Composite decking cost: UK homeowner's 2026 guide

Fully installed composite decking in the UK typically costs between £150 and £350 per m², supply and fit combined, depending on board grade and site complexity. A standard 15m² deck comes in at around £1,260 on average, while a 20m² project at mid-range specification usually costs a few thousand pounds, with variation depending on specifics. Most straightforward installations take 1–3 days with a two-person crew. The three biggest variables are board grade (hollow uncapped versus capped solid), subframe specification, and whether the site is ground-level or raised. Deck Kingdom supplies boards, accessories, and balustrade kits across the UK, with free samples available so you can check quality before committing to a budget.

Quick cost signposts:

Supply-only boards: roughly £37–£92 per m² depending on grade
Fully installed (supply + subframe + fixings + labour): £150–£350/m²
15m² example total: approx. £1,260–£3,500
20m² example total costs are generally within a broad range depending on materials and complexity
Install time: 1–3 days for most domestic decks
Main cost drivers: board type, subframe material, site access, regional labour rates

Key takeaways

Fully installed composite decking in the UK costs £150–£350 per m² depending on board grade and site complexity, with a typical 15m² deck averaging around £1,260 and a 20m² mid-range project landing between £3,000 and £5,000.

Point	Details
Installed cost range	Expect £150–£350 per m² fully installed; supply-only boards run £37–£92 per m² by grade.
Biggest cost drivers	Board grade, subframe specification, and regional labour rates move the total most.
Lifetime value	Composite typically costs less than timber over 20 years once maintenance and replacement are included.
Subframe quality	Correct joist spacing (300–400mm) and treated or composite joists protect your investment long-term.
Deck Kingdom	Supplies boards, accessories, and balustrade kits with free samples and nationwide UK delivery.

How much does composite decking cost per m²?

Supply-only composite decking ranges from roughly £37 to £92 per m² by board grade, and fully installed projects commonly sit between £150 and £350 per m². The gap between those two figures is where subframe, fixings, and labour live.

The table below shows worked totals for four common deck sizes. Regional labour rates vary: London and the South East typically run higher than the North West, Midlands, and Yorkshire.

How the 20m² mid-range figure is reached: boards at £50–£80/m² = £1,000–£1,600; subframe timber and fixings add roughly £400–£600; labour for a two-person crew over 2–3 days adds £600–£900. Total: approximately £2,000–£3,100 at the lower end, rising to £5,000 with premium boards and a more complex site.

Mid-range composite boards commonly sit at £50–£80 per m² supply-only and premium boards at £80–£120 per m², so the board choice alone can shift a 20m² project by £800–£1,000 before a single joist is cut.

Assumptions used throughout this guide:

VAT at 20% included in all fully installed figures
Standard ground-level treated timber subframe, joists at 400mm centres
Two-person crew, standard domestic access
No skip hire, old-deck removal, or groundwork unless stated
Mid-range figures use £50–£80/m² boards; premium uses £80–£120/m²

What board type you choose changes the price significantly

The composite decking market broadly splits into five board categories, each with a different supply-only price band and a different performance profile.

Hollow uncapped boards are the entry point, typically £37–£50/m². The hollow core reduces weight and cost, but the open profile can absorb moisture and staining over time. Fine for a sheltered, low-traffic area.

Hollow capped boards sit at roughly £50–£70/m². A protective polymer shell wraps the board on two or four sides, adding scratch, stain, and UV resistance without the weight of a solid board. A popular mid-range choice for most domestic gardens.

Solid uncapped boards run £50–£75/m² and feel more substantial underfoot, which some homeowners prefer. Without a cap, they share the same surface vulnerability as hollow uncapped boards.

Solid capped boards are the premium workhorse at £70–£92/m² and above. Four-sided co-extrusion gives the best protection against fading, staining, and moisture ingress. Worth the premium for pool surrounds, south-facing terraces, or any deck that sees heavy foot traffic year-round.

Full PVC boards sit at the top of the range, often £90–£120/m² supply-only. They contain no wood fibre, so moisture is a non-issue, but they can feel less natural underfoot and expand more noticeably in heat.

For a 15m² deck, upgrading from hollow uncapped to solid capped boards typically adds £500–£650 to supply costs alone. Whether that premium is worth it depends on how much sun and traffic the deck receives.

Quick pros and cons by category:

Hollow uncapped: lowest cost, lighter weight; less durable surface, can stain
Hollow capped: good balance of cost and protection; check cap thickness (2mm+ is better)
Solid uncapped: solid feel; surface still vulnerable without a cap
Solid capped: best all-round durability; highest supply cost in the composite range
Full PVC: moisture-proof; higher thermal expansion, premium price

Pro Tip: Ask your supplier for the cap thickness specification in millimetres. A 2mm co-extruded cap outperforms a thin 0.5mm laminate cap in scratch resistance and will hold its colour noticeably longer in direct sun.

What you’re paying for: labour, subframes, and installation time

Understanding what drives those costs helps you read quotes critically.

Typical installer day rates in the UK run from around £200–£300 per person per day, with London and the South East at the upper end. A two-person crew on a standard 15–20m² ground-level deck usually completes the job in 2–3 days, so labour alone can add £800–£1,800 depending on location and complexity.

What a professional installation price should cover:

Site survey and setting out
Subframe construction (joists, bearers, fixings)
Board laying and hidden clip fixing
Perimeter trim and end cap fitting
Basic levelling and ground preparation
Waste removal of off-cuts (though skip hire for old decking is usually extra)

Subframe options and their cost impact

The subframe is the skeleton under your boards, and it is the most common point of long-term failure if specified poorly. Treated timber joists are the standard choice and the cheapest, adding roughly £15–£25/m² to material costs. Composite joists cost more but resist rot and moisture better. Aluminium subframes carry a significant material premium but are recommended for raised decks or areas prone to standing water, where differential expansion and rot risk are higher.

Composite installations often require closer joist spacing of 300–350mm compared with the 400–600mm typical for timber decking. That tighter spacing means more joists, more fixings, and more labour time, which is why the installed cost per m² for composite is higher than the board price alone suggests.

Pro Tip: When reviewing a quote, check that the joist spacing is specified in writing. A quote that lists “standard subframe” without stating centres could mean 600mm spacing, which is too wide for most composite boards and will cause flex underfoot within a year or two. Ask for 300–400mm centres as a minimum.

Statistic callout: Most straightforward domestic composite deck installations take 1–3 days with a two-person crew. A 30m² deck or one with a raised section, steps, or difficult access can extend that to 4–5 days.

Extra costs that often catch homeowners by surprise

The per-m² figures above cover boards, subframe, and labour for a flat ground-level deck. Several common additions can push the final bill well beyond those totals.

Balustrades and handrails are required by Building Regulations for any deck more than 600mm above ground level, and they add meaningful cost. A basic composite balustrade kit typically runs £80–£150 per linear metre supplied, with installation adding £30–£60 per metre on top. A glass balustrade is a popular premium upgrade; planning a glass railing on composite decking requires specific post-fixing methods and adds further material cost, but the visual result is hard to match. For a 5-metre run, budget £550–£1,050 for composite balustrade supply and fit, or more for glass.

Steps add £150–£400 per flight depending on width, material, and whether they are built from composite or timber. A single two-step flight in matching composite boards sits at the upper end of that range.

Ground preparation and foundations vary enormously. A flat, firm garden may need only weed membrane and gravel; a sloped or soft site may require concrete pads or a full concrete base, adding £500–£2,000 or more.

Skip hire and old-deck removal are rarely included in a standard quote. Skip hire runs roughly £200–£400 depending on size and location. Removing and disposing of an existing timber deck typically adds £150–£300 in labour.

Integrated lighting is a popular upgrade. Recessed deck lights cost £20–£60 per fitting supplied, with wiring adding to the electrician’s bill. Budget £300–£800 for a modest lighting scheme on a 20m² deck.

Planning permission is not usually required for a ground-level deck below 300mm in height, but decks above 300mm, those attached to a listed building, or those in a conservation area may need consent. Always check with your local planning authority before starting work.

Checklist of extras to include in your initial quote request:

Balustrade or handrail (specify height and linear metres)
Number of steps and preferred material
Ground preparation required (level, slope, existing surface)
Old deck or surface removal and disposal
Lighting (number of fittings, power source)
Drainage or falls required for water run-off

Is composite decking cheaper than timber over its lifetime?

Composite decking costs more upfront than treated softwood, but the lifetime picture is more balanced than the initial price gap suggests. Composite decking is more expensive than softwood upfront, but its much lower routine maintenance and longer practical lifespan often make total cost over 10–20 years comparable or better than timber.

A treated softwood deck for a 20m² area might cost £1,500–£2,500 fully installed. Annual maintenance (oiling, staining, sanding, and the occasional board replacement) typically adds £150–£300 per year. Over 15 years, that maintenance spend alone can reach £2,250–£4,500, and most softwood decks need partial or full replacement within 10–15 years.

A mid-range composite deck on the same 20m² area costs £3,000–£5,000 installed. Annual maintenance is minimal: a periodic clean with a brush and mild detergent, costing perhaps £30–£60 in time and materials per year. Most quality composite boards carry 10–25 year warranties covering fade and structural integrity.

What to check in a composite warranty:

Does it cover fade and colour change, or structural failure only?
Is the warranty transferable if you sell the property?
What maintenance is required to keep the warranty valid?
Does it cover the full board or only the cap layer?

Over 20 years, the composite deck’s total cost (installation plus minimal maintenance) often comes out comparable to or lower than the timber alternative once you account for timber’s repainting, oiling, and eventual replacement. The decking maintenance process for composite is genuinely straightforward: an annual clean is usually all that is needed to keep boards looking good and the warranty intact.

Composite vs timber: 20-year cost comparison for a 20m² deck

Cost element	Treated softwood	Mid-range composite
Initial installation	£1,500–£2,500	£3,000–£5,000
Annual maintenance cost	£150–£300/yr	£30–£60/yr
20-year maintenance total	£3,000–£6,000	£600–£900
Likely replacement cost (after 10 years)	£1,500–£2,500	None (within warranty)
20-year total	£6,000–£11,000	£3,600–£6,200

Composite wins on lifetime cost for most homeowners who plan to stay in the property for more than a decade. The 25-year durability guide for decking boards from Deck Kingdom explains how board selection affects that lifespan in practical terms.

How to get an accurate quote for your composite deck

A vague quote is almost always a problem waiting to happen. Here is how to measure up, brief your installer, and compare bids properly.

Measurement checklist:

Measure the deck area in metres (length × width), then add 10% for cutting waste
Note any irregular shapes, cut-outs around posts, or curved edges
Record the height difference between the deck surface and ground level at each corner
Note the distance from the nearest access point (gate width, staircase, path width)
Identify any underground utilities (gas, water, electric) that may affect foundation work
Measure the perimeter that will need balustrade or edging trim

Specification items to request in every quote:

Board product name, grade, thickness, and cap type
Subframe material and joist spacing (in millimetres)
Fastener type (hidden clip or face-fix screw)
Warranty terms (years, what is covered, transferability)
Whether delivery and waste removal are included
Payment schedule and start date

Red-flag questions to ask any installer:

“Can I see a written, itemised quote?” (No written quote = walk away)
“What joist spacing will you use?” (Anything above 400mm for composite = too wide)
“How will you ventilate under the deck?” (No answer = potential rot risk)
“Is the subframe treated or untreated timber?” (Untreated = short lifespan)

Deck Kingdom’s composite decking installation guide sets out the technical standards you should expect from any professional installer, and it is worth reading before you invite quotes.

Numbered checklist to copy into your quote request email:

Deck dimensions (length × width in metres, plus any irregular sections)
Height above ground at each corner
Board specification required (grade, cap type, colour)
Subframe material and joist spacing
Balustrade requirement (yes/no, linear metres, height)
Number of steps
Ground preparation needed
Old surface removal required (yes/no)
Lighting or drainage requirements
Preferred start date and expected duration

How these figures were calculated

The price ranges in this guide draw on published UK cost guides, online calculators, and Deck Kingdom’s own product and pricing signals. The primary external sources are the BOHAI 2026 composite decking cost guide, MyJobQuote’s installation cost data, Costwise’s decking calculator, BookaBuilderUK’s 2026 garden deck price guide, Squote’s decking installation pricing guide, and NeverMow UK’s 2026 composite decking cost guide.

Core assumptions used in all worked examples:

VAT at 20% included in all fully installed totals
Two-person crew at standard UK day rates (£200–£300 per person per day)
Ground-level deck with standard domestic access
Treated timber subframe, joists at 400mm centres (unless stated otherwise)
No skip hire, old-deck removal, or groundwork unless explicitly noted
Mid-range boards: £50–£80/m² supply-only; premium boards: £80–£120/m²

Regional variation is real. Mid-range fully installed composite projects in 2026 commonly cost £100–£200 per m², with the North West, Midlands, and Yorkshire typically at the lower end and London and the South East at the upper end. Add 15–25% to labour estimates for London projects.

Composite boards typically add £50–£120 per m² over a basic softwood option, which is why the installed cost gap between composite and timber is smaller than the board price alone implies once you factor in the shared subframe and labour costs.

Deck Kingdom’s company information is publicly available via Companies House record 08530988, and its product range, pricing signals, and installation resources are published at deckkingdom.co.uk.

A practical perspective on where to spend and where to save

The single most common mistake homeowners make when budgeting for composite decking is specifying a premium board on a budget subframe. The board is what you see; the subframe is what determines whether the deck is still performing in 15 years.

Mid-range capped boards paired with a correctly spaced, treated timber subframe will outperform premium boards on a poorly spaced or ventilated frame every time. If budget is tight, choose a solid capped board at the mid-range price point and spend the saving on getting the subframe right: correct joist spacing (300–400mm), adequate ventilation gaps, and treated timber or composite joists. That combination gives you the best long-term return.

Deck Kingdom offers free samples of its composite board range, so you can check colour, texture, and weight before committing. Nationwide delivery means you are not limited to what a local merchant stocks, and the installation guides and tutorials give you the technical grounding to brief an installer confidently or tackle a DIY project with clear steps.

Deck Kingdom’s composite decking range: from first sample to finished deck

Deck Kingdom supplies the full range of materials you need to budget and build a composite deck: boards in hollow and solid capped profiles, composite decking accessories including hidden clips, trims, and end caps, and composite balustrade kits for decks that need a railing. Free samples are available so you can check colour and texture at home before ordering. All products are available for nationwide delivery or click-and-collect at the Manchester showroom.

For a first quote, the most useful accessories to price alongside your boards are hidden fixing clips, perimeter trim, and end caps. These are often overlooked in early budgets but are needed to finish the deck properly. You can browse the full decking accessories range and request a free sample at deckkingdom.co.uk, or use the step-by-step installation tutorial to prepare your specification before inviting contractor quotes.

Sources

FAQ

How much does a 20m² composite deck cost in the UK?

A 20m² composite deck typically costs £3,000–£5,000 fully installed at mid-range specification, rising to £5,000–£7,000 with premium capped boards. Supply-only boards for 20m² run roughly £1,000–£1,600 depending on grade.

How much does a 15m² composite deck cost supply and fit?

A 15m² deck fully installed averages around £1,260 at the lower end of the market, with mid-range projects typically landing between £2,250 and £3,750 once subframe, fixings, and labour are included.

What should I expect to pay per m² for composite decking?

Supply-only composite boards range from roughly £37 to £92 per m² by grade. Fully installed, most mid-range projects cost £150–£200 per m², with premium specifications reaching £300–£350 per m².

Is composite decking cheaper than timber in the long run?

Yes, for most homeowners who keep a deck for 10 years or more. Timber’s annual maintenance costs and likely replacement within 15 years mean a 20m² timber deck can cost £6,000–£11,000 over 20 years, compared with £3,600–£6,200 for a comparable composite deck.

How long does composite decking take to install?

Most straightforward domestic composite decks take 1–3 days with a two-person crew. Larger decks (30m²+), raised structures, or sites with difficult access can extend the job to 4–5 days.

CLEARANCE!!

Composite decking cost: UK homeowner’s 2026 guide