Cost of Loft Conversion in London (2026)
A typical loft conversion job in London costs £40,500 at the budget end and £101,250 for a full-spec install, per conversion. Outside peak season you'll usually get booked in within a week or two; summer runs tighter.
About loft conversion in London
London is a major city of around 8,982,000 in Greater London. The housing is mostly The EC area is dominated by converted warehouses, Georgian townhouses and new-build City fringe apartments. That matters: older properties usually mean more pipework, rewiring and retrofit surprises, while newer builds in districts like EC, WC, E tend to be quicker jobs with standardised fittings. Local trade prices sit on the expensive side for UK trade work. That's mostly wage levels plus the cost of running a van and a yard in and around Greater London.
London's the deepest trade market in the country, and also the priciest. ULEZ, congestion charge, parking permits, higher van insurance — it all feeds into the day rate. Most decent firms charge a callout and central boroughs run a clear premium over zones 4 and 5. Book two to three weeks ahead if you can.
Building jobs are labour-heavy, and materials have moved fast — brick, timber, steel, insulation and board are all 20 to 40 percent up on pre-2022. FMB and TrustMark are your best signposts for a proper builder. On anything bigger than a loft conversion, get a Building Control officer involved from day one; fixing non-compliance later costs a fortune.
Loft Conversion cost breakdown in London
Simple Velux conversion with no structural changes
Dormer conversion with new stairs and ensuite
Hip-to-gable or mansard conversion, two rooms plus ensuite
What affects the price of loft conversion in London?
- Type (Velux, dormer, hip-to-gable, mansard)
- Structural steel requirements
- Ensuite addition
- Party wall agreements
- Planning permission (where PD is insufficient)
London vs the UK average
London sits in the building & construction market at a cost multiplier of 1.35× the UK national average. That puts London loft conversion prices at £40,500–£101,250 versus the UK average of £30,000–£75,000 per conversion.
Loft Conversion cost calculator — London
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What's typically included in a loft conversion quote
- Structural calcs and Building Control
- Steels, joists and floor
- Stairs and Velux/dormer
- First and second fix
- Plastering and decoration
Frequently asked questions
How much does loft conversion cost in London?
Budget £40,500 to £101,250 per conversion for loft conversion in London. Prices here are around 35% more expensive than the UK average. What moves a quote inside that range is mostly building contractor day rates in Greater London and the specific material list for your job.
How long does loft conversion take in London?
A straightforward loft conversion job in London runs to 8–14 weeks. You can lose days to things outside the contractor's control — parts on backorder, awkward access, or a firm slotting your job around existing bookings. Ask for a start date and expected finish up front.
What's included in the price of loft conversion in London?
A proper loft conversion quote in London should cover: Structural calcs and Building Control; Steels, joists and floor; Stairs and Velux/dormer; First and second fix; Plastering and decoration. If any of those aren't itemised on your quote, push back and ask. A written guarantee with a clear warranty period is reasonable to expect on this kind of work.
Is loft conversion cheaper in London than the UK average?
Loft Conversion in London runs around 35% more expensive than the UK average. The UK-wide benchmark for this job is £30,000 to £75,000 per conversion; London quotes tend to land between £40,500 and £101,250. Handy to know what the average actually looks like before you price round.
Do I need planning permission for loft conversion in London?
Permitted Development covers many loft conversions in England (40m³ terraced, 50m³ semi/detached). Dormers to the front, conservation areas and listed buildings require planning consent. If the property sits in a conservation area or is listed, ring Greater London Council before you book anything in. It's a free call and saves a world of grief later.
See all loft conversion prices across the UK or browse all tradespeople costs in London.