020 7864 7245Request a fixed quote

Hillingdon, London

Loft conversion drawings in Hillingdon

Hillingdon has 150 Article 4 directions and 731 tree preservation orders, so a loft here starts with paperwork before pencil. Our loft conversion drawings begin at £695 including VAT and with houses at 68.9 per cent of households, demand is steady.

From £695 (VAT included)

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

Request a fixed quote

We use it to check conservation areas and constraints.
Pick the council that decides your application.
A few lines: what you want to build, and anything the council has already said.
Add photos or drawings

Drop files here or choose from your device

PDF, JPG, PNG, DWG · up to 10 files, 90 MB in total

    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 loft conversion drawings

    Nine 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.

    8. Building regulations

      Technical drawings are coordinated with the structural engineer's calculations, the drainage and the planning conditions.

    9. Approval and hand-over

      Building control approval, then a next-steps pack covering the commencement notice, party wall timing and CIL.

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

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

    Article 4 directions in Hillingdon

    The council publishes 150 Article 4 directions. Each controls specified works in a defined area and the notice names them, so a street may lose rights to alter front elevations but keep the rear roof, or the reverse. We read the notice for your address and note which classes of work it covers.

    Where a direction removes roof rights, the loft is drawn as a planning application. Where it does not, the scheme can follow the national limits and be certified. Because the number of directions is high, we make this the very first check on every Hillingdon job.

    The Hillingdon Local Plan Part 1: Strategic Policies, with Local Plan Part 2: Development Management Policies and Site Allocations and Designations (January 2020) sets the wider framework, and officers read a loft against it and against the appearance of the street.

    Many Hillingdon homes are suburban houses from the interwar and postwar periods, and plenty of owners have already extended at the back. A loft is the next step, and the previous works matter: any earlier rear roof additions count towards the volume allowance, so we ask for earlier drawings and measure what exists.

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

    Local figures for Hillingdon

    Figures with their unit, period and source
    MeasureValuePeriodSource
    Conservation areas33 named conservation areas published by the council—planning.data.gov.uk
    Article 4 directions150 Article 4 directions published by the council—planning.data.gov.uk
    Tree preservation orders731 tree preservation orders published by the council—planning.data.gov.uk
    Green Belt share of the council area42 % of council area covered by green-belt polygons—planning.data.gov.uk
    Listed building entries436 list entries (Historic England, within the LPA boundary)—planning.data.gov.uk
    Households living in a house68.9 % of households living in a house or bungalow (detached, semi-detached or terraced)Census 2021nomisweb.co.uk
    Lawful development certificate applications (PS1)529 certificates2025 Q2 to 2026 Q1 (1 Apr 2025 to 31 Mar 2026)assets.publishing.service.gov.uk
    Householder decisions1,147 decisions1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications granted90.2 %1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications decided in time94.3 % decided within 8 weeks or an agreed extended period1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Approved Document K 2013, para 1.13, Diagram 1.4Loft conversions where 2.0 m cannot be achieved: 1.9 m at the centre of the stair, 1.8 m at the side (half width)—gov.uk
    Approved Document B Vol 1, para 2.21New storey above 4.5 m by loft conversion: protect the full escape route with fire-resisting doors (min E 20) and partitions (min REI 30)—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 Hillingdon
    Loft enlargement in section: the permitted development limitsExtra roof volume allowed: 40 m³ (terrace house) / 50 m³ (any other house) additional roof volume. Set-back from the eaves: Original eaves maintained; enlargement set at least 0.2 m from the eaves measured up the roof slope, so far as practicable (not required for hip-to-gable or roofs joining a rear/side extension). Height limit: No part higher than the highest part of the existing roofABC

    Loft enlargement in section: the permitted development limits

    A dormer on the rear slope, with the limits that decide whether it needs planning permission.

    A · Extra roof volume allowed
    40 m³ (terrace house) / 50 m³ (any other house) additional roof volume
    B · Set-back from the eaves
    Original eaves maintained; enlargement set at least 0.2 m from the eaves measured up the roof slope, so far as practicable (not required for hip-to-gable or roofs joining a rear/side extension)
    C · Height limit
    No part higher than the highest part of the existing roof

    Trees, Green Belt and listed buildings

    The borough has 731 tree preservation orders. A protected tree in a rear garden can limit scaffold access, restrict a build near its roots and, if branches overhang the roof, affect the daylight to a new dormer window. The survey records any tree near the house.

    Green Belt covers 42 per cent of the borough. As elsewhere, the national volume allowance for a loft within the roof is unaffected, but outbuildings and larger additions are tested more strictly. Historic England lists 436 entries in Hillingdon and the borough holds 33 conservation areas, including village centres where the roofscape matters.

    Roofs in older and rural parts of the borough are also the likeliest to contain bat roosts, which are legally protected. We flag any sign of them early.

    A mature oak or lime beside a rear elevation can change the whole plan, because a dormer window facing it may be shaded, and works near its roots can be restricted. We do not guess; we mark every protected tree on the block plan.

    What a Hillingdon loft must meet under building regulations

    A conversion needs a safe way out. Where the new storey sits above the height set out in Approved Document B, the escape route must be protected with fire-resisting doors and partitions, and the national figures for the stair headroom exception apply where full height cannot be reached. Smoke alarms are required throughout, and new roof elements must meet the current thermal limits.

    These details come from the national rules, not the council, but they determine the stair position and the shape of the landing, so they are drawn from the start. Our building regulations drawings in Hillingdon carry the same survey forward into the technical set.

    A designer cannot give structural advice, so we pass the drawn dimensions to an engineer who sizes the beams, the floor and the roof supports. The engineer's drawings and calculations then go into the building control submission alongside ours.

    How Hillingdon decides household applications

    The council has a large caseload: 1,147 householder decisions in the latest year. It granted 90.2 per cent, with 94.3 per cent decided in time. Those figures cover every kind of home project, so we use them to set timing expectations.

    The borough also dealt with 529 lawful development certificate applications, so owners are used to proving permitted development. Our page on a lawful development certificate in Hillingdon explains how the process works for a loft.

    Gardens cover 18.6 per cent of the borough in the Greater London survey, and owners value them. A loft keeps the garden whole. The average Hillingdon home sold for about 470,875 pounds in the latest figures, so the extra room is a sound investment.

    Drawings, price and neighbouring boroughs

    Each set holds existing and proposed floor plans, the stair, a roof section, elevations and the location and block plans. The price starts at £695 including VAT, with amendments after council comments included.

    If permission is needed, our planning drawings in Hillingdon cover the application. Next door, see Hounslow and Ealing, and for all our services in the borough, architectural drawings in Hillingdon.

    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.
    Slate-clad roof extension on a yellow-brick London terraced house
    Storey by storey
    Move up and down — the car travels between floors.

    Other services in Hillingdon

    Loft conversion drawings nearby

    Questions

    How many Article 4 directions does Hillingdon have?

    The council publishes 150. We read the notice for your street to see whether roof works are covered.

    Do tree preservation orders affect a loft?

    They can affect scaffold access and work near roots, so we record protected trees during the survey.

    What do Hillingdon loft drawings cost?

    From £695 including VAT, fixed before work begins.

    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.

    Request a fixed quoteCall 020 7864 7245WhatsApp