Ramsden Road, Balham SW12
L-shaped dormer over the rear outrigger adding a master bedroom and en-suite to a Victorian mid-terrace.
- L-Shaped Dormer
- 11 weeks
- £72k
- Wandsworth Council
- Delivered by us
Loft Conversions in Balham SW12
The London Loft Conversion Company designs and builds loft conversions across Balham and the surrounding SW12, SW17 and SW11 postcodes, around 20 minutes from our Fulham base. One in-house team for feasibility, design, planning, structural engineering and the build itself. One fixed price, VAT included, written contract.
- Typical project
- £56k–£70k, 8–12 weeks
- Area
- Balham SW12 (SW17, SW11)
- Local council
- Wandsworth / Lambeth
- Best for
- Victorian and Edwardian terraces
Why Balham is one of the best parts of London for a loft conversion
Balham grew fast once the railway arrived, and the result is street after street of Victorian and Edwardian terraces built between the 1880s and the early 1900s, running from Clapham Common's south side down to Tooting Bec Common. Almost all of them have a rear back addition ("outrigger"), which is exactly the footprint an L-shaped dormer builds over. It is the classic Balham conversion: a master bedroom and a proper bathroom in one project, with nothing visible from the street.
Planning sits with Wandsworth Council across most of SW12, with Lambeth Council picking up the eastern edges around Cavendish Road and Hydethorpe Road. Full applications typically take 8–10 weeks; Lawful Development Certificates, which cover most Balham dormers, are usually decided in around 6 weeks. The Heaver Estate conservation area off Bedford Hill, with its grand red-brick terraces, controls roof alterations closely, and a well-designed mansard in keeping with the estate roofline is often the accepted route there. The Hyde Farm Estate conservation area toward Tooting Bec Common has its own restrictions on the Edwardian cottage terraces.
We're around 20 minutes by road from our Fulham base, which means same-day or next-working-day survey visits across Balham. A good share of our SW12 work comes through neighbour referrals. Terraced streets talk, and once one loft is done well, the scaffolding tends to move a few doors down.
Recent loft conversions in Balham
A selection of dormer, L-shaped and mansard projects we've delivered in SW12 and the immediately surrounding postcodes, labelled clearly so you can see whether the build was through The London Loft Conversion Company or our parent company, Pillarstone Operations Group.
Ritherdon Road, Balham SW17
Rear mansard on a red-brick Heaver Estate terrace, designed in keeping with the estate roofline and approved with a full heritage statement.
- Mansard
- 14 weeks
- £92k
- Wandsworth Council
- Delivered by us
Endlesham Road, Balham SW12
Rear dormer with double bedroom and walk-in shower on an Edwardian terrace, a short walk from Balham station.
- Dormer
- 9 weeks
- £60k
- Wandsworth Council
- Group-delivered
Alderbrook Road, Balham SW12
Full-width rear mansard creating a principal bedroom suite with dressing area on a Victorian terrace between the commons.
- Mansard
- 15 weeks
- £98k
- Wandsworth Council
- Group-delivered
Hydethorpe Road, Balham SW12
Rear dormer creating two children's bedrooms with a reconfigured landing on the Lambeth side of Balham.
- Dormer
- 10 weeks
- £63k
- Lambeth Council
- Group-delivered
Fernlea Road, Balham SW12
L-shaped rear dormer with a bespoke oak staircase and a glazed gable end pulling light down to the floor below.
- L-Shaped Dormer
- 12 weeks
- £76k
- Wandsworth Council
- Group-delivered
Our projects in and around Balham
Which loft conversion suits a Balham home?
Most Balham properties fall into two or three roof types, and the right loft conversion depends on yours. Here's the short version.
L-Shaped DormerWhy it suits Balham
The Balham classic. Nearly every Victorian and Edwardian terrace between Clapham Common and Tooting Bec Common has a rear outrigger, and an L-shaped dormer builds over it to add two rooms, usually a master bedroom and a generous bathroom. Permitted development on the vast majority of houses outside the conservation areas.
£66,000 – £82,000
Read more about l-shaped dormersRear DormerWhy it suits Balham
The most cost-effective option for the straight-roofed terraces off Balham High Road and toward Wandsworth Common. Usually permitted development, with a finished cost typically £56k–£70k for a master bedroom and en-suite.
£56,000 – £70,000
Read more about rear dormersMansardWhy it suits Balham
The right call for the Heaver Estate's grand red-brick terraces off Bedford Hill, where roof alterations are closely controlled and a mansard in keeping with the estate roofline is often the accepted route. Rebuilds the rear roof at a steep angle to create a full new storey with vertical walls inside.
£76,000 – £102,000
Read more about mansardsPlanning permission in Balham: what you actually need to know
When you'll usually need planning permission in Balham
- Mansards, which always need a full application
- Front-facing dormers, almost always
- Any conversion of a flat or maisonette
- Properties within the Heaver Estate or Hyde Farm Estate conservation areas
- Listed buildings (rare in SW12 but worth checking)
- Properties where previous extensions have used up the permitted development "allowance"
- Anything that significantly alters the ridge line or chimney stacks
Conservation areas affecting Balham
- Heaver Estate Conservation Area — The grand red-brick terraces off Bedford Hill between Balham and Tooting Bec. Roof alterations are closely controlled; mansards designed in keeping with the estate roofline are often the accepted route.
- Hyde Farm Estate Conservation Area — Edwardian cottage terraces toward Tooting Bec Common on the eastern edge of SW12. Rear dormers typically restricted; Velux or sensitively designed rear alterations are usually recommended.
- Conservation pockets toward Nightingale Lane — Some streets between Balham and Wandsworth Common have local conservation considerations. We check your exact street before quoting.
Local councils
Lambeth Council
Covers the eastern edges of SW12 around Cavendish Road and Hydethorpe Road
Planning portal: lambeth.gov.uk/planning
Typical planning timeline
- Full application (with either council)
- 8–10 weeks
- Lawful Development Certificates
- ~6 weeks
We handle every part of this: Lawful Development Certificates, full planning applications, Design & Access Statements, conservation-area heritage statements, council liaison and responding to planning officer queries, all as part of your fixed quote. You don't deal with the council, we do.
What does a loft conversion in Balham cost?
Balham pricing sits close to Clapham because the housing stock is so similar: solid Victorian and Edwardian terraces, conservation oversight on the Heaver and Hyde Farm estates, and high finish expectations from SW12 homeowners. The ranges below are 2026 figures for terraces in SW12 and the SW17 and SW11 edges. Final quotes are confirmed in writing after a free home survey.
| Type | Typical range | Build time | Planning |
|---|---|---|---|
| Velux | £40,000 – £50,000 | 6–8 weeks | Usually permitted development |
| Dormer | £56,000 – £70,000 | 8–10 weeks | Usually permitted development |
| L-Shaped Dormer | £66,000 – £82,000 | 10–12 weeks | Often permitted development |
| Hip-to-Gable | Less common in SW12 | – | – |
| Mansard | £76,000 – £102,000 | 12–16 weeks | Planning permission required |
VAT included. Final price varies with structural complexity, spec and finish. Your proposal is itemised line by line before any commitment.
Book a free survey for your Balham quoteWhat our Balham clients say
We were nervous about committing to such a big project, but the team made it the smoothest experience. They stayed on budget, finished a week early and even sorted the snags before we'd noticed them. Our bedroom is the best room in the house now.
Sarah & Tom
L-shaped dormer · Clapham
From the first survey to handover, everything happened when they said it would. The fixed price genuinely was fixed, and the weekly photo updates meant we always knew exactly where the build was. The dormer has completely changed how we use the house.
James R.
Rear dormer · Wandsworth
Our loft was a dumping ground for ten years and now it's the nicest room we own. The crew were tidy, polite and honest about what was possible, and the finish is better than we dared hope for.
Rebecca H.
Mansard · Fulham
Loft conversion questions from Balham homeowners
How much does a loft conversion in Balham cost?
Loft conversions in Balham typically cost £56,000 to £102,000 depending on the type and the property. A standard rear dormer on a Victorian terrace usually falls between £56,000 and £70,000. L-shaped dormers, the most common choice on Balham's outrigger terraces, run £66,000 to £82,000. Mansards, often the route on the Heaver Estate, are £76,000 to £102,000, and a Velux conversion starts from around £40,000. Every figure is VAT included and confirmed in writing after a free home survey.
Do I need planning permission for a loft conversion in Balham?
Often not. Rear dormers and L-shaped dormers on Balham houses usually fall under permitted development, needing only a Lawful Development Certificate. You will need planning permission for a mansard, for any conversion of a flat or maisonette, and for most work within the Heaver Estate or Hyde Farm Estate conservation areas. We assess your street's exact position at the free survey and handle whichever route applies.
How long does Wandsworth Council take to approve a loft conversion in Balham?
A full planning application typically takes 8 to 10 weeks with Wandsworth, and the same with Lambeth on the eastern edges of SW12. A Lawful Development Certificate, which is all most Balham dormer conversions need, is usually decided in around 6 weeks. We prepare and submit everything, deal with any planning officer queries, and build the approval time into your project programme.
What's the most common loft conversion type in Balham?
The L-shaped dormer. Almost every Victorian and Edwardian terrace between Clapham Common and Tooting Bec Common has a rear outrigger, which is exactly the footprint an L-shaped dormer builds over, adding a master bedroom and a generous bathroom in one project. Straight rear dormers are the next most common, particularly on the streets off Balham High Road.
Can I convert a loft on the Heaver Estate?
Usually, yes, but the type matters. The Heaver Estate conservation area off Bedford Hill controls roof alterations closely, so a standard rear dormer is often refused. A mansard designed in keeping with the estate's red-brick roofline is typically the accepted route, supported by a heritage statement and full planning application, which we prepare as part of the fixed quote.
Which council covers my Balham house, Wandsworth or Lambeth?
Most of Balham falls under Wandsworth Council, including the streets between the commons and the SW17 edge toward Tooting Bec. Lambeth picks up the eastern edges of SW12 around Cavendish Road and Hydethorpe Road. We confirm which council your house falls under at the survey and submit to the right one. The process and your fixed price are the same either way.
We also work in nearby areas
Don't see Balham as your nearest postcode? We work across London. Most of our work comes from referrals between neighbouring streets.
- Loft Conversions in Clapham
- Loft Conversions in Tooting
- Loft Conversions in Streatham
- Loft Conversions in Wandsworth
- Loft Conversions in Battersea
- Loft Conversions in Wimbledon
Looking for a specific postcode? See all the South London areas we cover or West London areas.
Ready to start your Balham loft conversion?
Tell us your postcode and a bit about your house. Daniel will arrange a free home survey, usually within 5 working days in SW12, and you'll have a fully itemised fixed-price proposal within 7 days of the visit. No pressure, no obligation, no hard sell.
- Free home survey, usually within 5 working days in Balham
- Itemised fixed-price proposal within 7 days of the survey
- 15% deposit only after you sign · 5% retention held until snagging is signed off
- VAT included in every figure
Prefer to talk? Call Daniel on 07414 648 263.