House Extension, Home Renovation and Loft Conversion Builders in Dulwich, SE21 & SE22
Running out of space in your Dulwich home doesn’t mean leaving one of South London’s most desirable neighbourhoods. Whether your Victorian terrace kitchen feels impossibly narrow or your Edwardian semi needs an extra bedroom for a growing family, a well-designed extension or renovation lets you stay put and add real value to the property in the process. Design And Build works with homeowners across Dulwich Village, East Dulwich and West Dulwich, delivering extensions, loft conversions and full house refurbishments in SE21 and SE22 — with the design, planning, structural engineering and construction all managed under one team.
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Dulwich: A South London Village That Never Quite Left Its Georgian Roots
Straddling SE21 and SE22, Dulwich is one of the few parts of London that genuinely earns the word “village.” Dulwich Village itself centres on a cluster of independent shops, cafés, and the Dulwich Picture Gallery — England’s first purpose-built public art gallery, opened in 1817 — all set among tree-lined streets that feel a world away from the pace of central London despite being a short journey from it. East Dulwich adds a livelier edge around Lordship Lane’s restaurants and boutiques, while West Dulwich offers a quieter, more residential alternative. Across all three, families are drawn in by strong schools, sizeable gardens, and green space including Dulwich Park and the ancient woodland at Sydenham Hill.
A Rare Concentration of Period Housing
Few areas of London can match Dulwich’s stock of Georgian and Victorian property. Around Dulwich Village, grand double-fronted homes — some listed, some dating to the 1700s — sit alongside substantial Victorian and Edwardian villas, many governed by the Dulwich Estate’s Scheme of Management, which sets its own rules on how properties can be altered. Head into East Dulwich and the housing shifts toward Victorian terraces and semis around Lordship Lane and Calton Avenue — generously proportioned but more typical of everyday family life than showpiece architecture. West Dulwich, meanwhile, out towards West Norwood, leans toward large detached houses, many built in the 1920s. Flats exist but remain a smaller part of the market here — this is overwhelmingly a house-owning neighbourhood, and one where staying and extending is usually a more realistic option than trading up.
Two Consents, Not One: Why Building in Dulwich Is Different
This is the thing that catches people out in Dulwich, and it is worth understanding before you commission any drawings.
A large proportion of Dulwich property sits within the Dulwich Estate’s Scheme of Management — created in January 1974 under section 19 of the Leasehold Reform Act 1967, and covering around 1,500 acres managed by the trustees of a charitable foundation that has held the land for four centuries. If your property is within it, you need written consent from the Estate, granted in the form of a licence, before carrying out external alterations.
That consent is separate from, and in addition to, local authority planning permission — and the two are independent of each other. The Estate is explicit that if one organisation grants consent, it does not follow that the other will. A scheme approved by the council can still be refused by the Estate, and the reverse is equally possible. Note too that the Estate’s land spans three boroughs, so depending on your address the council side may be Southwark, Lambeth or Lewisham.
The Estate’s Guidelines for Residents set the design criteria for extensions, loft conversions, replacement windows, hard standings, garden structures, swimming pools, satellite dishes and works to trees. They have been updated to cover newer questions too — solar panels, ground source heat pump and other mechanical plant installations, and electric vehicle charging points. We read the current Guidelines against your specific proposal rather than working from what was permitted on a neighbour’s house some years ago.
Alongside all of that sit Southwark’s own Dulwich Supplementary Planning Document, which sets expectations on scale, materials and design particularly around Dulwich Village, East Dulwich and Herne Hill, and standard conservation area protections. National permitted development rights still apply in principle but are significantly narrowed here by conservation area status, Estate covenants and, in places, designated land status. Where permitted development doesn’t cover the work, full planning permission is required — and applications using non-traditional materials, mismatched window proportions, or which don’t properly account for neighbouring amenity are a common cause of refusal.
Signature Dulwich Extension and Renovation Projects
The area’s Victorian and Edwardian housing stock — with its wide bay windows, timber sash windows, and deep front gardens — suits a fairly consistent set of projects:
Single-storey rear extensions are the most common project in Dulwich, typically opening up a cramped rear kitchen into a bright, garden-facing kitchen-diner.
Side-return extensions work particularly well on the L-shaped Victorian terraces common around East Dulwich and Lordship Lane, filling the narrow side strip to widen the ground floor and bring in light through rooflights or a glazed roof.
Wraparound extensions combine both, and suit homeowners after maximum ground-floor space for an open-plan kitchen, dining and living layout.
Double-storey rear extensions add bedroom and bathroom space above as well as living space below, and tend to deliver the strongest value per square metre for larger family homes.
Loft conversions are especially effective on Edwardian houses with steeper roof pitches — L-shaped dormers suit the Victorian villas, while hip-to-gable conversions are usually the better fit for Edwardian semis, often adding a principal bedroom with en-suite. The same roof types run east into Forest Hill and Sydenham.
Full house renovations are just as common as extension work here, particularly on properties that haven’t been updated in decades — rewiring, replumbing, reconfigured layouts, and modernised kitchens and bathrooms with our interior design team, often carried out alongside an extension so the finished property is brought up to one consistent standard throughout.
Building Sustainably in Dulwich
Energy performance is an increasingly important part of any Dulwich project, and the Estate has been updating its Guidelines to address it — the current version covers solar installations, ground source heat pumps and other mechanical plant, and electric vehicle charging points, none of which the older guidance dealt with directly. On our projects that typically means high-performance insulation across walls, roofs and floors, double or triple glazing detailed to match heritage window styles where conservation rules apply, careful airtightness detailing that doesn’t compromise ventilation, and — where it makes sense for the property — solar PV, air-source heat pumps, or underfloor heating designed in from the start rather than retrofitted later. Better performance isn’t just an environmental consideration in Dulwich’s market — it has a direct bearing on EPC rating and, increasingly, on resale value.
Navigating Planning and Estate Consent
Because Dulwich sits at the intersection of council planning policy and the Dulwich Estate’s separate consent process, getting a scheme through cleanly means addressing both from day one rather than treating the Estate as an afterthought once council planning is sorted. Our process starts with a proper site survey and a check of the property’s conservation area status and Estate obligations, followed by a design concept developed to satisfy both together. Where useful we raise pre-application queries with the council and the Estate in parallel — the Estate itself suggests submitting to both simultaneously to save time — since this front-loaded approach avoids the redesigns that come from a scheme satisfying one authority but not the other.
What a Dulwich Extension Typically Costs
As a general guide: a single-storey rear extension of around 25 square metres typically runs £55,000–£70,000 build-only, or £70,000–£90,000 fully finished including kitchen fit-out. Wraparound extensions sit in a broadly similar cost-per-square-metre range, though bespoke glazing and structural steelwork push costs higher. Double-storey rear extensions typically run £2,000–£2,600 per square metre build-only, rising to £2,600–£3,300 fully finished — a 40 square metre project often lands around £105,000–£130,000 turnkey. Loft conversions in Dulwich generally start from around £50,000 depending on scope and roof type. Treat these as orientation rather than a price. After a site visit you get a line-by-line quote built around your own house, not a borough average.
How We Deliver a Project in Dulwich
Conceptual design and consultation. We start with a free home visit, survey the property, and discuss your budget and the specific challenges it presents — uneven Victorian foundations, restrictive side access, conservation area or Estate constraints. You’ll typically have a conceptual design and an initial cost estimate within a couple of weeks.
Structural engineering and planning. Once you’re happy with the concept, we produce detailed architectural drawings, structural calculations, and the full set of planning, building control, and — where relevant — Dulwich Estate consent submissions, run in parallel rather than sequentially so approvals don’t cascade into delay. Where a shared wall is affected, the Party Wall etc. Act 1996 applies and our party wall surveyors serve the notices alongside.
Construction. With permissions secured, our team manages the build from groundworks and steelwork through plumbing, electrics, plastering and decoration, with a single point of contact throughout and regular progress updates.
Handover. Every project finishes with a proper inspection and snagging process, building control sign-off, and a workmanship guarantee, with aftercare support beyond completion day.
Working With Dulwich’s Period Properties
Period homes in Dulwich often present a few predictable surprises once work starts — uneven original foundations, structural movement, damp, or decayed timber that wasn’t visible at survey stage. Where steel beams are needed to open up a span, or underpinning is required for a deeper foundation, that structural engineering is handled in-house rather than outsourced. Matching original brickwork, reproducing period pointing, sourcing appropriate reclaimed materials, and specifying sash windows that satisfy Estate guidelines are treated as standard specification on Dulwich projects, not an optional upgrade — because on a property this age, in an area this closely regulated, the detailing is very often what decides whether a scheme is approved and how well it ages once built.
Start Your Dulwich Project
Dulwich’s Georgian and Victorian housing has real, well-proven potential for extension and renovation — the challenge is navigating council planning policy and the Dulwich Estate’s separate consent process together, rather than discovering the gap between them partway through a project. Whether you’re considering a side-return extension, a loft conversion, or a full house renovation, we’re happy to visit your property, assess what’s realistically achievable, and talk through scope, cost and timeline. We also work across neighbouring Peckham, Gipsy Hill and the rest of south east London.
Arrange your free, no-obligation consultation with Design And Build today.
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