House Extensions · SE3 Blackheath
Fixed-fee house extension drawings for Blackheath, Blackheath Village, Kidbrooke, Westcombe Park fringe in the SE3 postcode, drawn by an MCIAT-chartered architectural technologist and submitted to Greenwich Council. Greenwich controls the Blackheath and Cator Estate conservation areas; the post-war Span estates also carry conservation protection.
MCIAT chartered drawings for planning, building regs, lofts and extensions — fixed fees 30% below typical London architects. Tell us what you need and we’ll reply the same working day.
House extensions in Blackheath are dominated by single-storey rear and side-return additions on SE3's georgian and victorian houses around blackheath, large, with double-storey and wrap-around schemes where the plot allows. Greenwich Council weighs depth, height and neighbour daylight; many extensions across Blackheath, Blackheath Village, Kidbrooke, Westcombe Park fringe are Permitted Development, which we confirm with a Lawful Development Certificate before you build.
The whole spectrum — rear extensions, side returns, wraparounds, double-storey, basement digs. Planning-led design with detailed technical phase, ideal for georgian and victorian houses around blackheath, large typical of Blackheath.
Across Blackheath, Blackheath Village, Kidbrooke, Westcombe Park fringe in SE3, the dominant property is georgian and victorian houses around blackheath, large detached and semi-detached villas, and the modernist span estates of kidbrooke. That stock shapes what house extension drawings looks like here: the right approach for a period terrace differs from a mansion-block flat or a new-build, and Greenwich Council judges each on design quality and neighbour impact. We survey the specific Blackheath property, confirm the planning route — Permitted Development, a Lawful Development Certificate, or full planning — and draw a council-ready set tailored to the SE3 streetscape.
Housing stock in SE3: Georgian and Victorian houses around Blackheath, large detached and semi-detached villas, and the modernist Span estates of Kidbrooke.
Within the district: Blackheath, Blackheath Village, Kidbrooke, Westcombe Park fringe.
Streets we know in SE3: the Cator Estate roads, Blackheath Park, Montpelier Row and the Span estates off Foxes Dale. Each road has its own building line, boundary treatment and precedent that Greenwich Council weighs when assessing a house extension drawings scheme.
Conservation areas: Blackheath Park (Cator Estate), Blackheath Village, Westcombe Park. Inside these, most external work needs full planning and a Heritage Statement.
Getting around SE3: Blackheath and Kidbrooke rail to London Bridge, Cannon Street and Victoria.
Regeneration: Blackheath falls within or beside the Kidbrooke Village (one of London's largest estate regenerations), which shapes local planning policy and design expectations.
Property values: around £450,000 for a flat and £900,000-£1.6m for a house — a useful gauge of the build value an extension or loft adds in SE3.
Borough character: World Heritage Site status in Greenwich town centre adds heritage weight; outer borough areas (Eltham, Thamesmead) generally permissive.
Measured existing survey, photographic record, Article 4 and conservation check specific to Blackheath before we quote.
2–3 design options at concept stage — alternative layouts, glazing, roof forms.
Site location plan, existing and proposed plans, elevations, sections, D&AS where required.
Part L thermal, Part B fire, Part M accessibility, structural strategy.
Steel beam, foundation, lintel design. Chartered engineer sign-off.
Party Wall notices where needed; Thames Water Build Over Agreement where within 3m of a public sewer.
Single planning or building-regs submission.
Planning + building regs + structural.
Listed, conservation or complex sites.
Strongly. The Blackheath, Blackheath Park (Cator Estate) and Westcombe Park conservation areas mean full planning with a Heritage Statement for external changes, and Greenwich scrutinises materials, boundaries and roofscape closely. We design to that standard for the Georgian and Victorian houses around the heath.
It needs care. The modernist Span estates off Foxes Dale are conservation areas with strong design controls and residents' covenants protecting their original character, so even windows and finishes are controlled. We design sympathetically to the Span aesthetic and handle both the planning and any management-company consent.
Kidbrooke Village is one of London's largest estate regenerations — thousands of new homes, a new station forecourt and parkland — lifting values across SE3. For an individual house project the binding controls remain Permitted Development limits and the local conservation designation, which we check for your address.
Outside the conservation areas, usually yes — a rear dormer or hip-to-gable within the volume allowance, confirmed by a Lawful Development Certificate. Inside the Blackheath or Cator Estate designations, roof changes need full planning and are assessed on their impact on the historic roofscape. We confirm which applies to your road.
Our fixed fee for house extension drawings in Blackheath starts at £1,225 — no hourly billing. With Blackheath property at around £450,000 for a flat and £900,000-£1.6m for a house, the professional drawing fee is a small fraction of the value the work adds to SE3's georgian and victorian houses around blackheath, large. Greenwich Council charges its own statutory application fee on top (currently £258 for a householder planning application, £578 for a full application). We quote the drawings as one fixed price and the free site survey covers every SE3 address.
For a SE3 project across Blackheath, Blackheath Village, Kidbrooke, Westcombe Park fringe, expect roughly 3–4 weeks from instruction to submission: week 1 the measured survey, weeks 2–3 the drawings and your revisions, then validation and the statutory determination by Greenwich Council (8 weeks for a householder application). We carry the Blackheath application through every officer query to the decision.
Blackheath (SE3) sits primarily in Greenwich, so applications are decided by Greenwich Council. Article 4 in force in the borough: No. Conservation areas within SE3 include Blackheath Park (Cator Estate), Blackheath Village, Westcombe Park, where full planning and a Heritage Statement are required. We confirm the planning route for your exact address before quoting.
Almost always. Any structural work behind house extension drawings in Blackheath — new openings, steel beams, loft floors, foundations — needs Building Regulations approval covering structure (Part A), fire escape (Part B) and insulation (Part L), submitted to Greenwich Council Building Control or an approved inspector. On SE3's typically terraced and semi-detached stock, a Party Wall notice to adjoining neighbours is normally required before the steelwork. We coordinate both as part of the Complete package.
In value terms, yes. With Blackheath (SE3) property at around £450,000 for a flat and £900,000-£1.6m for a house, a well-designed extension or loft typically returns more than it costs in added floor area and sale value, while our fixed drawing fee from £1,225 keeps the professional cost predictable. The bigger risk is an unapproved or non-compliant scheme — which is why council-ready drawings and a clean Building Control sign-off matter on SE3 homes.
From £840.
From £840.
From £1,225.
From £1,575.
From £995.
From £1,950.
From £350.
From £540.
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From £1,225.
Pick a slot that suits you. No obligation and no sales pressure — just straight answers on your planning route, fixed fee and timescale.
Every SE3 postcode district we draw in, the stock that dominates it and the authority that validates a house extension there. SE3 fees below are the statutory England rates for 2026, not house extension estimates.
| Postcode | Area | Dominant stock | What it means for a house extension |
|---|---|---|---|
| SE3 | Blackheath / Kidbrooke | Georgian villas, Victorian terraces | A house extension in Blackheath / Kidbrooke may land with Greenwich Council or Lewisham Council — SE3 crosses the boundary, and the SE3 policies map decides it street by street. |
| SE3 | Blackheath (Greenwich) | Georgian villas, Victorian terraces | Blackheath (Greenwich) sits inside SE3; house extension proposals here are determined by Greenwich Council. |
| SE3 | Kidbrooke | New-build, post-war fragments | Kidbrooke sits inside SE3; house extension proposals here are determined by Greenwich Council. |
| SE3 | Blackheath | Georgian villas, Victorian terraces | Blackheath sits inside SE3; house extension proposals here are determined by Lewisham Council. |
| SE2 | Abbey Wood | mixed stock | Adjoining district to SE3, also inside Greenwich for house extension purposes. |
| SE7 | Charlton | Victorian villas, 1930s semi-detached | Adjoining district to SE3, also inside Greenwich for house extension purposes. |
| SE9 | Eltham / Mottingham | 1930s semi-detached, post-war flats | Adjoining district to SE3, also inside Greenwich for house extension purposes. |
| SE4 | Brockley | Victorian and Edwardian terraces | Adjoining district to SE3, also inside Lewisham for house extension purposes. |
| SE6 | Catford / Bellingham | 1930s semi-detached, post-war flats | Adjoining district to SE3, also inside Lewisham for house extension purposes. |
| SE8 | Deptford | Georgian terraces, post-war estates, new-build | Adjoining district to SE3, also inside Lewisham for house extension purposes. |
| SE12 | Lee / Grove Park | mixed stock | Adjoining district to SE3, also inside Lewisham for house extension purposes. |
Roof pitch, wall build-up and plot depth change every few SE3 streets, and each one changes what a house extension can achieve at that address.
SE3 (Blackheath / Kidbrooke) conservation designations: there are 20 across Greenwich Council, Blackheath, Charlton, Eltham Park among them. Designation costs a SE3 (Blackheath / Kidbrooke) owner the permitted-development route: a house extension then needs a £258 householder application over 8 weeks, in place of the £120 prior approval route that takes 6 weeks. Charlton is the SE3 (Blackheath / Kidbrooke) designation that most often changes a house extension design.
Article 4 and your SE3 (Blackheath / Kidbrooke) house extension: Greenwich Council has made no borough-wide direction, so permitted development for a house extension in SE3 (Blackheath / Kidbrooke) generally survives outside SE3 (Blackheath / Kidbrooke) conservation areas and listed curtilages. A Lawful Development Certificate at £129 is how a SE3 owner records that a house extension was lawful.
What SE3 (Blackheath / Kidbrooke) is built from: Georgian in Greenwich town centre; Victorian terraces in East Greenwich, Charlton; inter-war semi-detached in Eltham; new-build along the riverside. World Heritage Site status in Greenwich town centre adds heritage weight; outer borough areas (Eltham, Thamesmead) generally permissive. That mix decides the house extension route in SE3 (Blackheath / Kidbrooke) more than the postcode does. Our fixed fee for house extensions in SE3 (Blackheath / Kidbrooke) starts at £1,225, against £1,750 for the Complete package that carries a SE3 (Blackheath / Kidbrooke) scheme through Greenwich Council planning and building regulations together.
SE3 (Blackheath / Kidbrooke) conservation designations: there are 30 across Lewisham Council, Deptford High Street, Forest Hill, Hither Green among them. Designation costs a SE3 (Blackheath / Kidbrooke) owner the permitted-development route: a house extension then needs a £258 householder application over 8 weeks, in place of the £120 prior approval route that takes 6 weeks. Forest Hill is the SE3 (Blackheath / Kidbrooke) designation that most often changes a house extension design.
Article 4 and your SE3 (Blackheath / Kidbrooke) house extension: Lewisham Council has made no borough-wide direction, so permitted development for a house extension in SE3 (Blackheath / Kidbrooke) generally survives outside SE3 (Blackheath / Kidbrooke) conservation areas and listed curtilages. A Lawful Development Certificate at £129 is how a SE3 owner records that a house extension was lawful.
What SE3 (Blackheath / Kidbrooke) is built from: Victorian and Edwardian terraces across Brockley, Honor Oak, Forest Hill; 1930s semi-detached in Catford and Hither Green; post-war mixed in Deptford. Generally permissive planning compared to central boroughs; loft conversions and side-return extensions routinely approved under PD. That mix decides the house extension route in SE3 (Blackheath / Kidbrooke) more than the postcode does. Our fixed fee for house extensions in SE3 (Blackheath / Kidbrooke) starts at £1,225, against £1,750 for the Complete package that carries a SE3 (Blackheath / Kidbrooke) scheme through Lewisham Council planning and building regulations together.
Sources for this SE3 house extension page: borough policies maps and conservation-area registers (2025–26), Royal Mail postcode district boundaries, the Town and Country Planning (Fees for Applications) (England) Regulations, the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended, and the Party Wall etc. Act 1996.
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