020 7864 7245Request a fixed quote

Ealing, London

SAP calculations in Ealing

If you are extending or building a home in Ealing, a SAP calculation shows building control that the design meets Part L, and we coordinate it with an assessor from your drawings for a fixed quote after a free constraints check, VAT included. Ealing holds 31 conservation areas and 309 listed entries, which is why we settle the external materials before the energy figures.

Fixed quote after a free constraints check

  • 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 sap calculations

    Five 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. 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.

    4. Building regulations

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

    5. 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
    Red-brick English house with rows of solar panels on its tiled roof

    SAP calculations in Ealing and the residential extensions SPD

    Ealing has no energy rule of its own for house extensions. The council's design guidance is the thing that bites, and its SPD 4 - Residential extensions sets the proportions of a rear or side addition. A design that follows it tends to be a modest masonry box, which is the easiest kind to pass on simple limits.

    The trouble starts when owners want more glass than the guidance comfortably allows. A large glazed rear wall can satisfy the planners and still fail the energy glazing cap. We check the two against each other on one drawing, so a door width agreed for planning does not later cost a redesign for Part L.

    House extension under construction with scaffolding, new glazed doors and building materials

    Local figures for Ealing

    Figures with their unit, period and source
    MeasureValuePeriodSource
    Conservation areas31 named conservation areas published by the council—planning.data.gov.uk
    Listed building entries309 list entries (Historic England, within the LPA boundary)—planning.data.gov.uk
    Grade II* listed entries18 list entries—planning.data.gov.uk
    Households living in a house50.3 % of households living in a house or bungalow (detached, semi-detached or terraced)Census 2021nomisweb.co.uk
    Average price, terraced711,468 GBP2026-07publicdata.landregistry.gov.uk
    Average price, detached1,411,890 GBP2026-07publicdata.landregistry.gov.uk
    Approved Document L Vol 1 2021 incl. 2023 amendments, Table 4.2New 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—gov.uk
    Approved Document L Vol 1 2021, para 10.7(d)Windows, roof windows, rooflights and doors in an extension should not exceed 25% of the extension floor area plus the area of openings removed or covered—gov.uk
    Building Regulations 2010 notices referencing reg 7A of the Energy Performance of Buildings (England and Wales) Regulations 2012An energy performance certificate is required on construction of a new dwelling—legislation.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 Ealing
    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

    Garden suburbs and conservation areas across Ealing

    Alongside its 31 conservation areas, Ealing has buildings on the national list: Historic England records 309 entries in the borough. Of those, 18 are Grade II* listed, the tier just below the most important buildings in the country.

    For a house in one of these places the calculation has to reflect what the council will let you build. Replacement windows in a protected frontage may be limited to a slim double-glazed unit, which affects the window U-value. External wall insulation that changes a brick face may be resisted, so internal lining or a cavity fill carries the load. We record those decisions in the specification before the assessor models anything.

    What an Ealing home is worth, and what it can afford

    Ealing is a borough of high values. A terraced house sold for about £711,468 on average and a detached house for £1,411,890 in the latest Land Registry data. Only 50.3 per cent of households live in a house, so roughly half of Ealing homes are flats, where the energy rules apply to each new dwelling rather than to a house extension.

    At those values, a heat-pump-ready specification or triple glazing is a fair investment, and the SAP route lets the designer trade it against a larger rear opening. The elemental route is simpler; the trade route is more generous. When the numbers are close, we ask the assessor to model both.

    The numbers an extension has to meet

    New elements in an existing home are held to these limits: 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. Everything on the drawing, from the roof build-up to the floor insulation under the slab, is set against them.

    The glazing limit is separate: Windows, roof windows, rooflights and doors in an extension should not exceed 25% of the extension floor area plus the area of openings removed or covered. Where a bi-fold or a roof lantern pushes the area over, the compliance route changes: Alternative routes: area-weighted U-value (para 10.9) or a SAP calculation against a notional extension (para 10.10).

    Our house extension drawings include a glazing count on the plan, so the energy question is answered while the layout can still move.

    New homes and conversions in Ealing

    A new dwelling is judged on a whole-building basis. For new dwellings AD L 2026 names two methods: the Home Energy Model (HEM) and SAP; validity dates are in the Notice of Approval. Whichever applies on your deposit date, the assessor needs final floor areas, heating type and window schedule, all of which come from the same model that produces your plans.

    A finished home also needs a certificate. The rule is plain: An energy performance certificate is required on construction of a new dwelling. We keep the specification on the construction drawings, so what is built matches what was predicted.

    What building control in Ealing will ask to see

    Whatever route you choose, building control will want the evidence on paper at the start, not at completion. For a simple-limits extension that is a specification sheet naming each element and its U-value. For a SAP route it is the full report and the drawing set it was built from.

    Some Ealing projects combine more than one piece of work, such as a rear extension with a loft above. We treat those as one energy picture, because the new roof and the new walls share the same airtightness and heating strategy, and doing them separately can leave a gap in the paperwork.

    Building control may ask for photographs of insulation going in during the build. We tell the builder which stages to photograph, and we list them on the drawing notes so nobody has to remember.

    Next steps for an Ealing project

    Read the wider picture on our page for architectural drawings in Ealing, then see the construction side under building regulations drawings in Ealing. When the beams are sized, structural calculations in Ealing follow the same set.

    We quote the energy work as a fixed sum after a free constraints check, VAT included, because the scale of the job decides the price. Send the address and the brief.

    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.
    Pencil resting on a dimensioned technical drawing beside a scale rule
    Energy in
    Move the pointer up — the plug rises toward the socket.

    Other services in Ealing

    SAP calculations nearby

    Questions

    Does Ealing require a SAP calculation for a rear extension?

    Not by itself. Building control accepts the elemental route, an area-weighted U-value calculation or a SAP calculation, as the guidance describes: Alternative routes: area-weighted U-value (para 10.9) or a SAP calculation against a notional extension (para 10.10).

    How do Ealing conservation areas affect energy compliance?

    Ealing has 31 conservation areas. Where the council restricts external changes, insulation and windows have to be chosen to suit, and the calculation uses those choices.

    What is the glazing limit on an extension?

    Windows, roof windows, rooflights and doors in an extension should not exceed 25% of the extension floor area plus the area of openings removed or covered.

    How is the SAP calculation priced in Ealing?

    Fixed quote after a free constraints check, VAT included.

    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