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Extensions, loft conversions and full refurbishments across South East London — from Victorian terraces in Dulwich and Forest Hill to suburban semis in Beckenham, Bromley and Croydon. Fixed-price, director-led building with building-regs sign-off as standard.
South East London ranges from grand Victorian and Edwardian villas around Dulwich Village and Forest Hill to tight terraced streets in Lewisham and Catford and 1930s suburban semis spreading out through Beckenham, Bromley and Croydon. The period stock is ideal for loft conversions and rear extensions, while the inter-war semis suit side and rear extensions and garage conversions.
Rear and side-return extensions are the most common brief across the South East London terraces, opening up narrow kitchens into open-plan family space. In Dulwich and Forest Hill we more often take on full-house refurbishments and loft conversions on period properties, while in Beckenham, Bromley and Croydon the typical projects are double-storey extensions, garage conversions and full reroofs on ageing semis.
South East London has become one of the strongest renovation markets in the capital as families priced out of areas further west move in for the space, the schools and the green belt around Dulwich and Beckenham. The common thread is the same: a growing family that loves the area and wants to extend rather than move.
South East London is really two markets stitched together. Closer in — Dulwich, Forest Hill, Brockley, Honor Oak — you have grand Victorian and Edwardian villas and tight period terraces, much of it untouched for decades and ideal for loft conversions and side-return extensions. Further out, through Beckenham, Bromley and Croydon, the stock shifts to generous 1930s semis and detached homes on wide plots that lend themselves to rear and double-storey extensions and garage conversions.
One thing nearly every property here shares is what's underneath it: London Clay. It's a shrink-swell soil that moves with the seasons and with nearby trees, which is why extension foundations in this part of London often need to go deeper than homeowners expect — and why a proper site assessment before quoting matters. We design foundations around the actual ground conditions and tree proximity, not a guess.
South East London has an unusually high concentration of conservation areas — Dulwich Village, Forest Hill, Sydenham, parts of Beckenham and South Croydon among them — where permitted-development rights are restricted and external changes that would be automatic elsewhere need a full planning application.
Dulwich carries an extra layer most homeowners don't know about until late: much of the former Dulwich College Estate is governed by the Dulwich Estate Scheme of Management, which requires the Estate's own consent for external alterations — separately from, and on top of, planning permission from Southwark. Miss it and the work isn't lawful. We build both approvals into the programme from the start so neither holds up your job.
Conservation areas plus the Dulwich Estate Scheme of Management — external alterations typically need the Estate's consent in addition to planning permission. Budget time for both approvals.
Multiple conservation areas where front and roof alterations frequently need permission even where permitted development might otherwise apply.
Leafy suburbs with conservation areas including the private Cator Estate; generous plots suit rear and double-storey extensions and garage conversions.
Suburban conservation areas and Article 4 directions (notably around HMO conversions) apply in several wards — confirm your street's status before assuming permitted development.
Denser Victorian terraces; rear dormers and side-returns are usually permitted development outside the conservation areas.
| Project | Typical cost | Notes |
|---|---|---|
| Loft conversion (dormer) | £45k–£70k | Common on the area's Victorian and Edwardian terraces |
| Single-storey rear extension | £45k–£75k | 15–25m² open-plan kitchen-diner |
| Side-return extension | £55k–£90k | Terraces in Dulwich, Forest Hill and Brockley |
| Double-storey extension | £80k–£130k | Suits the larger Bromley and Croydon semis |
| Full refurbishment | from £1,200/m² | Period homes around Dulwich Village |
Honest London ranges for a completed, mid-specification project — a starting point for budgeting, not a fixed quote. For the full breakdowns see our loft conversion and house extension cost guides.
Single and double-storey rear extensions, side-returns and wrap-arounds.
Mansard, dormer, hip-to-gable and L-shape loft conversions with full sign-off.
Repairs, reroofs, slate, tile, flat roof and leadwork.
Structural openings, repointing, garden walls and period restoration.
Paving, driveways, retaining walls, planters, pergolas and lighting.
Quite possibly two consents. Many properties on the former Dulwich College Estate are covered by the Dulwich Estate Scheme of Management, which requires the Estate's approval for external alterations — separately from, and in addition to, planning permission from Southwark. We factor both into the programme so neither holds up your start date.
It might well be — Dulwich Village, Forest Hill, Sydenham, and parts of Beckenham and South Croydon all sit within conservation areas where permitted-development rights are restricted and external changes need permission. We check your exact address against the council's conservation-area maps before designing, so there are no surprises.
Yes — we work right across South East London, including Dulwich, Forest Hill, Lewisham, Beckenham, Bromley and Croydon. Your initial site survey and fixed-price quote are free with no obligation.
A side-return or rear extension is the most requested project — knocking the galley kitchen through into the side return to create a wide, open-plan kitchen-diner with roof lights and doors to the garden. Most are permitted development, so no full planning application is needed.
Yes. We prepare and submit planning applications or permitted development certificates where needed, and building regulations sign-off is included as standard on every project.
Every project carries our 1-year workmanship guarantee and £2M public liability insurance. Certificates are available on request.
Send us the address and a rough brief — a director will reply within one working day with a free, no-obligation quote.