Steel and concrete may still be the mainstays of many of today’s office developments but fresh thinking around sustainable construction could see a new breed of building come to the fore.
Around the world, two trends are coming into play; engineered timber buildings and modular construction methods, such as those for the high-rise hotels springing up across the U.S.
Combining these two trends in future office developments could kickstart a new era of cost-effective, sustainable buildings that help cities achieve their zero-carbon goals.
Take the proposed 18-storey residential Toronto Tree Tower, where a cross-laminated timber structure, supported internally by steel and concrete elements, would be embellished with plants to bring more nature back into the centre of the city.
“The design and build of modular timber offices is at an early stage but developers are beginning to see the economic, environmental and social benefits when compared with traditional building materials,” says Michael Davis, head of JLL Unlimited.
Cost-effective - for budgets and the planet
Like with other modular constructions, modular timber office components would be designed off-site to meet the required specifications and delivered just before they need to be assembled on site.
“If you can accelerate construction, there are considerable costs to be saved - both financially and environmentally,” says Davis. “It’s about less materials being brought to the construction site, while rebalancing the off-site, on-site split.”
Use of modular timber components can reduce site deliveries by 80 percent, mitigating pollution while reducing labour requirements on site and improving safety. Timber is equally less harmful to the environment than concrete.
While cement is responsible for an estimated 8 percent of the world’s carbon emissions, when used effectively, timber can absorb CO2 for around 30 years. Furthermore, it can improve a building’s energy performance.
The Technique building, in London’s Clerkenwell district, incorporates timber as part of its extension. The 73,000 square foot former gin warehouse will have two new floors made of glued laminate timber (Glulam) and cross-laminated timber. It is estimated that when complete, the extension will emit 48 percent less CO2 than its steel equivalent, and means the entire building emits 23 percent less overall.
“Such noteworthy cuts in emissions come at a time of increased emphasis on all sectors to cut their carbon footprint,” says Davis. “There’s no reason why timber construction cannot be a force for good across the office sector as countries aim to cut their emissions to zero.”
For now, at least, taller buildings, generally above 9 storeys, can’t be built with timber alone. Instead, they require a hybrid approach with concrete cores which allow timber to be used for the upper floors without impacting the stability of the overall building.
However, timber could equally be used for the higher levels of building extensions, such as London’s Technique building. Especially in already dense urban areas, landlords could find engineered timber a less disruptive and more economical choice than other materials to add on extra space.
“Adoption of timber is naturally more likely where there is pressing need to address low supply due to densification, or the fact that land is at a premium in many major cities,” says Davis.
On a design level, timber can also combine with traditional materials and “wears in rather than wears out over time”, says Davis. Take the head office of UK furniture manufacturer Vitsoe in Leamington Spa which combines concrete flooring with timber and was designed on the basis of 17 adaptable modular bays.
“There’s definitely scope to combine with established building methods,” he says. “Modular timber can work as columns, walling or flooring and offer the end user more flexibility.”
Further into the building’s lifespan, there’s also the potential to deconstruct and re-use timber in a way that can’t be done with concrete.
“Modular timber can be easily disassembled or repurposed – bringing forward opportunities for a more supple approach to redevelopment,” says Davis, pointing to the fully demountable timber offices of Triodos Bank in the Netherlands, built with 165, 312 screws.
And while developers are starting to eye its potential, it will take some high-profile, high-rise modular timber projects to be completed – not to mention increased regulatory pressure to clean up construction - for the concept to gain ground.
“Timber is an increasingly viable alternative to concrete when developing new offices or extending existing buildings,” says Davis. “It just requires bold thinking from developers to take this new idea on board.”