Building & Construction · Greater London

Cost of Loft Conversion in Lewisham (2026)

If you're looking at loft conversion in Lewisham right now, you should be seeing quotes in the £36,000 to £90,000 range per conversion. That's based on current Greater London contractor rates and the wider UK market. Anything well outside those numbers is worth questioning before you sign.

Typical cost in Lewisham +20%
Low £36,000
Typical £63,000
High £90,000
Typical price per conversion Last updated 22 April 2026
  • FMB Federation of Master Builders
  • TrustMark Government-endorsed
  • FENSA Glazing installer scheme
  • NHBC Warranty-backed builds

About loft conversion in Lewisham

Lewisham is a large city of around 306,000 in Greater London. The housing is mostly South East London properties span Victorian terraces, post-war council estates and new-build apartment blocks. That matters: older properties usually mean more pipework, rewiring and retrofit surprises, while newer builds in districts like SE4, SE6, SE8 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 Lewisham

Basic £36,000 – £50,400

Simple Velux conversion with no structural changes

Standard £50,400 – £69,600

Dormer conversion with new stairs and ensuite

Complex £69,600 – £114,000

Hip-to-gable or mansard conversion, two rooms plus ensuite

What affects the price of loft conversion in Lewisham?

  • Type (Velux, dormer, hip-to-gable, mansard)
  • Structural steel requirements
  • Ensuite addition
  • Party wall agreements
  • Planning permission (where PD is insufficient)

Lewisham vs the UK average

Lewisham sits in the building & construction market at a cost multiplier of 1.20× the UK national average. That puts Lewisham loft conversion prices at £36,000–£90,000 versus the UK average of £30,000–£75,000 per conversion.

Lewisham vs UK national average — per conversion Lewisham £36,000 £90,000 UK average £30,000 £75,000
Typical price range, per conversion

Loft Conversion cost calculator — Lewisham

Estimated cost in Lewisham
£52,920 – £73,080
per conversion

Estimate based on live 2025 UK trade pricing. Always get 3 written quotes before committing.

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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 Lewisham?

Budget £36,000 to £90,000 per conversion for loft conversion in Lewisham. Prices here are around 20% 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 Lewisham?

A straightforward loft conversion job in Lewisham 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 Lewisham?

A proper loft conversion quote in Lewisham 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 Lewisham than the UK average?

Loft Conversion in Lewisham runs around 20% more expensive than the UK average. The UK-wide benchmark for this job is £30,000 to £75,000 per conversion; Lewisham quotes tend to land between £36,000 and £90,000. Handy to know what the average actually looks like before you price round.

Do I need planning permission for loft conversion in Lewisham?

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.