Tenfold Renovation designs and builds loft conversions across South London – rear dormers, hip-to-gable, L-shaped dormers, mansards and rooflight conversions – turning unused roof space into bedrooms, en-suite bathrooms and home offices without losing any garden. One team handles the design, the planning or permitted development route with your council, building regulations, party wall notices and the build itself, so you deal with one company from first survey to final sign-off.
Call 020 8064 0975 or book a free survey and we will check your loft, measure up and talk through what is possible for your home.
We work from our base in SW19 and convert lofts across South and South-West London, including:
- Wimbledon, Raynes Park and Colliers Wood (Merton) – see loft conversions in Wimbledon and Merton
- Clapham, Brixton and Streatham (Lambeth) – see loft conversions in Clapham
- Battersea, Balham, Tooting and Wandsworth (Wandsworth) – see loft conversions in Battersea
- Sutton, Cheam and Carshalton (Sutton) – see loft conversions in Sutton
- Croydon, Purley and Thornton Heath (Croydon) – see loft conversions in Croydon
See our local loft conversion pages for Wimbledon, Clapham, Battersea, Sutton and Croydon. Need space downstairs too? See our house extensions in South London. Choosing a builder? Read how to choose a loft conversion company in London.
Rear Dormer Loft Conversion
The most common loft conversion on London terraces. A box-shaped dormer on the rear roof slope adds full head height and floor space for a bedroom and bathroom, and many fall under permitted development within the volume limits.
Hip-to-Gable Conversion
For semi-detached and end-of-terrace houses with a sloping (hipped) side roof. The side slope is rebuilt as a vertical gable wall, creating room for a staircase and a larger loft – often combined with a rear dormer.
L-Shaped Dormer
Two dormers joined over the main roof and the back addition of a Victorian or Edwardian terrace. It creates the most space on this type of house – often two bedrooms and a bathroom.
Mansard Loft Conversion
The back roof is rebuilt at a steep angle with a flat top, giving the most usable space of any loft. It almost always needs planning permission, but suits many period streets where neighbours already have mansards.
Rooflight Conversion
If your loft already has good head height, adding roof windows (Velux-style) is the quickest and least disruptive option. The roof shape stays the same, so planning permission is rarely needed.
Not Sure Which Suits Your Home?
Book a free survey. We check your loft's head height, roof structure and where the new stairs could go, then tell you which options are realistic before you pay for drawings.
Not always. Many rear dormer, hip-to-gable and rooflight conversions can be built under permitted development, but mansards, front dormers and any loft that goes beyond the limits need planning permission. Lofts in conservation areas are not permitted development, and many South London neighbourhoods are conservation areas or have Article 4 directions – for example parts of Wimbledon, Clapham, Battersea and Cheam – so roof changes there need planning permission. Building regulations approval is needed in every case.
Under permitted development (England, houses only – not flats or maisonettes), a loft conversion must generally have:
- no more than 40 m³ of extra roof space on a terraced house, or 50 m³ on a semi-detached or detached house;
- nothing built forward of the existing roof slope on the front of the house facing a road;
- no higher than the highest part of the existing roof;
- no verandas, balconies or raised platforms (a Juliet balcony is normally fine);
- materials similar in appearance to the house, with side-facing windows obscure-glazed and fixed below 1.7 m;
- roof enlargements set back at least 20 cm from the original eaves, where practical.
We check your property’s planning history and whether it sits in a conservation area before design starts, and we recommend a Lawful Development Certificate for permitted development lofts so you have proof when you sell. Sources: Planning Portal – Loft conversion.
Most loft conversions on terraced and semi-detached houses involve cutting steel beams into the shared party wall, so the Party Wall etc. Act 1996 usually applies. We tell you early which neighbours need a notice and when, so the build is not delayed. If a neighbour consents in writing, work can go ahead; if not, a party wall surveyor agrees how the work will be carried out.
1. Free Survey and Loft Check
We visit your South London home, check head height, roof structure and stair position, and talk through your budget.
2. Design and Drawings
Floor plans, elevations and layout options for bedrooms, bathroom and storage.
3. Planning or LDC
We submit the planning application or Lawful Development Certificate to your local council.
4. Building Regulations
Structural calculations, fire-safe escape route, insulation and stairs – building control approval arranged by us.
5. Build
Scaffold, steelwork, dormer and roof, insulation, new staircase, electrics, plumbing and finishing.
6. Sign-Off and Handover
Building control completion certificate and a final walk-round with you.
The price depends on the type of conversion, the size of your loft, the roof structure, the number of rooms and bathrooms, and finishes. On terraced streets, scaffold and skip licences and parking also need planning in advance, and homes in conservation areas may need specific roof materials. A rooflight conversion is usually the most affordable; rear dormer and hip-to-gable conversions sit in the middle; a mansard costs the most because more of the roof is rebuilt. For typical London price ranges, see our guide How Much Does a Loft Conversion Cost in London?.
After the survey we give you a fixed, itemised written quote, so you know exactly what is included before any work starts.
Rated 5.0 from 14 Google reviews.
Yvonne – Large and Small Projects
“Vitaliy and his team go above and beyond, are efficient, punctual, work full days and clearly care for their customers. I have used Tenfold Renovation for large and small projects …”
★★★★★ Google review
Linda – Large Renovation
“Quite a large job done at my property. Excellent workmen, respectful of my property … workmanship was first class. Would highly recommend them.”
★★★★★ Google review
Jolene – Home Renovation
“I have been very impressed by the works carried out by Vitaliy and his team all completed to an excellent standard. They were reliable, hard working clean and tidy …”
★★★★★ Google review
How long does a loft conversion in South London take?
Most loft conversions take around 6–10 weeks on site, depending on the type – a rooflight conversion is quicker, a mansard or L-shaped dormer takes longer. Design and approvals add time before work starts, so we give you a full timeline after the survey.
Is my loft suitable for a conversion?
Most pitched roofs in South London can be converted. The key checks are head height, the roof structure (modern trussed roofs need more structural work than traditional rafters) and where the new staircase can go. We check all three at the free survey.
Which loft conversion adds the most space?
A mansard usually gives the most usable space, followed by an L-shaped dormer on a terrace with a back addition. A rear dormer is the most common balance of space and cost, and a hip-to-gable is usually the best option for semi-detached houses with a sloping side roof.
Can I stay at home during a loft conversion?
Usually yes. Most of the work is done from scaffolding outside, and the loft is only opened up to the rest of the house near the end, when the new staircase goes in.
Which areas do you cover?
We convert lofts across Merton, Lambeth, Wandsworth, Sutton and Croydon – including Wimbledon, Clapham, Battersea, Balham, Tooting, Streatham, Sutton, Cheam and Croydon – working from our base in SW19.
Would an extension be better than a loft conversion?
It depends on what you need: a loft adds bedrooms and a bathroom without using garden space, while an extension adds ground-floor living space. Compare both in our guide Loft Conversion vs House Extension, or see our house extensions in South London.
Contact Us Now
Reach out today to discuss your extension project with our friendly and experienced team.
We Are Experienced
Tenfold Renovation has been designing and building loft conversions, extensions and renovations across South and South-West London for many years, working from our base in SW19.
Loft Conversion Specialists in South London
We work with experienced architects and structural engineers, and our own team covers every trade a loft needs – scaffolding, steelwork, carpentry, roofing, insulation, electrics, plumbing and decorating – all managed by one project lead, so nothing falls between contractors.
Top Quality of Work
Our clients regularly mention tidy work, respect for their home and work finished to a high standard. You can read their Google reviews above.
Safety Is Our Top Concern
Working at height needs proper scaffolding, edge protection and safe access, so our team follows strict safety procedures throughout, keeping the site safe for our workers and for everyone living in the house.
Tell us about your home and how you would like to use the loft. We will check your roof space, measure up and give you a fixed, itemised written quote – call 020 8064 0975, email office@tenfoldrenovation.com or send us your details.