Viewpoint: A Call for Renewable Buildings
Updated: Nov 11, 2021
The need to move our built environment into more sustainable practices is almost universally recognized. Moving beyond operational carbon emissions as the sole carbon consideration and embracing the need to address embodied carbon – the carbon implications of the materials that make the building – is a welcome development. But we need to go further.
An underlying premise behind this sense of going further is that nature can make it with us or without us, but we cannot make it without nature.
As part of our coming to terms with climate realities, we need to focus on being more harmonious with nature. We need to think in terms of renewable buildings.
What is a renewable building? It is one where the sustainability considerations go well beyond the energy used to build and operate the building. The full derivation of the materials used in making a building and the future potential recovery and reuse of those materials needs to also be considered.
In terms of derivation, today large-scale buildings around the world overwhelmingly rely on ample use of concrete. That concrete has a matrix of cement. That cement is derived from limestone. The limestone is quite often hundreds of millions of years old. It is every bit a fossil material just as oil, gas, and coal are fossil fuels. It is inherently a non-renewable resource. Yet we seldom acknowledge this primary aspect of one of the world’s most ubiquitous construction materials.
The degree to which we have a blindside to the fossil genesis of concrete can be seen in various recent Life Cycle Analyses and Environmental Product Declarations. The energy consequences of how far a product is shipped and how that shipping takes place gets a lot of consideration as do other particulars of the manufacturing and use. But it is not uncommon to see that the fact a choice is being made between a fossil material and an organic fully renewable material get scant acknowledgement, if any.
A focus on renewable buildings, which we should do for various reasons, would help bring this aspect to the forefront of our thinking. It would also be one small step towards our needed increased harmony with nature.
The contrast between fossil building materials and non-fossil building materials is stark. Consider replenishment rates. While it can take hundreds of millions of years to replenish a source of limestone, wood being used in buildings can be fully replenished almost instantly by continued forest growth. Further, the specific replacements for the trees harvested can be replenished in a few decades. That is a night and day difference of giant proportions.
As recently as a few decades ago we would have been unable to meaningfully act at scale in recognition of this fossil construction material versus non-fossil construction material dilemma. But we can act on that recognition today. The advent of new Mass Timber technologies such as cross laminated timber and mass plywood coupled with older forms of Mass Timber such as glulam and nail laminated timber make it possible to do large-scale renewable buildings today.
These materials can last every bit as long as the fossil materials they can replace, if not longer. They are safe. They are economic. They lend themselves to eventual reuse in subsequent buildings after they have served for the life of a building. They are a true step into the realm of renewable buildings in every sense.
Mass Timber connects sustainable buildings with sustainable forests making renewable buildings possible at scale for the first time.
The time for renewable buildings is now.