Composite Decking Cost per m²: Boards, Frame and Fixings
A composite deck costs {cost:deck-building:mid} for our 25 m² default. See how frame, height and steps change that, and how it compares with timber.
A composite deck of 25 m² typically costs £3,800, fitted and including VAT, and the usual range for a mid-tier deck is £2,200 – £3,650. Divide by 25 for a rough per-m² price. Treated softwood and hardwood come out differently, and the extras you add change the total more than the choice of board does.
What the price covers
Our figures are built the way a builder would price the job: labour hours × local rates, plus materials, checked against market prices and real quotes. A composite deck price has four parts:
- Boards: composite is the dearest part of the material bill, but it needs no staining or oiling.
- Sub-frame: treated timber joists on adjustable pedestals or footings. This is where cheap quotes often cut corners.
- Fixings: hidden clips, screws, end caps and trims. Composite uses more specialist fixings than timber.
- Groundwork: levelling, weed membrane and drainage, which depend on your site.
If a quote shows only "boards per m²", it leaves out the frame and fixings, so it isn't comparable with ours.
Composite against softwood and hardwood
The table below shows typical cost, usual range and lifespan for each material on the same default deck.
| Material | Typical | Usual range | Lifespan |
|---|---|---|---|
| Treated softwood | £2,800 | £2,200 – £3,650 | 10-15 years |
| Composite | £3,800 | £2,950 – £4,950 | 25-30 years |
| Hardwood (balau, ipe) | £4,150 | £3,250 – £5,400 | 20-25 years |
In short:
- Composite: £3,800
- Treated softwood: £2,800
- Hardwood (balau, ipe): £4,150
The gap between these is smaller than many people expect once you remember what timber needs afterwards. Softwood should be left to dry out and then oiled or stained, which is a cost and a recurring chore. Composite needs no finish. We treat that finish as a separate option, so check whether a softwood quote includes it. Our figure for oiling or staining new timber is £3,350. That is the total for a deck with that option chosen, not an extra on top.
Where composite decks get more expensive
Raised decks
A deck at ground level is the cheapest case. Raising it off the back door, up to about 2 m, needs taller posts, bracing and usually a rail. A raised composite deck comes to £3,750, set against the same deck at ground level.
Railings and steps
Both are priced as options in our model:
- Timber railing: £4,250
- A full flight of stairs with handrail: £3,200
A raised deck almost always needs both, so compare quotes on the same basis. Ask whether the stair stringers, handrail and balustrade are in the price.
Removing an old deck
Taking up and disposing of a tired deck is a job in its own right. With removal included, the total is £3,250. Many quotes leave it out and add it later.
Do you need planning permission?
Most gardens are fine. Our fact sheet says decking or other raised platforms are permitted development (no planning application) if:
- it is no more than 30 cm above the ground;
- together with other extensions, outbuildings and so on, it covers no more than 50% of the garden;
- none of it is forward of the wall forming the principal elevation.
There are additional limits in National Parks, AONBs, conservation areas and World Heritage Sites, and for listed buildings. This matters for raised decks. A deck higher than 30 cm may need a planning application, so check with your council before you order.
How to compare quotes
- Match the specification. Same area, same height, same board type, same finish.
- Check what is under the boards. Ask about frame material, joist spacing and ground preparation.
- List the extras. Steps, rail, removal, lighting and any gate should each be itemised.
- Ask about the guarantee. Boards and workmanship are usually guaranteed separately.
If you already have a price, our "is my quote fair" tool checks it against the live model for your region.
Is composite worth it?
Composite makes sense if you want low maintenance and a consistent look, and you will keep the deck for many years. Treated softwood is the better choice on a tight budget or for a short-term fix. Hardwood suits those who want a natural finish and will accept the upkeep. For the full breakdown by size, region and option, see our Garden decking guide.
If the deck is part of a wider garden project, you may also want to price the boundary. Our Fencing guide covers panels, posts and gates, and our New driveway guide covers the surface and drainage for the front.
Our figures include 20% VAT. The 0% VAT relief on energy-saving materials does not apply to decking.