The Timber Towers Project seeks to demonstrate the viability of a mass timber high-rise.
There are so many real timber towers on the boards or being built that one can ignore the speculative ones, but Sean McTaggart and his team at Hickok Cole Architects have designed an interesting one for Philadelphia, and tells TreeHugger that "Simply put, our mission is to change the public’s perception of what is possible with the material of wood, as an alternative to concrete & steel."
The architects mention some of the reasons that wood is good:
The Timber Towers contain 58,761 m3 of wood products, easily replenished by North American forests in less than 3 hours. 73,278 metric tons of CO2 would be sequestered in wood. Total emissions savings are the equivalent to taking 12,073 cars off the road for an entire year.
I have wondered whether one can have too much of a wood thing, and if we really should be pushing it so high. It certainly wears out all our readers' scrolling fingers. I keep wondering if the building form shouldn't be a reflection of the qualities of the material, and that mid-rises are a better typology for wood construction. But hey, we are all learning here, and the architects make a good point:
Cities have built skyscrapers using steel and concrete for over a century. They are iconic signifiers of innovation and prosperity, and yet the extraction of the building materials has been incredibly harmful to the environment. Therefore, the time has come for developers, architects, and policy makers to return to wood, the only truly renewable material that we have on earth.
They compare wood to other materials:
The extraction of materials from mines requires 5x more energy for steel and 24x more energy for concrete than it takes to harvest a ton of timber. This mining causes deforestation and severely damages habitats, and almost half of the water supply needed is wasted in the process. By comparison, 98% of a tree is utilized by a lumber mill for various purposes, with virtually no waste.
Someone in the concrete industry might point out that chopping down trees can cause deforestation and damage habitats too, which is why sustainably harvested wood, with all their restrictions on habitat destruction and requirements for replanting, is critical. There is also a danger in over-promising and over-claiming (I do not for a second believe that 98 percent of a tree is utilized; I have seen what they leave on the forest floor). And I am not totally convinced that 60-storey wooden towers are appropriate use of the material.
But we learn from every experiment and proposal, and a lot of thought went into this one from Hickok Cole.