When demolition becomes the sustainable option will the preservationist ignore its findings or, reductio ad absurdum, fall into the pit of Ecofascism?
As responsible preservationists we cannot afford to be magpies flitting about for the obvious shiny arguments, choosing only the low-lying fruit. If sustainability is to be the main driving argument for preservation, then it must also embrace the inevitability of demolition. In a world of continued population growth, diminishing farmland, and transportation being reliant upon fossil fuels, increasingly dense and compact cities could become more and more sustainable. Upon weighing the survival of older building stock versus the energy cost savings over a century of a building that could house hundreds of families, the sustainability argument could quickly outweigh embodied energy of extant buildings. In turn, sustaining those older traditions and technologies could be much more energy intensive, for instance some organic gardening is much more energy intensive than less glamorous conventional monocrops. As preservationists, we need to know when to let go, triage is messy, but sometimes necessary.
Nevertheless, we must be wary of a notion I once encountered in an Environmental Philosophy class, termed Ecofascism by Zimmerman and others. It would be equally ignorant to only value a building in terms of its embodied energy or lost opportunity-energy costs. Preservation must remain flexible – being aware of the toolbox of arguments that are not just effective but, yield desirable results, within the realities of practical real-world opportunities and constraints.