Interest in mass timber is on the rise worldwide, with architects and developers turning to timber-based systems to tackle building emissions. However, despite a surge of new buildings in the North American markets, local building codes and standards vary substantially from country to country, creating roadblocks to greater adoption.
That is according to a new guideline produced by Arup, Fire Safe Design of Mass Timber Buildings. The guideline provides an evidence-based approach to plugging gaps in local country-building regulations. It also examines scenarios where cross-laminated timber, glulam, and laminated veneer lumber can replace traditional steel-and-concrete systems.
“While the US, Canada, Australia, and some European countries have mature regulatory frameworks, many other countries don’t,” the authors of the 191-page guideline said, with the Guide looking at timber in external walls and specific fire hazards for different building components.
“The new Guide has been written to be used in any statutory jurisdiction,” according to Arup, who added, “where local codes and regulations exceed the recommendations in this Guide, they will take precedence.”
As a result, “the purpose of the Guide is to provide (fire engineers and) designers with risk-based tools to assist in the design of adequate fire safety in buildings that use a mass timber structure.”
Up to 50m tall
The Guide addresses building typologies where mass timber has the most significant potential—mid-rise office and residential buildings (up to 50 metres) and educational low-rise buildings (up to 25 metres).
According to Judith Schulz, Arup’s fire safety engineering lead: “As well as gaps in codes and regulations, there is also a lack of knowledge amongst much of the design and construction community when it comes to designing fire-safe timber buildings.”
“We hope this Guide will accelerate a move away from carbon-intensive materials and contribute to a growth in fire-safe mass timber buildings, which offer great promise for reducing CO2 in low- to medium-rise buildings,” Ms Schultz said, was part of an Arup team assisted by Dr Michael Klippel (IGNIS) and Dr Andy Buchanan (PTL Structural & Fire Consultants) in putting the guideline together.
What is the sweet spot for mass timber systems?
Last month, Wood Central reported that switching steel for CLT floors, glulam beams, and columns holds the key to lighter, faster and greener construction according to a study, Comparison of Embodied Carbon of a Mass Timber Building Structure with a Steel Equivalent, published in Buildings Journal.
At the same time, a report from PCL Construction, one of North America’s largest construction contractors, DCI Engineers, the engineers behind the world’s first post-and-plate mass timber high-rise, and design firm Weber Thompson found that mass timber hybrid high-rises are (almost) as cost-competitive as concrete-based systems and are the ideal material to build 12-18-storey mixed-use and residential towers.
That study confirms that ‘intermediate high-rise’ is the sweet spot for timber-based construction systems, adding that buildings “are often underbuilt in urban areas due to an unfortunate intersection of construction code and code requirements.”
- Click on Wood Central’s special features to learn more about the mass timber challenges to overcome and the opportunities to drive mass timber worldwide.