The Paris climate agreement puts materials high on the agenda, since its about a 0-CO2 emissions target, which addresses material resources and production as well as energy: materials require lots of embodied energy energy ( see blog on buildings as Carbon bombs) , and in fact the 0-energy targets in building shifts the burden to increased impact from materials. This implies that besides a 0-energy target we also need a 0-impact materials target, or as I will explain here, a “ 0-materials” buildings target.
“0-material building” was first introduced in a article in 1999 [1] By that time it was just an interesting exploration, without very deep insight. Things have changed, and knowledge grown which makes it , 17 years later, more substantial to describe a 0-materials concept.
The impact of materials use comes down to 2 main issues: the limited availability of resources, and the effort to invest in resources to make them fit for use.
The currently popular term ‘ Circular building” requires both to be addressed. To start with the last issue: it requires effort to use materials. Or in other words: it requires labor or energy to process materials into a ready product. A first CO2 related consequence of a 0-materials approach is therefore developing “ 0-embodied energy” approach for materials production and transport , which implies that the production chain refrains from using fossil fuels , and has no CO2 emissions involved. Or in other words, a 0-energy approach for production of building elements. Which will require the building materials industry to develop a process powered by wind or solar energy, as well as find 0-energy means of transport : using sailing ships, bicycles, or maybe even electric vehicles, powered by solar or wind based electricity.
Then again, the energy devices installed to generate renewable energy should be produced with renewable energy as well. And so forth. Its a huge task, but unavoidable when we have to stay under 2 degrees of climate warming.
Its not impossible: Main shipping companies are exploring the use of sails to their vessels, electric transport is in development, and there are already industries that are partly or completely powered by renewable energy.
0-embodied energy , 0-materials building: Still around 2 billion people live in sun-dried loam brick buildings, manual labour erected… (picture from Peruvian highlands)
in-system
But the 0-embodied energy target is not the whole story. 0-materials requires also taking responsibility for the materials itself Just like depleting fossil fuels, with side effects like CO2 emissions, materials are also depleted. The point with resources is, they don’t make them any more. So a consumer or producer has to take responsibility for the materials (stock) . In other words: to take care that the original stock is not depleted but regenerated. And regeneration again requires energy . Its easy to see for wood: If you cut a tree, it takes minimal 40 years before it has regrown. In other words: there is land occupied for a certain time, and there is a maximum that you can harvest from a piece of land per year. Or: 0-depletion from materials means no more harvesting then can be reproduced over time, and reserve the land for that. Now for wood, or organic materials, this can be done with 0-impact, reserving land and have (renewable) solar energy do the job.
Its more or less the same for minerals and metals : they can be regenerated, which requires excessive generation of (renewable!) energy for that restoring process. It not further detailed here , see maxergy.org and my blogs on fossils [3][4]
In general minerals and metals require much more embodied energy and regeneration energy as does organic or biobased materials. ( see also blog on “Carbon Bomb building” ) Therefore to create a 0-materials building it will most likely be a biobased building, and this is used here as an example.
For a house from renewable resources ( timberframe, hemp, flax for insulation, bamboo for finishing materials ) we calculated what would be the actual impact from regenerating the used resources. And its about 800 m2-year you have to set aside for the reproduction of materials for 1 m2 of floor area. In other words, 800 m2 of land generates the resources in 1 year for 1 m2 of floor. [4] Or If you would spread it over 50 years, the minimal expected lifetime of a building, it would be 16 m2 permanently to compensate for 1 m2 floor. Its a lot, but this is the only way to assure that our system does not decline in potential.
So if you build a biobased house of say 100 m2’s, to function for at least 50 years, it requires a productive garden of 1600 m2 , to avoid depletion of stock, and assure that the building generates as much materials as it requires. With renewable energy this is instantly: a 0-energy house generates as much as it consumes, at least over a years budget. For a wooden house it’s the same: the house generates as much materials as it generates: the garden, only the time frame is different.
Some more sophisticated tools, like the LCA approach account for some land occupation for materials, but only for regenerating renewable resources. Calculations to compensate and restore minerals and metal stocks are never addressed. Which in fact is treating resources with two different measuring systems. ( see blog to come on closing cycles) .
But more important is that even if it would be counted, it would be just a number. While system quality would require that the land to produce resources, or renewable energy is actually reserved for that purpose. This is what is called the carrying capacity of the earth: its limited to what can be produced from that land. Just using and depleting will in the end exhaust the system.
So to summarize:
0-materials(building) = 0-embodied energy + 0-depletion (or 100% regeneration)
A 0- materials building is a building that actually re-generates its consumed resources. And If its both a 0-energy as well as a 0-materials building , it is a 0-impact building, (or even a 0-exergy building” Not creating entropy growth in the system)
[1] Dutch magazine Duurzaam Bouwen, (Sustainable Building), Special issue theme: “ 0-material” , Article: Materiaalneutraal bouwen, de eerste stappen ( Material neutral building, the first steps) . Ronald Rovers, may 1999 issue 3 p 11-13.
[2] in the MAXergy methodology and the Closed cycle calculation tool based on that, the depletion or resources, for organics as well as an-organics is incorporated, see www.maxergy.org
[3] See blog Growing Fossils: “Embodied Land” http://www.ronaldrovers.com/?p=107
[4] Designing for only energy: suboptimisation, Rovers R., De Flander K, Gommans L, Broers W. , RiBuilT, Research Institute Built environment of Tomorrow, RiBuilT paper in ARCHITECTURE AND SUSTAINABLE DEVELOPMENT, Proceedings of PLEA 2011, Louvain-la-Neuve, Belgium (July 2011) (available in my researchgate pages)
