The Materials Book

39 9 Mine the City The city is a rich material resource; for example, there is more copper in buildings than is left in the earth’s crust. In Switzerland, the total copper stock in buildings is 65 kg per capita. 1 By reusing the materials already deposited in our settlements rather than extracting new raw materials, the rate of material accumulation would slow down and the amount of building materials removed and redeposited as waste would be reduced. Formally or informally, we already mine the city. In parts of the United States, copper extraction from abandoned and inhabited buildings is so lucrative that police task forces have been formed to combat metal theft. But the institutions needed to effectively mine the city are presently missing. The labor needed to sort and select materials for reuse needs an economic apparatus. Presently, although the labor of erecting new buildings is a crucial part of the economy, demolishing them is often done haphazardly and with a minimum of time and labor. 1 Peter Baccini and Alejandra Pedraza, “Die Bestimmung von Materialgehalten in Gebäuden,” in Bauwerke als Ressourcennutzer und Ressourcenspender in der langfristigen Entwicklung urbaner Systeme: Ein Beitrag zur Exploration urbaner Lagerstätten (Zurich: vdf, 2006), 103–32.