Where mass timber wins.
1. Mid-rise residential and office
For 4–8 storey buildings with a clear repeating grid, CLT panels and glulam columns/beams typically beat steel-and-concrete on programme by 15–25%. The lighter superstructure also reduces foundation cost — sometimes enough to fund the (slightly more expensive) frame.
2. Long clear spans with exposed structure
Sports halls, community pavilions, education buildings — anywhere the structure is part of the architectural intent. Exposed glulam beats exposed steel on acoustics, on warmth, and frequently on cost-of-finishing.
3. Projects with deep carbon scrutiny
Government and institutional clients in both NZ and AU increasingly require embodied carbon assessment. Mass timber typically delivers 30–60% embodied carbon savings over equivalent steel-and-concrete, which can be the deciding factor on tenders with explicit carbon criteria.
4. Constrained urban sites
CLT panels arrive pre-cut, lift fast, and produce dramatically less site noise and dust than conventional concrete. For tight Sydney, Auckland or Wellington CBD sites, neighbour impact savings can be material.
Where steel still beats it.
1. Single-storey industrial
For a portal-frame shed, steel is still 25–40% cheaper than mass timber and faster to erect. Mass timber portals exist but rarely make commercial sense below 15m clear span.
2. Highly serviced ceilings
If your tenant requires deep ductwork, sprinkler density, or extensive cable trays — anything that wants to live in or below the soffit — exposed CLT loses its visual win, and you might as well use a faster steel deck with a suspended ceiling.
3. Severe fire-rated separation
Mass timber can absolutely achieve high fire ratings (the NCC and NZBC now recognise this), but the design effort and cost is higher. For party walls, lift cores and stair shafts, concrete is still often easier.
4. Tight budgets without programme value
If your build doesn't benefit financially from going up faster — owner-occupied, no pre-let, no construction-finance pressure — the cost premium on mass timber over equivalent steel-and-concrete (typically 5–15%) can be hard to justify on first principles.
The cost picture.
For a benchmark 6-storey, 4,000 m² residential apartment building in Sydney or Auckland, 2026 prices:
- Concrete frame, post-tensioned slabs: ~AUD/NZD $3,400–$3,800 / m² superstructure cost.
- Steel frame, composite slabs: ~$3,500–$3,900 / m².
- CLT + glulam hybrid: ~$3,700–$4,200 / m² superstructure cost, BUT 15–20% programme saving and 30–40% foundation saving.
Net cost difference is often within 5% — programme and embodied-carbon outcomes are the deciding factors.
"For owner-developers running a 24-month programme on borrowed money, the financing saving from a 4-month-faster mass timber build can be larger than the superstructure premium."
Procurement realities.
1. Supply
Australia's domestic CLT supply (XLam, Hyne) has improved but is still capacity-limited on big projects. Many projects import from Austria, Germany or Japan, which means 14–18 week lead times and exposure to FX and shipping volatility. NZ has Red Stag's CLT plant in Rotorua, but capacity is finite.
2. Trades
The pool of contractors who've installed mass timber more than twice is still small in both countries. Expect 10–15% tender premium from contractors pricing in their learning curve.
3. Insurance
Project insurance for mass timber has tightened over the last five years — wet-trades insurance is easier to source than mass-timber-during-construction insurance. Make sure your insurer is briefed before procurement, not after.
How we'd advise.
Our default starting position on a mid-rise residential or office brief:
- Run a quick mass-timber vs concrete comparison at concept stage. Five working days, side-by-side.
- If programme saving is worth more than $200,000 to the project, lean mass timber.
- If the brief has explicit embodied-carbon criteria, lean mass timber.
- If neither applies and the cost delta is more than 4%, lean concrete or steel.
Worth noting
The NCC 2022 amendments in Australia explicitly recognise mass timber to 25m effective height for Class 2, 3 and 5 buildings — the previous practical ceiling of 8 storeys is no longer a hard limit. NZ's MBIE Acceptable Solution C/AS2 has equivalent recognition. Mass timber is now a mainstream tool — but treat it as one option, not a default.