Nestled among spruce forests in an Alpine valley in southern Austria, a workshop was the first some two decades ago, to begin manufacturing a green new material that’s now super-sizing wooden buildings and speeding the adoption of a solution to mitigate climate change.
“We can build very quickly and cleanly with it and that’s the key,” said Marco Huter, a 57-year-old executive surrounded by giant slabs of cross-laminated timber, called CLT, at his KLH Massivholz GmbH factory.
Huter had to double capacity in the midst of coronavirus lockdowns to satisfy booming global demand for the mass timber he produces. Developers are adopting the material to reduce their carbon footprints while also cutting the cost and time needed to construct high rises, he said
CLT uses a high-tech manufacturing process that turns ordinary wooden planks, often made from the nearby Spruce trees, into structures that can bear thousands of tons of weight. Architects from Australia to Scandinavia and the U.S. have been buying from Huter as they leapfrog each other in a race to construct the world’s tallest wooden skyscraper. Vienna made an entire new city quarter out of CLT. Designers in Japan have planned a 350-meter (1,148-foot) tower.
Huter pointed to a project at 55 Southbank Boulevard in Melbourne, Australia which used his timber to add 10 stories onto a six-floor building, more than doubling its height and living space in less than a year. Because wood weighs just 30% of concrete, CLT is being used to expand scarce space in cities by building higher. Construction time is quicker than pouring concrete on site, resulting in lower labor and equipment costs.
Builders emit more than a fifth of the greenhouse-gas emissions spewed into the Earth’s atmosphere every year and convincing them to adopt greener materials -- which include hemp and even straw -- will be key to keeping global temperature increases well below the 2-degrees-Celsius (3.6 degrees Fahrenheit) mark mandated by the Paris climate accord. But it’s not just CLT’s potential to rapidly put the brakes on emissions that’s behind demand.
Using timber “significantly reduced” construction time, according to Bates Smart, the architectural firm that designed 55 Southbank. Wood in the structure sequestered some 4,200 tons of carbon dioxide, equal to the annual emissions of 130 homes.
“While still nascent on the investment landscape, it offers potentially high returns as it scales up and consumer demand drives it deeper into the market,” said Matthew Sebonia, director of Global Climate Capital who’s been tracking the industry’s emergence for two years.
All of this progress in using wood as an alternative began three decades ago by an Austrian doctoral student who tinkered with wooden structures at university, long before the fight against global warming had focused the minds of manufacturers.
Gerhard Schickhofer said he never imagined the super-strength material he engineered would one day be be hailed as a potential answer to the construction industry’s concrete problem. The 59-year-old is so convinced of the material’s effectiveness that he eschewed patenting his knowledge in favor of trying to widely disseminate the techniques he developed.
“It wasn’t about climate change or disrupting industry when we started, though that now seems to be where we’re headed,“ said Schickhofer, 59, in an interview at his laboratory in Graz, Austria. “We have an important opportunity here to build with a new kind of material.”
More than 65 CLT factories have been built worldwide in a little over a decade with 15 new units on the way, according to Schickhofer, who receives a steady flow of global investors visiting his workshop, including from Softbank-backed Katerra Corp.
“I’ve never seen anything in my 40-year career that has generated this much interest,” said Katerra’s Craig Curtis, an architect and one of the design chiefs at the Menlo Park, California company, which imported Schickhofer’s technology to build North America’s biggest CLT plant last year.
European companies including Stora Enso Oyj and Binderholz GmbH still dominate the market but new production centers are going up in timber regions from Canada to Russia. Annual CLT sales could triple from more about $1 billion over the next few years as governments induce greener construction, according to Schickhofer.
CLT is becoming “the new concrete” at construction sites across central Europe, according to Manfred Senff, who runs Purelivin GmbH, an Austrian builder that’s using the material for Lego-like housing modules that can be quickly installed as social housing in cities.
It costs between 2,000 and 2,500 euros ($2,371 and $2,964) a square meter of CLT used on European construction sites. That might be more than the cost of pouring concrete, but the material’s proponents say that CLT is actually cheaper when factoring in the time scale of construction. Onsite assembly is quicker than traditional building methods, thereby reducing expenses like crane rentals, labor and waste.
At KLH, where Schickhofer conducted his experiments, the CLT production process is highly automated, with just 200 workers producing more than 3,000 square meters of material a day.
The factory floors are sparkling clean and run for hundreds of meters. Humidity and temperature are carefully controlled with jets of mist occasionally released from the ceiling. Each plank runs a processing gauntlet that sees its ends carefully jointed and then sealed to the next with adhesive.
They’re then cross-laid and fed into a pressing chamber about the size of the penalty area on a soccer pitch. A single worker behind safety glass pulls levers that apply layers of adhesive and triggers a press that applies tons of pressure on each section of the timber.
After the CLT, which is now about 20 inches thick, leaves the press workers dangling in mid-air from gantries inspect the product inside a vast hall where highly-trained carpenters make cuts for windows, doors or building shape.
X-ray machines scan wood entering the climate-controlled facility for defects. Every CLT unit produced is given a unique digital number that allows builders all over the world to trace each piece back to its source.
For Austrian timber merchants, who cover about half the world’s CLT demand, the material is a bridge linking the digital age to three centuries of forest management begun by Hapsburg Empress Maria Theresia. She saw Austria’s forests as a national-security resource and mandated strict sustainability laws. Today, woodland growth every 24 hours in the country of 9 million people generates mass equivalent to the material needed for 2,000 new homes, according to the country’s timber association.
Bringing that level of data-driven land management to some of North America’s neglected woodlands, which face climate-induced threats like fires and invasive pests, could prove to be CLT’s biggest impact, according to Katerra’s Curtis, who convinced former Tesla Inc. executive Michael Marks to get behind building his factory in Washington state. CLT production relies on cultivated tracts and doesn’t require old-growth trees to be felled.
“CLT allows us to design the future of wood and shows how to keep the forests alive,” said Richard Stralz, the chief executive officer of Austria’s Mayr Melnhof Holz Holding AG, which recently finished a new 130 million-euro massive timber factory.
While Spruce might be the wood of choice in Europe, Douglas fir is favored in the U.S. and Schickhofer’s team of CLT researchers is already experimenting with new CLT materials made out of pest-resistant hard woods, as well as fast-growing species like eucalyptus.
“We need to be much faster in using this material if it is to be part of a climate solution,” he said. “The bottleneck is knowledge.”
©2020 Bloomberg L.P.
