Board material
Softwood timber is usually the lower-cost option. Hardwood and composite decking cost more because the boards, fixings and finish expectations are higher.
Decking cost calculator
Decking Cost Calculator UK
Estimate the cost of UK garden decking using deck area, board material, deck height, ground condition, finish level and region. Compare softwood, hardwood, composite and premium composite decking costs.
Why decking costs vary
Decking is part surface and part structure. The boards are the visible finish, but the frame, supports, height and ground condition often decide the real quote.
Subframe and supports
The frame carries the load. Raised decks, sloped gardens and high-use areas need stronger support than a simple ground-level deck.
Height and ground condition
A flat garden is easier to work with. Slopes, old decking, poor ground or a high deck can add labour, structure, steps and safety details.
Compare decking materials
The best decking material depends on budget, maintenance, appearance and how exposed the deck will be.
| Material | Typical cost behaviour | Best suited to |
|---|---|---|
| Softwood timber | Usually lower upfront | Budget decks, simple garden seating areas and lower-spec projects |
| Hardwood timber | Higher material cost | Natural timber appearance and longer-lasting boards |
| Composite decking | Mid to higher range | Lower maintenance, modern finishes and family garden spaces |
| Premium composite | Higher range | Design-led decks, premium finishes and higher-spec outdoor areas |
| Not sure | Wider estimate range | Early budgeting before choosing timber or composite boards |
If you are still choosing between hard surfaces, compare this with the Patio Cost Calculator. If decking is only one part of the garden, use the Garden Landscaping Cost Calculator.
Typical UK decking cost ranges
These ranges are broad planning figures. Use the calculator above for a more specific estimate based on deck area, material, height, ground condition and region.
| Decking project | Typical range | Cost pattern |
|---|---|---|
| Small softwood deck | £1,500–£3,500+ | Lower material cost, but setup and fixings still matter |
| Standard timber deck | £3,000–£7,000+ | Size, frame and finish level drive cost |
| Composite deck | £4,000–£10,000+ | Higher board and fixing cost |
| Raised deck with steps | £6,000–£18,000+ | Structure, height and safety details drive cost |
| Premium composite deck | £8,000–£25,000+ | Board quality, subframe, edging and finish detail drive cost |
What affects decking installation cost?
The final quote depends on what you walk on, what supports it and how difficult the ground is below it.
Deck size
Larger decks cost more overall. Small decks can still have a higher cost per m² because setup, delivery and labour minimums still apply.
Decking material
Softwood, hardwood, composite and premium composite boards all have different material costs, fixing systems and maintenance expectations.
Subframe
The subframe affects strength, lifespan and labour. A deck with a poor frame can fail even if the boards look good at first.
Deck height
Raised decks need more support than ground-level decks. Steps, posts and guarding can increase both material and labour cost.
Ground condition
Slopes, soft ground, old decking, old paving and poor drainage can all increase preparation and support work.
Finish detail
Picture-frame edging, hidden fixings, lighting allowance, trims and premium boards can increase the final quote.
The hidden cost layer: frame, supports and safety
The boards are only the visible surface. A deck needs a stable frame, correct supports, suitable fixings and enough ventilation below the boards.
Raised decks can need posts, steps and guarding. Wet ground below decking can shorten lifespan, especially where ventilation is poor or water has nowhere to go.
If the garden holds water, check the Garden Drainage Cost Calculator. If the deck sits beside a level change or retained area, compare the project with the Retaining Wall Cost Calculator.
Already have a decking quote?
A decking quote should make clear what type of boards are included, what subframe is being used, whether posts or supports are required, and whether steps, balustrades, trims, fixings, removal of old decking, waste disposal and VAT are included.
If the deck is part of a wider garden project, check the decking within your full garden landscaping budget so the raised surface does not take too much of the total spend.
Decking or patio?
Decking can work well on raised, uneven or sloped parts of a garden. A patio is often better suited to flatter ground where excavation, sub-base and drainage can be handled cleanly.
A simple ground-level softwood deck may cost less than some patio options. Composite decking, hardwood decking or raised decking can cost more than a standard patio because the frame, supports and finish level add cost.
If you are comparing the two, use the Patio Cost Calculator beside this estimate before deciding which surface suits the garden.
Planning decking with the rest of the garden?
A deck often sits beside lawn, fencing, planting or a patio. If you are still deciding the whole layout, compare this estimate with the Turf Installation Cost Calculator, Artificial Grass Cost Calculator and Fencing Cost Calculator.
If the deck follows building work, compare the outdoor budget with the extensions cost calculators. For wider water issues, use the Drainage Installation Cost Calculator.
How this decking estimate is calculated
The calculator starts with a typical cost per m² for the selected decking material, then adjusts the estimate using deck height, ground condition, finish level and region. A 12% planning allowance is included automatically to keep the form quick to use.
This approach reflects the main reasons decking quotes change: board type, subframe, supports, ground condition, height and regional labour cost.
For more detail, read our methodology, pricing data and how costs are calculated.
Decking decision paths
Use these paths to move from a decking estimate to the next most useful calculator.
I want a standalone deck
Use this Decking Cost Calculator to estimate the boards, frame, structure and likely installation range.
I am choosing between decking and patio
Compare this result with the Patio Cost Calculator before choosing the surface.
I am redesigning the whole garden
Use the Garden Landscaping Cost Calculator to combine decking, patio, lawn, fencing, drainage and retaining work.
I have a wet or shaded area
Check the Garden Drainage Cost Calculator, especially if water sits below the planned deck area.
I want lawn beside the deck
Compare natural turf with artificial grass using the Turf Installation Cost Calculator and Artificial Grass Cost Calculator.
I also need fencing or privacy
Use the Fencing Cost Calculator to estimate boundary work alongside the deck.
Decking cost FAQs
How much does decking cost in the UK?
A small simple softwood deck may cost around £1,500 to £3,500+, while larger composite, hardwood or raised decks can cost £4,000 to £18,000+.
What is the average decking cost per m²?
Decking cost per m² depends on the material, subframe, deck height and installation detail. Raised composite decking usually costs more than ground-level softwood decking.
Is composite decking more expensive than timber?
Usually, yes. Composite decking tends to cost more upfront than softwood timber because the boards and fixings are higher specification.
Why is raised decking more expensive?
Raised decking needs more structure, support, posts, steps and sometimes balustrades. These items increase both material and labour cost.
Is decking cheaper than a patio?
Sometimes. A simple ground-level softwood deck may be cheaper than some patios, while composite or raised decking can cost more.
Does decking need drainage underneath?
Decking needs water management and ventilation. Wet ground under decking can shorten lifespan, especially where the frame stays damp.
Can I build decking over an old patio?
Sometimes, if the old patio is stable, levels work and drainage is suitable. The frame still needs proper support and ventilation.
Are CostIntel decking estimates fixed quotes?
No. They are planning estimates based on typical UK decking cost drivers. An installer needs to inspect the site before giving a fixed quote.