Decks are one of the most popular outdoor projects in NZ — but prices have moved a lot, materials have changed, and many quotes come back wildly different for what looks like the same job. Here's how to make sense of it.
The headline numbers (2026, Waikato)
- Treated pine deck (30sqm): $12K–$18K
- Premium timber deck — Kwila, Garapa, Vitex (30sqm): $18K–$30K
- Composite deck (30sqm): $25K–$40K
- Capped-composite premium deck (30sqm): $35K–$50K
- Deck with pergola/roof: add $10K–$30K depending on scale
These are turnkey numbers — including substructure, materials, labour, fixings, balustrades where required, and finishing.
Timber vs composite — which should you pick?
Timber decks
Timber is the traditional choice. Looks beautiful, can be refinished, and costs less upfront. The downside: it needs annual maintenance — oiling or staining — and even with care, hardwoods like Kwila go grey within 2–3 years if you don't keep up the oil.
Treated pine is the budget option, fine for utility decks but prone to warping and splintering with age. Premium hardwoods (Kwila, Garapa, Vitex) look better and last longer but cost more.
Composite decks
Composite boards (timber/plastic blend) cost 50–80% more than timber upfront but need no oiling, no staining, no annual maintenance. They don't splinter, don't warp, and don't go grey.
The downside: they get hot in direct sun (some products noticeably so), and they look like composite — which some people love and some people don't. Capped-composite is the premium tier, with much better colour stability and heat resistance.
Honest recommendation
If you'll oil your deck every year: timber. If you won't: composite. The total cost of ownership flips at around year 12 — composite is cheaper overall once you factor in maintenance.
Do you need a consent for a deck?
Most ground-level decks under 1.5m above ground don't require a building consent. Above that height, attached to a habitable building, or with a roof — and you usually need one. See our building consent guide for the rules.
What drives the price variation
Substructure complexity
A flat ground-level deck on a simple piled substructure is the cheapest. Sloped sections, elevated decks, decks integrated with retaining, or decks built over difficult ground (clay, watertable) all add cost — sometimes significantly.
Material choice
See above. Treated pine is roughly half the cost of premium hardwood; composite is roughly double.
Balustrades and finishing
Any deck above 1m requires balustrades (a railing). Glass balustrades are premium ($1,500–$2,500/lineal metre); timber balustrades are cheaper. Steps, screens, and built-in seating add cost on top.
Site access
Hard-to-reach sites (no driveway access, requiring wheelbarrows or crane lifts) add labour cost. Most builders factor this in to the quote.
The honest summary
Pick the deck size that actually suits how you'll use it (most people overbuild). Pick the material based on whether you'll maintain it. Confirm consent requirements before you commit. And get a fixed quote — the price variation between “rough estimate” and “fixed contract” can be 30%+.
Finer Builds builds timber and composite decks across the Waikato. Book Your Free Consultation for an honest quote on your specific project.