Deck Cost Calculator — Materials, Labour & Total Budget

Estimate the total cost to build a timber or composite deck — including decking boards, joists, posts, concrete footings, fixings and optional labour costs. Get a breakdown by material category so you know where the budget goes.

How the deck cost calculator works

  • 1Material quantities calculated from deck dimensions (same as deck board + footing calculators)
  • 2Unit prices applied to each material: boards (per lm), joists (per lm), posts (each), concrete (per bag)
  • 3Fixings estimated at 3–5% of total material cost
  • 4Labour: optional input — typical rate for deck framing is 6–8 hours per m² for professional installation
  • 5Contingency: recommend adding 10–15% to final total for unexpected items
  • 6Total cost = materials + fixings + labour + contingency

Worked example

20 m² ground-level timber deck. Example pricing: boards €8/lm, joists €4/lm, posts €20 each, concrete €5.50/bag.

Boards: 188 lm × €8 = €1,504. Joists: 88 lm × €4 = €352. Posts: 9 × €20 = €180. Concrete: 10 bags × €5.50 = €55. Total materials: €2,091 + 10% contingency = €2,300. Adjust unit prices to match your local quotes.

Frequently asked questions

How much does it cost to build a deck?

A basic pressure-treated timber deck typically costs €150–250/m² for materials plus labour. Composite decking adds 50–100% to material costs but requires less maintenance. Complex raised decks or those requiring permits cost more. Prices vary by region.

Is composite decking worth the extra cost?

Composite decking costs 2–3× more than pressure-treated timber upfront but requires no oiling, staining or annual maintenance. Over 10–15 years, the total cost of ownership is often similar — and composite typically looks better longer.

What is the biggest cost driver in deck construction?

For large decks, the decking boards themselves (60–70% of materials). For raised decks, the substructure (posts, beams, joists) becomes dominant. Labour is typically 30–50% of total project cost for professionally built decks.

Do I need planning permission to build a deck?

Rules vary by country and region. In many jurisdictions, small ground-level decks (under 15–30 m² and under 0.5 m high) are exempt from permits. Larger decks or those attached to the house often require a permit. Always check with your local planning authority before starting.

How long does a deck last?

Pressure-treated timber: 15–25 years with annual maintenance. Hardwood (bangkirai, teak): 20–30 years. Composite decking: 25–50 years depending on quality. Regular cleaning and proper drainage are the most important factors for longevity.

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