Whole-house renovation (per m²) #

Headline per-square-metre bands for refurbishing an existing house, from cosmetic refresh to full gut-out.

Item2026 rangeUnitTypeBasisSource
# Light refurbishment £650–£900 per m² All-in Decor, floors, minor works — no services or structure guide
# Full refurbishment (mid-spec) £1,200–£2,000 per m² All-in Rewire, replumb, kitchen, bathroom, replaster, redecorate guide 1 · guide 2
# High-spec gut-out £1,800–£2,800 per m² All-in Structural changes, premium finishes guide

Extensions #

Build cost per m² and typical all-in figures for the common extension types (shell + standard finish, before kitchen and professional fees).

Item2026 rangeUnitTypeBasisSource
# Single-storey extension £1,800–£2,800 per m² All-in Standard spec, rear, flat or pitched roof guide 1 · guide 2
# Single-storey rear extension, 20 m² £36,000–£56,000 job All-in 5 m × 4 m kitchen-diner, bifolds, standard finish guide
# Two-storey extension £1,600–£2,400 per m² All-in Shared foundations/roof make it cheaper per m² than single storey guide 1 · guide 2
# Two-storey rear extension, 25 m² footprint £80,000–£120,000 job All-in 50 m² total — kitchen-diner below, bedroom + bathroom above guide
# Double/two-storey extension (all types) £55,000–£130,000 job All-in Side, rear and wraparound; £1,400–£2,900/m² combined guide
# Garden room, 4 m × 3 m insulated £12,000–£25,000 job All-in Supplied and installed; larger/high-spec £30,000–£60,000+ guide

Loft conversions #

All-in figures by conversion type; London adds 10–15%.

Item2026 rangeUnitTypeBasisSource
# Velux / rooflight conversion £22,000–£35,000 job All-in No dormer; staircase + basic fit-out guide 1 · guide 2
# Rear dormer conversion £45,000–£65,000 job All-in 3-bed semi, bedroom + en-suite, ~25 m² guide
# Hip-to-gable with dormer £55,000–£75,000 job All-in End-terrace/semi with hipped roof guide
# Full mansard £65,000–£90,000+ job All-in Max volume; usually needs planning permission · upper bound is "+" — large mansards exceed £90k guide
# Loft staircase, supply & fit £1,200–£5,500 job All-in Straight/winder softwood to space-saver/spiral; Part K guide
# Roof window (skylight), fitted £600–£1,200 per unit All-in Standard centre-pivot; fire-egress sizes at the top guide
# Dormer window incl. structure £3,000–£6,000 per opening All-in Small box dormer, structural work included guide

Basements & cellars #

Item2026 rangeUnitTypeBasisSource
# Convert an existing cellar £25,000–£50,000 job All-in Tanking, floor, services, staircase guide
# Full dig-out basement £80,000–£150,000 job All-in No existing cellar; 16–32 weeks; upper bound is "+" guide
# Basement tanking £3,000–£8,000 per 30–50 m² of wall All-in Cementitious tanking; cavity drain membranes £50–£90/m² guide

Kitchens #

Supply by spec band, plus the realistic fitting labour — which is seldom under £4,000 once plumbing, electrics, tiling and the worktop are counted.

Item2026 rangeUnitTypeBasisSource
# Budget kitchen, fitted £5,000–£10,000 job All-in Flat-pack units, laminate worktop guide
# Mid-range kitchen, fitted £12,000–£25,000 job All-in Rigid units, quartz/solid worktop, integrated appliances guide
# Premium / bespoke kitchen £30,000–£60,000 job All-in Bespoke cabinetry; upper bound is "+" guide
# Kitchen fitting labour (full: fit, plumbing, electrics, tiling, worktop) £4,000–£7,000 job Labour Standard 10–15 unit kitchen; £5,000–£9,000 in London guide
# Kitchen fitter’s labour only (units, plinths, handles) £800–£2,500 job Labour The cabinet-hanging element alone — not the whole job guide
# Kitchen island, fitted with services £4,000–£12,000 job All-in Basic unit £1,500–£4,000; with plumbing/extraction/electrics guide

Bathrooms #

Item2026 rangeUnitTypeBasisSource
# Basic bathroom renovation £3,500–£6,000 job All-in New suite, re-tiling, basic fixtures guide
# Mid-range bathroom (4–6 m²) £7,000–£12,000 job All-in Quality suite, full tiling, UFH optional guide
# Wet room / luxury bathroom £12,000–£18,000 job All-in Tanking, linear drain, premium fittings; upper bound "+" guide
# Downstairs toilet / cloakroom £2,000–£5,000 job All-in Incl. drainage connection and Building Regs guide

Structure & groundworks #

Item2026 rangeUnitTypeBasisSource
# Strip foundations £150–£250 per m run All-in Excavation + concrete guide
# Trench-fill foundations £180–£320 per m run All-in To ~1 m; deeper near trees guide
# Raft slab £80–£150 per m² All-in Excavation and concrete included guide
# Ready-mix concrete £95–£130 per m³ Materials C20 low end → C40 high end, delivered guide
# Load-bearing wall removal + steel beam, all-in £2,500–£6,500 job All-in Engineer, beam, install, padstones, making good guide 1 · guide 2
# Universal beam (UB), supply £30–£150 per m Materials S275 ex-stockholder; fabrication/galvanising +30–60% guide
# Structural engineer fees £400–£5,000 job Fees & prelims £400–£800 single beam calc → £2,500–£5,000 full loft/extension design guide
# Architect fees (extension) £3,000–£12,000 job Fees & prelims 8–15% of build cost for a small–medium project guide
# Party wall surveyor £700–£1,500 per surveyor Fees & prelims Notice is free; two-surveyor disputes double it guide
# Building Control — domestic extension or loft (plan check + inspections) £900–£1,500 job Fees & prelims Single-storey extension £900–£1,200; two-storey/loft £1,000–£1,500; rarely under £900 for a real project guide
# Building Control — minor internal work (e.g. one RSJ, re-wire notice) £300–£600 job Fees & prelims Building notice for a small single element; the statutory minimum, not a project fee guide
# Building Control — basement conversion £1,200–£2,000 job Fees & prelims More inspections (waterproofing, structure); approved inspector quotes similar guide
# Scaffolding, 3-bed semi £700–£2,200 job Fees & prelims By hire length; detached 4-bed £1,800–£3,500; +£80–£200/week guide
# Builder’s skip (6–8 yard) £180–£350 each Fees & prelims +20–40% London/SE; permit for road placement guide

Roofing #

Item2026 rangeUnitTypeBasisSource
# New roof, 3-bed semi £6,000–£14,000 job All-in Materials + labour + scaffold; by covering guide
# Concrete roof tiles, laid £80–£120 per m² All-in guide
# Natural slate, laid £130–£220 per m² All-in guide 1 · guide 2
# Flat roof — felt £40–£70 per m² All-in 10–15 yr life guide
# Flat roof — EPDM rubber £55–£95 per m² All-in 30–50 yr life guide
# Flat roof — GRP fibreglass £65–£110 per m² All-in guide

Electrics, plumbing & heating #

Item2026 rangeUnitTypeBasisSource
# Full rewire, 2-bed house £3,500–£6,000 job All-in New consumer unit, all circuits, Part P; 5–10 days guide
# Full rewire, 5-bed house £7,000–£14,000 job All-in guide
# New combi boiler, supply & fit £1,800–£3,500 job All-in Like-for-like swap; labour £400–£900 within this guide
# System boiler, supply & fit £2,200–£4,500 job All-in guide
# Wet underfloor heating, installed £60–£120 per m² All-in Radiators £150–£400 per room for comparison guide
# DPC injection, typical semi £800–£2,500 job All-in guide

Finishes & decoration #

Item2026 rangeUnitTypeBasisSource
# Plaster skim £15–£25 per m² All-in Plasterer day rate £250–£400 guide
# Decorate a room (standard repaint) £150–£400 per room Labour £400–£900 for a large room with prep; day rate £200–£300 guide
# Solid wood flooring, fitted £35–£120 per m² All-in Engineered £25–£80/m² guide
# Vinyl / LVT flooring £5–£60 per m² All-in Sheet → LVT guide
# Screed £15–£40 per m² All-in Sand-cement → liquid guide

Windows, doors & glazing #

Item2026 rangeUnitTypeBasisSource
# Replacement window, supply & fit £300–£1,500 per window All-in uPVC → timber/aluminium; FENSA guide
# Bifold doors, 2.4 m aluminium set £2,000–£5,500 set (supply) Materials £6,000–£10,000+ installed for wider spans guide
# Secondary glazing £150–£500 per window All-in Keeps original frames — listed buildings guide

Insulation #

Item2026 rangeUnitTypeBasisSource
# Loft insulation top-up to 270 mm £300–£900 job All-in DIY £300–£600; installed £400–£900 guide
# Spray foam insulation £15–£35 per m² All-in Mortgage-risk warning; removal £800–£3,000+ guide

Trade day rates #

Typical 2026 national day rates (labour only, ex VAT); London and the South East run 20–35% higher — the per-row basis shows the London band. From our tradesperson day-rates guide.

Item2026 rangeUnitTypeBasisSource
# Labourer / ground worker £150–£200 per day Labour London/SE £180–£260 guide
# General builder £180–£280 per day Labour London/SE £230–£350 guide
# Bricklayer £200–£300 per day Labour London/SE £260–£380 guide
# Carpenter / joiner £200–£280 per day Labour London/SE £250–£360 guide
# Plasterer £180–£260 per day Labour London/SE £230–£320 guide
# Painter & decorator £160–£240 per day Labour London/SE £200–£300 guide
# Plumber £200–£320 per day Labour London/SE £260–£400; £45–£80/hr guide
# Gas engineer (Gas Safe) £220–£350 per day Labour London/SE £280–£450; £50–£90/hr guide
# Electrician £220–£350 per day Labour London/SE £280–£450; £45–£80/hr guide
# Roofer £180–£280 per day Labour London/SE £230–£360 guide
# Tiler £180–£260 per day Labour London/SE £230–£320 guide
# Kitchen fitter £180–£280 per day Labour London/SE £230–£360 guide
# Bathroom fitter £200–£300 per day Labour London/SE £250–£380 guide
# Flooring fitter £160–£250 per day Labour London/SE £200–£320 guide
# Damp proofer £180–£280 per day Labour London/SE £230–£360 guide
# Scaffolder (per crew, per lift) £400–£900 per day Labour London/SE £600–£1,200 guide

Project build-ups #

Itemised materials / labour / fees build-ups for the four most common projects, assembled from the figures above. Each has its own page with every line linked.

  • Loft Conversion — £45,000–£65,000 · Rear dormer conversion on a 3-bed semi — one bedroom + en-suite, ~25 m² of floor
  • Ground Floor Extension — £36,000–£56,000 · Single-storey rear extension, 20 m² (5 m × 4 m), open-plan kitchen-diner with bifolds
  • Double Storey Extension — £80,000–£120,000 · Two-storey rear extension, 25 m² footprint (50 m² total) — kitchen-diner below, bedroom + bathroom above
  • Internal Renovation — £62,000–£122,000 · Mid-spec refurbishment of a 3-bed, 90 m² house — rewire, replumb, new kitchen & bathroom, replaster & redecorate throughout

Using these figures

You're welcome to quote this data in articles, forums and research — please credit it as "Renovation Notes UK Renovation Cost Index, August 2026" and link to renovationnotes.com/uk-renovation-cost-index. Each item has a permanent anchor (the # beside it) so you can link to a single figure. Figures are aggregated from our guides, which are researched and updated by a team of construction engineers; ranges reflect typical projects and exclude VAT where the trade is VAT-registered.