Sitting within the SE6 postcode in the London Borough of Lewisham, Catford has steadily grown in appeal among families and first-time buyers seeking genuine space and value in South East London. From the solid Victorian terraces lining Sangley Road and Handen Road, to the Edwardian semis surrounding Mountsfield Park and the well-kept period streets near Catford Bridge station, the area offers a quality and scale of housing that continues to attract homeowners looking to put down long-term roots.
For SE6 homeowners, extending rather than moving is the most practical and cost-effective route to gaining the space a growing household needs. Catford's property values have strengthened steadily, supported by improving local amenity, strong school catchments, and regular rail services into London Bridge and Charing Cross. A well-executed extension delivers a meaningful improvement to daily living and a reliable return at resale. This guide is written specifically for Catford homeowners and draws on Buildaway's experience delivering extensions across Lewisham, combining transparent 2026 pricing, local planning knowledge, and an 18-month labour warranty on every completed build.
How Much Does a House Extension Cost in Catford (2026)?
Catford sits in the mid range of South East London's construction market, offering competitive build costs that reflect the scale and character of SE6's Victorian and Edwardian housing stock. Below are realistic 2026 mid-market figures:
Single-Storey Rear Extension
- Build-only: £2,300 – £3,100 per m²
- Fully finished with kitchen: £3,100 – £4,300 per m²
- Example: 25 m² kitchen-diner = £57,500 – £77,500 build-only or £77,500 – £107,500 turnkey.
Double-Storey Rear Extension
- Build-only: £2,100 – £2,900 per m²
- Fully finished: £2,900 – £4,100 per m²
- Example: 40 m² across two floors = £84,000 – £116,000 build-only or £116,000 – £164,000 turnkey.
Side Return & Wrap-Around Extensions
A practical and popular choice for Catford's Victorian mid-terrace stock: £2,300 – £3,500 per m², depending on structural requirements, roof specification, and glazing choice.
All figures reflect fully compliant, Building Control certified builds meeting Lewisham Council's current planning and construction standards.
What Drives the Price Up or Down
- Total floor area — the primary cost variable across all project types; a larger footprint increases structural, insulation, and finishing expenditure proportionally.
- Structural steelwork — load-bearing wall removal is routine across Catford's Victorian and Edwardian terrace stock and typically adds £2,500–£6,500 to the overall project cost.
- Roof design and specification — flat roofs with quality membranes and rooflights are the most cost-effective solution; pitched or lantern roof designs add cost but significantly improve natural light in the extended space.
- Glazing and doors — bi-fold or sliding doors connecting the extended ground floor to a rear garden are popular across SE6 and add £3,500–£9,500 depending on opening width and frame specification.
- Conservation area obligations — parts of Catford, including streets within the Hither Green and Mountsfield conservation areas, are subject to Lewisham's heritage controls, influencing material choices and the design approach required for consent.
- Kitchen and bathroom fit-out — kitchens in the SE6 market typically range from £9,500 to £25,000+; bathrooms from £5,500 to £14,000.
- Heating and mechanical upgrades — Megaflo unvented systems or boiler replacements are commonly required when extensions add floor area or new bathrooms: £3,000–£5,500.
- Site access and logistics — controlled parking zones, the constraints of Catford's busier residential roads, and the density of SE6's housing all contribute to preliminary costs and require careful programme management.
Planning Permission & Building Control in Catford
- Permitted Development (PD): Smaller single-storey rear extensions in Catford may qualify under PD rights, provided they meet Lewisham's criteria for depth, height, and materials. Properties within conservation areas or those subject to Article 4 Directions require careful individual assessment before PD is assumed.
- Neighbour Consultation Scheme: Extensions beyond standard PD depth limits — up to 6 metres for terraced and semi-detached properties, 8 metres for detached — require formal notification to Lewisham Council and neighbouring owners before works begin. Buildaway manages this process on your behalf.
- Full Planning Permission: Required for double-storey extensions, proposals with street-facing visibility, front alterations, and all projects falling outside PD thresholds.
- Conservation Areas: The Hither Green and Mountsfield conservation areas, along with other designated zones within SE6, impose material and design controls on extensions. Lewisham's planning officers assess all proposals within these areas for visual compatibility with the original building and wider streetscape.
- Party Wall Act: The density of terraced and semi-detached housing throughout Catford means the Party Wall etc. Act 1996 applies to the majority of extension projects in SE6. Written notices must be formally served on all affected adjoining owners before any structural or excavation works commence.
- Building Control: Mandatory for all extension types — covering structural calculations, thermal performance, drainage, fire safety, and electrical compliance. Buildaway coordinates with Lewisham's building control team and accredited private inspectors as appropriate to each project.
How Long Will It Take?
- Design and planning preparation: 4–10 weeks
- Technical drawings, approvals, and statutory notices: 3–7 weeks
- On-site construction:
- Single-storey: 10–14 weeks
- Double-storey: 14–20 weeks
- Conservation area applications, bespoke glazing, or premium kitchen installations may extend the overall programme by two to four weeks.
Typical Full Project Budget Breakdown (30 m² Double-Storey)
| Element | Typical Cost |
|---|---|
| Core structure & shell | £66,000 – £84,000 |
| Windows / doors / glazing | £4,500 – £10,000 |
| Kitchen supply & fit | £9,500 – £23,000 |
| Bathroom fit-out | £5,500 – £13,000 |
| Heating / boiler / Megaflo | £3,000 – £5,500 |
| Flooring & decorating | £5,500 – £14,000 |
| Professional fees & permissions | £3,000 – £8,000 |
| Total realistic range: | £97,000 – £145,000 |
(Higher-specification finishes, conservation area requirements, or complex groundworks can push costs beyond £175,000.)
Why Catford Clients Choose Buildaway
- Lewisham planning knowledge — practical familiarity with Lewisham Council's planning policies, conservation area guidance, and the Victorian and Edwardian housing stock that defines Catford's residential character.
- Fully transparent pricing — detailed, itemised quotations broken down by trade and project stage, with no vague allowances or charges introduced once work is underway.
- 18-month labour warranty — delivering greater post-completion assurance to Catford homeowners than the standard defects liability period offered by most comparable local contractors.
- Fully accredited and insured — Gas Safe registered, NICEIC certified, and carrying comprehensive public liability insurance on every project without exception.
- Complete project management — Buildaway coordinates architects, structural engineers, Party Wall surveyors, and all specialist trades from first consultation through to final Building Control sign-off.