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.
What pushes loft conversion prices up 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 runs about 35% above the UK average on loft conversion: budget £40,500 to £101,250 per conversion, supported by a large urban contractor pool. 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.
Expect £40,500 to £101,250 per conversion for loft conversion in London, over roughly 8-14 weeks, given the local rate runs about 35% above the UK average. 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 price tiers in London (£40,500 to £101,250)
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 runs 35% over the UK average for loft conversion
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.
How do I get a fair loft conversion price in London?
Get at least three written, itemised quotes so you can compare like for like, and tell each firm exactly the same brief. A basic loft conversion job in London starts around £40,500, while a complex one can reach £128,250 per conversion. Quotes near the bottom of that range usually mean a more basic spec, not a better deal, so check what's actually included before you choose on price alone.
See all loft conversion prices across the UK or browse all tradespeople costs in London.
More building & construction in London: Kitchen Installation costs, Single Storey Extension costs, Plastering (Per Room) costs, Wall & Floor Tiling costs.