More Developers are Choosing Wood Over Other Construction Materials

Contemporary apartment building made of wood at Hamburg

A new report in The New York Times outlines how climate change is spurring developers to increasingly choose wood over common construction materials like steel and cement, especially with the rise of cross-laminated timber (CLT).

Laminated wood panels are ultra-strong, and can be used as a primary material for tall wooden buildings. The market for “mass timber” buildings is rapidly growing in the United States and around the world.

“Developers are turning to wood for its versatility and sustainability. And prominent companies like Google, Microsoft and Walmart have expressed support for a renewable resource some experts believe could challenge steel and cement as favored materials for construction.”

“‘We are making huge headway in the U.S. now,’ said Michael Green, a leading mass timber architect for Katerra who is based in Vancouver, Canada, and designed the Catalyst Building and several more in North America.”

“Wood has several advantages over other building materials, including the ability to help curb climate disruption, that are driving the interest, he said. Steel and cement generate significant shares of greenhouse gases during every phase of their production. By contrast, wood stores carbon, offsetting the emission of greenhouse gases. ‘The environmental aspects alone are attractive,’ Mr. Green said. ‘Cross-laminated timber panels are faster to assemble. There’s much less construction site waste.’”

Using wood instead of heavier steel and cement can also save labor costs and come with other benefits.

“Another significant promoter is Hines, a global real estate investment, development and management firm based in Houston. Four years ago, Hines opened T3, a seven-story, 221,000-square-foot, cross-laminated timber office building in Minneapolis also designed by Mr. Green. The wood structure cost $60 million, 5 to 10 percent more than one built with concrete and steel. But the ease and speed of lifting and fitting manufactured pieces into place saves money on labor, said Steve Luthman, a senior managing director at Hines.”

“In addition to the labor savings, tenants are attracted to wood surfaces in work spaces. Hines sold the building in 2018 for $392 a square foot, a record for a Minneapolis office building.”

Eastern White Pine has been found to be structurally sound for use in cross-laminated timber by the University of Massachusetts at Amherst, opening the door for this sustainable species to join others currently grown, harvested and processed for use in large mass timber construction projects.

Image via IWBC

France Will Require All New Buildings to Be Made From 50% Wood

Paris Olympic Village rendering by Dominique Perrault

Here’s an interesting update on the international trend towards more wooden architecture. The French government is implementing a new sustainability law requiring all new public buildings to include at least 50 percent timber in their construction.

Set to be implemented by 2022, the law will affect all buildings financed by the French state, according to Agence France-Presse. The decision aligns with the country’s Sustainable City Plan, launched in 2009, which aims for France to be carbon-neutral by 2050.

“I impose on all the public establishments which depend on me and which make the development or the policy of land to build buildings with materials which are at least 50 per cent of wood or bio-based materials,”  the country’s minister for cities and housing Julien Denormandie told the French news agency.

Taking Inspiration from the Olympics

Denormandie made the announcement following his seminar at the Living in the city of tomorrow event at UNESCO on February 5. He explained that building the 2024 Paris Olympics complex entirely from timber provided inspiration. “We made this commitment for the Olympic Games. There is no reason why what is possible for the Olympic Games should not be possible for the usual constructions.”

Hyperion building in France
Hyperion building in France

Dominique Perrault’s master plan for the Olympic Village will be located in the lower-income neighborhood of Saint Denis and feature a series of mid-rise passive or energy-plus developments made of wood or other sustainable materials, which could include hemp or straw. France’s first residential tower made from mass timber, Hyperion, is also expected to inspire new wooden buildings when it opens next year.

A Note on Fire Safety

When we talk about new large-scale timber projects, the most common question asked is, “but what about fire risk?” These kinds of wooden buildings are made from engineered wood like glulam, cross-laminated timber (CLT) and laminated veneer lumber (LVL). They’re light, strong, more sustainable than materials like concrete and steel, and yes, they’re designed to meet or exceed fire codes and standards. The reason we’re seeing more large-scale wooden architecture is that tests have proven the safety of these materials, leading to changes in building code around the world.

In fact, you can take it straight from firefighters. Here’s a brief snippet of an extensive piece on the fire safety of tall timber buildings.

“Most fires that occur in structures are room-and-contents fires, with the first material ignited being the contents of the room. As long as combustible building contents exist (e.g., furniture, computers, personal belongings, files), there will never be a truly non-combustible building. The building materials utilized in construction will never prevent a room-and-contents fire, but they must be able to resist the fire for an acceptable period of time. The automatic sprinkler system keeps the fire in check, preventing flashover, and the fire alarm notifies the occupants. Eventually, any building material will fail if the fire burns long enough. Steel will lose strength and fail, concrete will spall and fail, and wood will char and fail. That is why fire testing is essential for all building materials.”

“In December 2015, the ICC board of directors established an ad hoc committee of designers, code officials and members of the fire service, including firefighters, fire chiefs and fire protection engineers. Their task was “to research and design fire testing of mass timber and to draft code changes that ensure that tall mass timber buildings have redundant and rigorous fire safety systems that will protect the public that occupy tall mass timber buildings and the first responders that respond to them in emergencies.”

“The committee’s proposals identified a rigorous set of fire protection requirements that ensured that during reasonable fire events, no structural collapse will occur despite a complete burn-out of the room and contents. This performance is expected to occur even in the rare event of a sprinkler system failure. After two years of study, discussion, testing and analysis, the committee concluded that the proposals recommended would provide life safety protections to the public and first responders that are equal to or greater than tall buildings that are made of steel or concrete.”

For even more information, check out this update on the fire safety of timber construction at the Building Products Digest.

Eco-Luxury Hotel in Paris Will Have a Wooden Facade

kengo kuma wood hotel 1

With a nearly all-wood design that’s being hailed as a refreshing change from typical steel and glass, Kengo Kuma’s stunning ‘1hotel Paris’ project will bring eco-luxury lodgings to the Rive Gauche neighborhood in Paris. The Japanese-born, Paris-based architect is well known for his signature wooden designs, which often feature stacked and slotted wood pieces that fit together in puzzle-like arrangements.

kengo kuma wood hotel 2 kengo kuma wood hotel 3

The facade of the hotel features wooden panels overlapped and set at irregular, asymmetrical angles to ‘blur’ the building’s shape and mimic the pattern of branches on a tree. Lush greenery protrudes from between these panels, helping to purify the air in the neighborhood.

kengo kuma wood hotel 5

“In the dense urban context of the Avenue de France, we felt the need to create a green lung for the city,” says the architecture firm. “Nature finds a place at the core of the scheme, translated in the intimate public garden where all senses are awoken.”

kengo kuma wood hotel 4

“In the context of repetitive volumes along the avenue, our design strategy was to create a sculptural shape as formed by natural erosion that will let the sky come down to the street. The work on the volume is defined by the modularity of the wooden structure. As particles, dispersed facade panels together with the volumetric decomposition come to blur the shape of the building. The warm materiality of the wood is combined with the soften reflection and aerial touch of the metal panels. The building will come alive with the light.”

The 1Hotel will be home to 140 rooms, including 23 suites, a 179-bed hostel, a 120-seat cabaret and a 1,000-square-foot sports hall as well as bars, restaurants and offices. There’s also a central garden surrounded by staggered walls, a series of multi-level garden terraces and a swimming pool.