How Much Does Decking Cost in the UK? A 2026 Guide

For a standard raised timber deck in the UK in 2026, budget roughly £120–£200 per square metre supplied and fitted for pressure-treated softwood, and £200–£350 per square metre for composite. Doing the labour yourself takes a big chunk out of that, because on most decks labour is close to half the bill.

Split into materials only, softwood decking boards and the treated timber substructure together tend to land around £60–£110 per square metre, with composite boards pushing the materials figure to £120–£220 per square metre on their own. The spread inside each band is mostly about the frame: a deck sitting a few centimetres off a patio costs far less to build than a raised deck on posts with steps and a balustrade.

Takeaway: think £120–£200 per m² fitted for softwood and £200–£350 per m² for composite, with the substructure and height driving most of the variation.

Pressure-treated softwood is the default and the cheapest way to a finished deck. It's widely stocked, easy to work, and a competent DIYer can build with it. The catch is upkeep: softwood needs cleaning and re-oiling most years and will still weather, cup and eventually rot, so its low purchase price comes with a maintenance bill and a shorter life.

Composite boards, made from wood fibre and recycled plastic, cost roughly two to three times as much per board but ask for almost nothing afterwards — no oiling, no staining, just an occasional wash. Over fifteen or twenty years the total-cost gap narrows sharply, and for many people the "never sand and oil it again" factor decides it before the spreadsheet does. Hardwood decking such as balau sits above softwood and below premium composite on price and looks superb, but it's heavy, hard to fix and needs oiling to hold its colour.

Takeaway: softwood is cheapest to buy and dearest to maintain; composite is dear to buy and cheap to keep. Choose on how long you'll keep the deck and how much weekend maintenance you'll actually do.

A finished deck is three costs stacked together: the boards you see, the substructure you don't, and the labour to build it. On a fitted softwood deck the boards are often only a third of the total. The joists, bearers, posts, joist hangers, coach screws and decking screws underneath make up a substantial materials line of their own, and the labour to dig, set posts, build a level frame and fix every board down is frequently the single biggest number on the quote.

That's why comparing quotes on board price alone is a trap. A cheap board on a poorly built frame is a deck that moves and rots at the joists within a few years. The frame is the part that decides whether the deck lasts, and it's the part homeowners can't see once the boards go on, which is exactly why it's the corner most often cut.

Takeaway: boards are roughly a third of a fitted deck; the hidden frame and the labour are the rest, so never compare decks on board price alone.

Take a common job: a 20 m² (about 5 m × 4 m) deck, raised a little over a patio, built in pressure-treated softwood, fitted by a two-person crew.

Boards. Standard UK decking boards are 144 mm wide with a fitted coverage of about 150 mm once you allow a small gap, so you need roughly 6.7 linear metres of board per square metre of deck. For 20 m² that's about 134 linear metres, plus 10% for cuts and waste, so call it 148 m. At typical 2026 merchant prices of around £4–£6 per 3.6 m board from Travis Perkins or Jewson, that's roughly £240–£360 in boards.

Substructure. Treated 47 × 100 mm joists at 400 mm centres, bearers, a few posts, plus hangers and screws, come to somewhere around £250–£400 for a deck this size.

Materials total: roughly £500–£750, or about £25–£38 per m² in materials for the softwood build.

Labour. A two-person crew typically takes two to three days on a raised 20 m² deck, and supply-and-fit decking labour runs around £60–£120 per m². That's £1,200–£2,400 on top.

Fitted total: somewhere around £1,700–£3,150 for the softwood deck, or roughly £85–£160 per m² all in. Swap to composite boards and the materials line alone climbs by £1,500–£3,000, lifting the fitted total well past £4,000.

Takeaway: a fitted 20 m² softwood deck is broadly £1,700–£3,150; do the labour yourself and you're closer to the £500–£750 materials figure plus your weekends.

Three factors swing the number most. Height off the ground is the big one: a ground-level deck on a firm base is quick, while a raised deck needs posts, footings, more frame and often a balustrade, which multiplies both materials and labour. Board choice sets the materials floor, with composite two to three times softwood. And ground decides the substructure: soft, sloping or waterlogged ground means concrete footings and levelling that a flat, firm patio simply doesn't.

Extras add up faster than people expect. Steps, a balustrade, fascia boards, integrated lighting and a fixed screen each add materials and hours. A plain rectangular deck low to the ground is the cheap end of every quote; anything with a level change or a rail is not.

Takeaway: height, board type and ground conditions move the cost most, and every step, rail or light on top is a real line, not a rounding error.

Decking usually falls under permitted development in England, but not always. It counts against the rule that a raised platform must be no more than 300 mm above ground level to be automatically permitted; go higher and it can need planning permission, especially if it overlooks a neighbour. Decking also counts towards the 50% limit on the area of your garden that can be covered by buildings and hard surfaces under permitted development. Listed buildings, conservation areas and flats have tighter rules, and Scotland, Wales and Northern Ireland set their own. It's a five-minute call to your local planning authority and a lot cheaper than tearing a deck down.

Takeaway: keep a deck at or below 300 mm and inside the 50% garden-coverage limit to stay in permitted development, and check first if it's raised or overlooks anyone.

In practice, experienced UK deck builders spend their money under the deck, not on top of it. They'll happily fit a mid-range board on a frame built from properly treated C16 or C24 timber at 400 mm centres with generous ventilation beneath, because they know the frame is what fails first and the boards are the easy part to replace later. A joiner quoting a deck will almost always price a weed membrane and a gap under the boards for airflow, because a deck that can't breathe rots from the joists up regardless of what you paid for the surface.

The other quiet decision is fixings. Cheap decking screws rust and stain the boards within a season; the good builders use stainless or coated decking screws and treat every cut end of timber with end-grain preserver before it goes down, because the saw cut exposes the untreated core that the pressure treatment never reached. Neither shows up in a headline quote, and both are why one £2,000 deck lasts fifteen years and another lasts five.

Takeaway: the money that makes a deck last goes into the frame, ventilation and fixings — the parts you can't see — so read a quote for what's under the boards, not just the board name.

Cost per square metre gets you a ballpark, but boards, joists and screws come in real quantities with real waste. To turn your exact deck size into a board count, joist count and fixings list, use the Decking Area Calculator. For the frame timber and its cost, the Timber Calculator works out lengths and board feet, and if your deck sits on posts set in concrete, the Concrete Volume Calculator sizes the footings.