Mass timber (cross-laminated timber floors and walls on glulam columns and beams) is moving from demonstration projects to mainstream commercial buildings. For an owner, choosing it is less a design preference than a set of early decisions about structure, fire, procurement and program that shape the whole project.
Why owners choose it
- Carbon: the embodied carbon in the structure is far lower than in concrete and steel, which increasingly matters to tenants, lenders and planning authorities.
- Weight: a lighter structure can mean smaller foundations and simpler basements.
- Speed and precision: prefabricated elements arrive cut to size and go up quickly, with fewer trades on site.
- The space itself: exposed timber is a leasing advantage tenants notice.
What changes
- Decisions come earlier. The structural grid, the connections and the fire strategy have to be resolved in design, not at tender.
- Fire engineering. Beyond the deemed-to-satisfy limits for fire-protected timber in the National Construction Code, a performance solution is needed. Engage the fire engineer early.
- Acoustics. Timber floors need careful separation between tenancies, and between hotel rooms.
- Procurement. There are few suppliers. Engage them in design and price the structure with the people who will make and install it, not by allowance.
- Moisture and sequencing. The structure has to be protected during construction.
- Finance and insurance. Some lenders and insurers need more information than they would for concrete, so start those conversations early.
What it does for the planning case
A mass timber structure, backed by firm sustainability commitments, gives a planning authority concrete reasons to support a project. At Stephenson Street in Cremorne, the 15-storey mass timber office building's sustainability commitments were part of the case for its height.
Two projects
- 57–71 Stephenson Street, Cremorne: 15 storeys of cross-laminated timber floors on glulam columns, with low-carbon concrete kept to the basement and ground floor. Set to be the tallest mass timber office building in Australia.
- Hotel Optimismo, Adelaide: 32 levels of hotel, offices, wellness, restaurant and retail in one mass timber structure from the ground to the roof. Set to be the tallest fully mass timber building in Australia, with the timber structure priced and resolved early for Finding Infinity.