Specialist engineers from WSP were commissioned to design the fire safety system for what is now Auckland’s tallest timber construction. Led by Auckland-based fire and life safety manager Biswadeep Ghosh, fire work on the Mission building involved design assessments, fire severity calculations, independent peer reviews and plenty of inspections.
While the two lowest levels are constructed with standard concrete and steel, the rest of the 10-storey building uses the latest in cross laminated timber – including all floors, walls and ceilings. Biswadeep says this posed a challenge in calculating the building’s fire severity rating.
“These calculations tell us how long a fire will last in a building until everything burns out. Calculations developed for steel and concrete structures can’t be used with accuracy for timber structures, so we spent two weeks calculating based on the all-timber design of the building.
“The risk of a timber building catching fire is the same as for a steel or concrete building. But timber buildings will burn for longer if the worst was to happen. That’s why getting the numbers right was so important.”