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Bexley, London

Building services design in Bexley

Bexley is mostly houses, and most of them are semis and terraces with a back garden and a loft worth using. We offer building services design for Bexley homes: the heating, hot water, ventilation, power and drainage worked out as one system, so the plant has a place on the plans before an extension is built around it. 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 building services design

    Four 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. Building regulations

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

    4. 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.

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    Brick house being extended, with a wide new opening supported over the ground floor

    What Bexley's application requirements say about services

    Bexley's Planning Application Requirements, an older document the council has not revised for several years, ask for two documents that sit on the services side. The Energy Assessment is the heavier one, and the council limits it to majors only. It follows the Mayor's energy hierarchy and gives priority to connecting a development to district heating, including the network around the Riverside Resource Recovery Facility.

    Below that sits a Sustainability Statement for non-major schemes that do not need a full assessment. The text asks for 10% renewables (20% encouraged) - dated, and it cites London Plan policies that have since been replaced. We treat the wording as a sign of what the case officer expects to see, and we write the statement against current policy, not the superseded references.

    For a householder extension neither document is normally triggered, so the requirement that matters is building control. Even then the council's thinking shows what a good services strategy contains: a fuel choice, an approach to ventilation and a short note on how the design reduces energy demand.

    Pencil resting on a dimensioned technical drawing beside a scale rule

    Local figures for Bexley

    Figures with their unit, period and source
    MeasureValuePeriodSource
    Energy Assessment required for major developments, following the GLA energy assessment guidance and the lean-clean-green hierarchy, with district heating connection (including the Riverside Resource Recovery Facility network) prioritised.majors only—bexley.gov.uk, London Borough of Bexley Planning Application Requirements (reviewed 17 October 2018), pp.15-16, 'Energy Assessment'
    Sustainability Statement is the lower tier: non-major developments that do not need a full Energy Assessment. Text states at least 10% of energy from renewables (20% encouraged), citing superseded London Plan 2016 policies.10% renewables (20% encouraged) - dated—bexley.gov.uk, London Borough of Bexley Planning Application Requirements (reviewed 17 October 2018), pp.26-27, 'Sustainability Statement'
    Households living in a house75.3 % of households living in a house or bungalow (detached, semi-detached or terraced)Census 2021nomisweb.co.uk
    Owner-occupied households68.6 % of households owner-occupied (owned outright or with mortgage/loan)Census 2021nomisweb.co.uk
    Domestic gardens share of land (GLUD 2005)25.1 % of land that is domestic garden (GLUD 2005)2005data.london.gov.uk
    Green Belt share of the council area17 % of council area covered by green-belt polygons—planning.data.gov.uk
    Conservation areas23 named conservation areas published by the council—planning.data.gov.uk
    Listed building entries114 list entries (Historic England, within the LPA boundary)—planning.data.gov.uk
    Registered parks and gardens4 registered parks and gardens intersecting the LPA boundary (Historic England)—planning.data.gov.uk
    Householder decisions877 decisions1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications granted94.6 %1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    Householder applications decided in time99.4 % decided within 8 weeks or an agreed extended period1 July 2025 - 30 June 2026assets.publishing.service.gov.uk
    AD L Vol 1 (2021 incl 2023) Table 4.1, PDF p.34; 2026 edition Table 3.10.26 W/(m2.K)—gov.uk
    AD L Vol 1 (2021 incl 2023) Table 4.1, PDF p.34; 2026 edition Table 3.10.16 W/(m2.K)—gov.uk
    AD L Vol 1 (2021 incl 2023) Table 4.3, PDF p.36; 2026 edition Table 3.30.7 W/(m2.K)—gov.uk
    Building Regulations 2010 reg.36(1)-(3); AD G (2015 incl 2016 and 2024 amendments) Requirement G2 and reg.36, PDF p.17125 litres per person per day—legislation.gov.uk
    Building Regulations 2010 reg.36(1)-(3); AD G (2015 incl 2016 and 2024 amendments) Requirement G2 and reg.36, PDF p.17110 litres per person per day—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 Bexley
    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 houses in Bexley need a services plan before an extension

    Some 75.3 per cent of Bexley households live in a house, and 68.6 per cent own their home. That mix suits rear extensions, lofts and garage conversions, and nearly all of them take a boiler, a cylinder or a consumer unit that was sized for the original house.

    The question we ask first is what the existing plant can carry. A combi boiler fed through a small gas meter will not serve a second bathroom and a utility room as well, and a thirty-year-old consumer unit may have no space for new circuits. Settling that on paper means the extension is drawn with a cupboard for the cylinder and a route for the pipes.

    Fabric comes first. For a new dwelling the limiting U-value of a wall is 0.26 W/m²K and of a roof 0.16 W/m²K. Where an existing wall is retained and altered, the trigger for improvement is 0.7 W/m²K, so an old solid wall is often caught by the upgrade rule.

    Water and air follow the same logic. A new bathroom needs a fan sized to the room, and the calculated water use of a new home is set against 125 litres per person per day, or 110 where the tighter option applies. We choose taps and showers from that budget and record the result for building control.

    Gardens, green belt and listed buildings

    Domestic gardens make up 25.1 per cent of the land in Bexley, and 17 per cent of the borough lies in green belt. A heat pump, an outbuilding supply or a ground-level plant enclosure is easy to place in a big garden, but near the green belt boundary it can raise extra questions.

    The council publishes 23 conservation areas, and Historic England records 114 listed building entries and 4 registered parks and gardens in the borough. Bexley also has an Article 4 direction on houses in multiple occupation, which affects how some larger houses can be used. We check each address before settling the position of flues, condensers and vents.

    The Design Guide SPD, Part 2, deals with alterations and extensions. The officer reading your drawings will test a heat pump or an extract terminal against its aims on bulk, neighbours and materials.

    What the Bexley services package includes

    You receive a short services strategy, a heat-loss summary, plant and riser positions drawn into the model, and coordination sheets showing the services against the structure. If you also want the layout sheets, our M&E drawings service adds them to the same set.

    In its latest year the council decided 877 householder applications, granted 94.6 per cent and decided 99.4 per cent in time. The services set sits beside our building regulations drawings in Bexley and the SAP calculations in Bexley that prove compliance. Borough context is on our page about architectural drawings in Bexley.

    We design and draw. A qualified installer fits and certifies the systems. Send us the plans and we will give a fixed quote after a free constraints check.

    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.
    Two-storey rear extension under construction on a semi-detached house
    Every layer specified
    Move across to open the layers; move down to pick one.

    Other services in Bexley

    Questions

    Does a Bexley extension need an energy assessment?

    The Energy Assessment is aimed at major developments. A householder extension normally meets building control through SAP or fabric checks, but a services strategy still decides whether the existing plant can cope.

    Can an extension in Bexley connect to district heating?

    The council's guidance gives district heating priority for major developments near a network. For a house it is rarely practical, so we usually design for a heat pump or an efficient boiler.

    What does building services design cost in Bexley?

    Fixed quote after a free constraints check. A single extension and a whole-house retrofit are far apart, so we price once we have seen your plans.

    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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