Composite Decking – cost per m² – UK 2026 Rate Guide

Budget rate for supply & lay · typical budget rate before your adjustments

Labour, plant, materials, outputs and waste — yours to edit, as an Excel. Three free.

Rates are UK national (non-London): central London and constrained urban sites typically run dearer — adjust the labour, plant and access lines in the build-up accordingly.

Composite decking

per m² · supply & lay

£141 – £264 / m²

What is it

The supply and installation of a composite (WPC) wood deck — wood-plastic-composite deck boards laid on hidden clips to falls over a treated softwood subframe (joists at ~400 mm centres, bearers and posts/pads) and a weed-control membrane, on prepared level ground — priced per m² of deck area. A capped solid WPC board is the mainstream UK garden deck; low-maintenance, splinter-free and far longer-lived than a softwood deck. This rate prices the DECK only — balustrade, steps, foundations and drainage are separate rates. The rate carries three operations:

Build the subframe — treated softwood joists set out to gauge on bearers and posts/pads over a weed membrane, levelled and fixed to a rigid braced frame set to falls.
Lay & clip — WPC composite boards loaded out, cut to size and laid on hidden stainless clips with the correct expansion gaps.
Finish off — fascia / picture-frame edge boards fitted and the deck finished to a clean, square, low-maintenance surface.

Rate range by board grade

Hollow-core uncapped£141 – £182 / m²

Solid capped WPC£165 – £213 / m²

Capped (Trex / Millboard)£205 – £264 / m²

Budget rate per m².

3 key cost drivers

Deck complexity & height

A simple ground-level rectangular deck on prepared level ground is fastest; a raised deck on posts & pads, a cut-up plan, steps, fascia and a picture-frame border add subframe and cutting time. It is a key driver of the labour per m².

Board type & grade

Three genuinely different board products: a hollow-core uncapped board, a solid capped WPC board (the default) and a capped composite (Trex / Millboard class). Each is a distinct BoQ item — different product, different unit price — so the control switches product, not price grade.

Location

London and the South East typically add around 20% to labour.

Estimator

Budget rate generator

Board type & grade

£165 – £213 / m²

Covers the treated softwood subframe, WPC composite boards, hidden fixings, membrane, the fitting gang and O&P · excl. balustrade, steps, foundations, lighting, drainage, scaffold & VAT

Exclusions

Lifting & material distribution — telehandler / forklift, hoist and site-distribution labour (an attendance, in main-contractor prelims)
Balustrade / handrails, steps, pergolas and deck lighting
Groundworks / foundations beyond simple pads, surface-water drainage, structural design and access / scaffold
Scaffold supply (usually in preliminaries)
Preliminaries — main-contractor site set-up, management & welfare
VAT