Wimbledon (SW19) is one of South West London’s most desirable residential areas, famous worldwide for the All England Lawn Tennis Club and Wimbledon Tennis Championships, as well as its village feel, green spaces like Wimbledon Common, and excellent transport links to central London. With a mix of period terraces, Edwardian semis, and larger detached homes, space is always in demand — and loft conversions have become one of the most popular ways to add bedrooms, en-suites, or home offices without moving.
This Wimbledon-specific guide gives you accurate 2025 price ranges, explains what’s included, what can push costs up or down, the planning and regulations to be aware of in Merton, realistic timelines, ROI potential, and expert tips on choosing the right builder.
How much does a loft conversion cost in Wimbledon?
Pricing below reflects South West London / Merton market rates for 2025 (labour + materials), with compliant insulation, structural work, and a professional finish.
| Conversion Type | Typical Total Range (2025) | Best For | What You Typically Get |
|---|---|---|---|
| Velux / Rooflight | £25,000 – £35,000+ | Fastest / most economical | Structural steels/floor, insulation, 1–2 rooflights, plaster/paint, sockets, heating tie-in |
| Rear Dormer (most popular) | £35,000 – £55,000+ | Full-height bedroom + en-suite | Velux spec plus dormer structure, cladding/roofing, staircase, increased floor space & daylight |
| Hip-to-Gable (with or without dormer) | £50,000 – £65,000+ | 1930s semis / end-terraces | Hip extended to gable, additional steels, larger usable space, often with rear dormer |
| Mansard | £60,000 – £80,000+ | Victorian/period terraces | Roof rebuild, mansard walls/windows, bespoke staircase, high insulation, maximum space |
Add-ons to budget for:
- En-suite fit-out: £4,000 – £8,000+
- Juliet balcony / high-spec glazing: £2,000 – £6,000+
- Bespoke staircase & joinery: £1,500 – £4,000+
What’s included in those prices (and what isn’t)
Included:
- Measured survey, structural calcs, Building Control liaison
- New joists/steels, floor strengthening
- Roof alterations (Velux, dormer, hip-to-gable, or mansard)
- Thermal & acoustic insulation (Part L)
- Fire safety upgrades (Part B): smoke alarms, FD30 doors, escape windows
- Electrics & heating tie-in
- Plasterboard/skim, skirting & architraves
- Standard timber staircase to Part K
- Building Control inspections & completion certificate
Exclusions:
- Bathroom sanitaryware & tiling
- Designer finishes (crittall glazing, bespoke wardrobes, premium radiators)
- Planning application fees & Party Wall surveyors
- Full re-roofing beyond loft scope
- Decorating beyond mist coat/basic paint
What drives loft conversion cost up — or down
Factors increasing costs in Wimbledon:
- Conservation area restrictions (e.g., Wimbledon Village, South Park Gardens)
- Mansard roofs on Victorian terraces
- Complex steelwork in older properties
- Premium en-suite finishes with marble or stone tiling
- Juliet balconies with views over Wimbledon Common or Cannizaro Park
- Limited access/parking in narrow village streets
Ways to keep costs manageable:
- Stay within Permitted Development rights
- Align bathrooms above existing plumbing stacks
- Standard staircase design where possible
- Focus spend on visible finishes like lighting & brassware
Planning permission & building regulations in Wimbledon
Permitted Development (PD): Many Velux and rear dormers qualify, subject to volume and set-back rules.
Planning permission: Needed for mansards, front dormers, or properties in conservation areas (e.g., Wimbledon Village Conservation Area).
Party Wall Act 1996: Applies to most terraces and semis; allow £1,000–£2,000+ per neighbour for surveyor fees.
Building Regulations cover:
- Part A – structural work
- Part B – fire safety
- Part K – staircase compliance
- Part L – insulation/thermal performance
- Part P – electrics
- Ventilation – extractor fans for bathrooms
Timeline: how long does a loft conversion take?
- Pre-construction approvals: 3–8 weeks
- Velux conversion: 4–6 weeks
- Rear Dormer: 6–8 weeks
- Hip-to-Gable / Mansard: 8–12+ weeks
- Snagging & completion: 1–2 weeks
ROI: how much value can a loft conversion add in Wimbledon?
Adding a compliant double bedroom with en-suite in Wimbledon can increase property value by 10–20%, depending on the street and property type. Homes close to the District Line, Wimbledon Station, or Wimbledon Village shops see particularly strong returns.
How to choose the right loft conversion company in Wimbledon
- End-to-end design, structural, build, and finishing capability
- Transparent pricing with clear PC sums
- Proven compliance with Merton Council planning & Building Control
- Buildaway’s 18-month workmanship warranty
- Local experience across SW19, Wimbledon Park, and Southfields
Budget-smart tips (without cutting corners)
- Plan staircase location first to avoid wasted space
- Keep bathrooms/en-suites stacked above existing plumbing
- Prioritise insulation and airtightness for energy savings
- Upgrade “touch points” like lighting, flooring, and brassware for visible impact
Example Buildaway packages (guide pricing)
- Velux Room-in-Roof — £27,500–£34,500
Steels, rooflights, insulation, staircase, electrics, plaster finish. - Rear Dormer + En-suite Ready — £42,000–£56,000
Dormer, staircase, insulation upgrades, electrics/heating, plaster finish. En-suite +£4,000–£8,000. - Hip-to-Gable with Rear Dormer — £54,000–£68,000
Hip extension, dormer, steels, staircase, compliance, plaster finish.
(All prices include labour, materials, waste disposal, and Building Control. Final quotes vary by survey, access, and spec.)
FAQs (Wimbledon)
Do I need planning permission?
Not for most Velux/rear dormers under PD; yes for mansards, front dormers, or conservation areas.
Can I add an en-suite?
Yes, budget £4,000–£8,000+.
Will my roof need strengthening?
Almost always; new joists and steels are typical.
Can I live at home during the build?
Yes, with managed disruption.
What warranty do you provide?
18-month workmanship warranty.
Why Wimbledon homeowners choose Buildaway
Local expertise across SW19 and South West London
Proven compliance with Building Regulations & conservation rules
Transparent, itemised pricing
Skilled in-house trades from design through to completion
18-month workmanship warranty & responsive aftercare
High-quality materials and finishes for a lasting investment.