From a Low-Rise Material to a Genuine High-Rise Contender
Timber construction was, until relatively recently, broadly assumed to be limited to low-rise buildings — a few storeys at most, constrained by fire concerns and the structural limitations of ordinary sawn lumber. The emergence of engineered mass timber products (cross-laminated timber panels, glulam members like those covered elsewhere in this series, and related engineered wood products) has truly changed that picture, with completed buildings now reaching 18, 25, and in a handful of cases over 85 metres in height, built predominantly from engineered timber structural systems.
Why Mass Timber Performs Better in Fire Than Intuition Suggests
It seems counterintuitive that a combustible material could be an acceptable choice for tall building structure, but large mass timber sections behave very differently in fire than ordinary thin lumber does — a thick glulam or cross-laminated timber member chars on its exposed surface at a slow, predictable rate, and that char layer itself acts as an insulating barrier protecting the uncharred timber core underneath, allowing the member to retain significant structural capacity for a meaningfully long, calculable fire duration, not unlike how concrete cover protects reinforcement discussed elsewhere in this series, just through a different mechanism.
If you want to see this logic applied to a real section, the Structyze Glulam Beam module runs the same checks live in your browser, free — useful for sanity-checking your own numbers in minutes rather than rebuilding a spreadsheet.
What Actually Limits How Tall a Mass Timber Building Can Go Today
The practical ceiling on height today isn't primarily a strength limitation (engineered timber's strength-to-weight ratio is really competitive) — it's more often driven by lateral stiffness (timber's lower modulus of elasticity compared to steel or concrete, discussed in the context of other timber design checks elsewhere in this series, makes wind-induced sway control harder as height increases), fire code approval processes that vary significantly by jurisdiction and are still evolving for very tall timber specifically, and connection design at the scale needed for very tall structures, an area still actively developing compared to the decades of accumulated steel and concrete high-rise connection experience.
Quick FAQ
Do very tall timber buildings use timber for the entire structural system?
Not always — many tall timber projects use a hybrid approach, combining a mass timber superstructure with a concrete or steel core (for lateral stability and additional fire compartmentation) rather than relying on timber for every structural function, which is currently a common and pragmatic way to extend achievable height.
Is mass timber construction faster than concrete or steel for a comparable building?
Often significantly, yes — prefabricated mass timber panels and members are manufactured off-site to precise tolerances and erected on site similar to a large-scale assembly process, frequently achieving faster overall construction schedules than cast-in-place concrete, a genuine practical advantage beyond the structural and sustainability considerations.
Final Thoughts
Mass timber's rise into genuine high-rise territory is one of the clearest examples of a 'future of structural engineering' trend that's already substantially arrived — not a speculative technology, but a maturing structural system working through the remaining real engineering and regulatory challenges (lateral stiffness, connections, fire code harmonization) on the way to even taller buildings.