amendments
    B · Part B: fire safety
    All dwellings: fire detection and alarm system minimum Grade D2 Category LD3 (BS 5839-6), mains-operated smoke alarms to BS EN 14604
    C · Part L: insulation
    New elements in existing dwellings, limiting U-values W/(m²·K): roof 0.15, wall 0.18, floor 0.18, windows 1.4 (or WER Band B), doors 1.4
    D · Part K: stairs
    2.0 m clear headroom over stairs
    E · Full plans application
    Building control body must decide a full plans application within 5 weeks, or longer if agreed in writing

    Why Islington sees more minor schemes than householder jobs

    Only 16.3 per cent of households in the borough live in a house or bungalow, and 26.7 per cent own their home. Houses are scarce, so every decision about one carries weight.

    The council's figures show it. In the latest twelve months it decided 675 minor applications, about twice its 337 householder decisions. It granted 86.5 per cent of the minor schemes, with 96.7 per cent decided in time.

    A high grant rate shows that well-prepared schemes can succeed. It also says that officers see plenty of conversions and recognise a thin one quickly, which is why we put the space schedule, mix statement and amenity plan into the first submission.

    Conservation, listing and basements

    Islington has 41 conservation areas and 1,050 listed building entries, and green belt covers 0 per cent of the borough, so the main heritage question is the front elevation. A second front door, a changed window pattern or a bin store at the frontage may need careful drawing in a conservation area.

    Design guidance sits in the Islington Urban Design Guide SPD, and a separate Basement Development SPD applies where a flat is to be gained below ground. Where a conversion would turn a lower-ground floor into a separate home, the basement guidance and the London Plan height test apply together.

    We read both documents against the address before suggesting a layout, so you know early whether a lower floor is a real option. The Islington area page lists the borough's wider constraints.

    Levy, fee and what a flat is worth here

    The Mayor's levy sits in band 1 here, the higher of the London charges, and the indexed rate this year is £96.97 per square metre. The borough levy is zoned and applies to homes in both Use Classes C3 and C4; the figures by zone are in the table. The small-scheme exemption does not apply where a new dwelling is created.

    The council charges £610 for each flat created. The average terraced house costs about £1,151,398 and a flat about £560,124, so the arithmetic of splitting a house is closer here than in outer boroughs.

    We set out levy and fee in the next-steps note. The later building regulations drawings turn an approved layout into technical sheets.

    What the Islington set contains

    Existing and proposed floor plans for each level, elevations, sections, a block plan and a schedule of areas by flat. If the flats will be sold separately, each needs its own lease plans. Neighbouring flat conversion drawings in Hackney show a different set of local limits.

    What you receive

    Building regulations section drawing showing the construction build-up
    Sample drawing. Building regulations section showing construction build-up for a building control check.
    Rear view of brick terraced houses in London with slate roofs and chimney stacks along the shared roofline
    Unit by unit
    Move up and down — the nearest units slide out.

    Other services in Islington

    Flat conversion drawings nearby

    Questions

    What size does a house need to be before Islington allows flats?

    The Local Plan only supports splitting where the existing dwelling exceeds 125 sqm GIA. We measure the house before design starts.

    Can an Islington conversion include a studio?

    No. The policy excludes studios from the new mix and allows no more than one one-bedroom flat.

    How much outdoor space must each flat have?

    The borough asks for 5 sqm upper / 15 sqm ground for one or two people, with a minimum depth and width of one and a half metres.

    Does the planning fee depend on the size of the flats?

    No. It is £610 for each flat created, paid to the council.

    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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