Why We Should Be Building Out of Sunshine

Materials palette
Materials made of sunshine.

Lloyd Alter

That is what building out of wood and natural materials essentially is: Carbon, water and sunlight.

Bruce King has written a new book, coming out in the fall, called The New Carbon Architecture, with the subhead Building Out of Sky. By this he means building out of materials that come from the sky-- carbon from the CO2 in the air, sunlight and water -- which, through the process of photosynthesis, are turned into plants that we can turn into building materials.

We can structure any architectural style with wood, we can insulate with straw and mushrooms... All of these emerging technologies and more arrive in tandem with the growing understanding that the so-called embodied carbon of building materials matters a great deal more than anyone thought in the fight to halt and reverse climate change. The built environment can switch from being a problem to a solution.

Treehugger has promoted wood construction because of the way it sequesters carbon, but Bruce King takes it much further. Where I have been excited about buildings that actually measure their embodied energy and carbon and pay off the debt over the life of the building, we’re talking here about starting at zero carbon or net positive on day one. I am really looking forward to reading this book.

Picking up on the story in Green Energy Times, Ace McArleton notes that we don’t have time for payback calculations or offsets anymore. But we have choices and alternatives:

It is absolutely possible to design, construct, repair, and maintain equally-high performing, energy efficient and durable buildings with not only low- or zero-embodied carbon materials, but with materials, that sequester – or store – carbon, giving that building a net-positive carbon footprint. Our buildings then become tools in the project of global drawdown of CO2; they become reservoirs for CO2 and help to reduce and reverse climate change effects
carbon in buildings

The Carbon Elephant in the Room Chris Magwood via Green Energy Times

Ace McArleton (I love that name) explains how the natural materials we can use now, from straw to hempcrete to timber to cellulose, are as good or better than synthetics, and how they now fit into green building practice:

Many of these materials have ASTM ratings, tested R-values, vapor-permeance values, structural and fire testing, strategies for air-tight installation and designs, and professionals to manufacture and install them. Plant-based building materials, the ancient choice for human habitation, have been brought up to stringent green building standards and have surpassed petrochemical-based materials such as foam and plastics on multiple fronts: excellent thermal performance and air-tight assemblies; low or no toxicity in production, use, and end of life; vapor permeability and moisture storage capacity (where appropriate); and excellent durability, fire resistance, air-tightness, and beauty.

Many will argue that this isn’t really true, that straw doesn’t have the R value of foam, that they are not as fire resistant, that they are not as durable. It is certainly not as cheap and fast as conventional material choices. But there is a bigger picture that we have to keep in mind:

Most importantly to the evolving net positive building landscape, they offer terrific carbon sequestration value, “fixing” carbon into the building for generations.

It also becomes evident that we have to change the way we plan and design our cities so that they take advantage of these materials, by learning from the cities that were built that way. Because as important as it is how we build, what we build has even more impact. Back to Bruce King, from his book's introduction:

Bruce kind on cities

© Bruce King from the Introduction

Had I been the author of Bruce King’s book, I might have titled it Building out of Sunshine, because that is really the source of energy that is driving this process, and should eventually drive everything from our lights and devices to our transportation.

This is how it all rolls into a bigger picture -- how we have to build zero carbon buildings and get to them with zero carbon transportation, which really means designing our cities so that we can get around by walking, followed by bikes, followed by public transport. It’s all encompassing, about trying to live a carbon-positive lifestyle. We have to do this, and our buildings are probably the easiest place to start.