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 £2,000–£3,000 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–£3,000 per m² All-in Standard spec, rear, flat or pitched roof guide 1 · guide 2
# Single-storey rear extension, 20 m² £36,000–£60,000 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) £63,000–£155,000 job All-in 40 m² over two floors, Midlands/North to London & South East; about £1,575–£3,875/m² guide
# Garden room, 4 m × 3 m insulated £13,000–£28,000 job All-in Supplied and installed, plus VAT; larger/premium £30,000–£90,000+ guide

Loft conversions #

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

Item2026 rangeUnitTypeBasisSource
# Velux / rooflight conversion £25,000–£38,000 job All-in No dormer; staircase + basic fit-out guide
# 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 £8,000–£15,000 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; 20–40 weeks; upper bound is "+" guide
# Basement tanking £2,500–£8,000 small cellar to complex basement All-in Cementitious tanking; cavity drain membranes £35–£90/m² plus sump 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 £2,500–£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 £2,300–£6,100 job All-in Engineer, beam, install, padstones, making good guide
# Steel beam supplied and installed, before making good £2,060–£5,640 job All-in Beam, props, padstones, engineer and building control; plasterboard encasement only guide
# Universal beam (UB), supply £30–£155 per m Materials S275 ex-stockholder, about £1.85–£2.90/kg guide
# Structural engineer fees £400–£6,000 job Fees & prelims £400–£800 single beam calc; £700–£3,000 loft or extension package; basements £2,500–£6,000+ 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–£1,200 per surveyor Fees & prelims Notice is free; two-surveyor disputes double it guide
# Dropped kerb (vehicle crossing construction) £1,575–£3,050 crossing Fees & prelims Highway authority construction charge, standard domestic crossing; Manchester from £1,575, Norfolk county average about £3,050 (Wandsworth £2,311) 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 25–50 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 £3,000–£5,000 job All-in System boiler with a cylinder, mid-range guide
# Wet underfloor heating, installed £60–£120 per m² All-in Radiators £150–£400 per room for comparison guide
# DPC injection, typical semi £900–£2,500 job All-in guide

Finishes & decoration #

Item2026 rangeUnitTypeBasisSource
# Plaster skim £8–£18 per m² All-in Plasterer day rate £200–£350 (£280–£450 London and South East) 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 £55–£120 per m² All-in Engineered £40–£90/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 £2,200–£4,000 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 £120–£700 job All-in DIY £120–£350; installed £300–£700 guide
# Spray foam insulation £15–£35 per m² All-in Mortgage-risk warning; removal £1,200–£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 £250–£300 per day Labour London/SE £290–£340 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, September 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.

How each figure is built, from merchant list prices, labour times and day rates, and how its source is graded, is set out in how Renovation Notes prices its figures. Treat every range as a ballpark for budgeting, not a quote: how cost estimates work explains how far each level of estimate can miss, and why early figures tend to come in low.