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Timber Towers Are On the Rise in France (citylab.com)

Posted by msmash on from the moving-forward dept.

A reader shares a report: Spurred by concerns over climate change and the negative impacts of concrete manufacturing, architects and developers in France are increasingly turning to wood for their office towers and apartment complexes. Concrete was praised through much of the 20th century for its flexibility, functionality, and relative affordability. In France, the material ushered in an era of bold modernist architecture including housing by Auguste Perret and Le Corbusier. Today, however, wood is lauded for its smaller environmental footprint and the speed with which buildings can be assembled. "Wood had largely disappeared and was seen as a quaint material," says Steven Ware, a partner at the architecture firm Art & Build, whose latest wooden office building opened in Paris's 13th arrondissement earlier this summer. "[But] the energy it takes to put a concrete building up, to run it, and then dismantle it when it becomes obsolete was too much. Using mass timber in office buildings seemed like something we had to do." The production of cement, one of the main ingredients in concrete, generates an estimated 5 percent of the world's carbon emissions. Trees, in contrast, capture CO2, helping offset emissions produced by a typical building process. And then there's the string of other construction advantages that make wood economically appealing. It's lighter, which means digging smaller foundations in the ground. Crane costs come down, as they're no longer hauling blocks of cement hundreds of feet in the air. Driving a nail into a slab of wood requires a lot less energy than driving one into concrete. Months can be knocked off the construction timeline.

4 of 202 comments (clear)

  1. Fire anyone? by Anonymous Coward · · Score: 4, Insightful

    Sounds like a good way to have a towering inferno. The stuff we put inside large buildings burns quite readily. But the fire generally stops in a single room. But if you suddenly make everything out of wood, what's to stop the fire from spreading everywhere?

    1. Re:Fire anyone? by blindseer · · Score: 4, Insightful

      But if you suddenly make everything out of wood, what's to stop the fire from spreading everywhere?

      First, as stated in the article the wood panels are engineered lumber that is very thick. There is very little surface area to the wood used, compared to like what people use in a fireplace or backyard bonfire, so the wood will not burn quickly if the char layer that develops doesn't stop the fire completely.

      Second, most every building code I've seen will require a fire resistant layer around structural components. In most houses this is done with sheets of drywall over the wood studs in the wall. Typically 1/2 inch on walls and thicker on ceilings.

      My brother was an architect and I remember the topic of the fire rating of doors coming up. Wood doors are actually quite durable in a fire, and those certified as a fire rated door will have a little metal badge on it giving it's fire rating. The goal of a fire rating is not necessarily the survival of the building but the survival of the occupants. So long as the building holds up long enough for people to get out in a fire then it's considered safe for people. A quick Google search tells me a wood fire door will be fire rated for 20 minutes, I assume the thick wood floors that they are using will hold up for much longer.

      Remember, these fire ratings are tests under direct exposure to a fire before the door is not considered a barrier to the spread of fire. It's not like the whole building will come down 20 minutes after a fire starts. If a building is large enough, or contains flammable materials, then it's likely to have sprinklers.

      In other words, I think they have this figured out.

      --
      I am armed because I am free. I am free because I am armed.
  2. Driving nails? by Anonymous Coward · · Score: 1, Insightful

    Are they really comparing the energy cost of driving a nail?

    Wood has a place but IMO if you want a durable structure use reinforced concrete. Maybe this wave of construction is only expected to stand for 30yrs?

  3. Re: Trading one problem for another by WarJolt · · Score: 2, Insightful

    Also there is a fair amount of carbon sequestered in the building itself. That's assuming the building doesn't burn, which is why I won't get into a tall wooden structure.