A relatively famous mantra of the green building movement was coined by architect Carl Elefante: “The greenest building is the one already standing.” It’s a lovely sentiment, but when you think about old structures with shoddy wiring, old windows, coal chutes, and the like, it’s a bit hard to believe. A new study shows that it’s not only true, in some circumstances it’s shocking.
Conducted by the Preservation Green Lab, the study compared “the relative environmental impacts of building reuse and renovation versus new construction over the course of a 75-year life span,” using an internationally recognized set of criteria. While the study looked at a variety of different buildings and scenarios–from elementary schools to industrial buildings converted into residential lofts–we’re going to focus on the single-family homes (as we Marmots tend to).
On average, when you renovate rather than rebuild, the environmental impact of an entire single-family home is saved…
Every 10 houses with respect to climate change.
Every 10 houses with respect to resource depletion.
Every 5 houses with respect to human health.
Every 3 houses respect to ecosystem quality.
To put this in a local perspective, by renovating the homes in The Assemblage instead of demolishing and starting over, we’re saving two entire houses worth of climate impact, two houses worth of resources, four houses worth of human health impact, and nearly seven houses worth of ecosystem quality impact–especially important this close to the Truckee.
As the study notes, “reuse-based impact reductions may seem small when considering a single building. However, the absolute carbon-related impact reductions can be substantial when these results are scaled across the building stock of a city.” This stresses the value of renovation and renewal, particularly in more densely populated, urban areas.
A new, single-family home that is 30% more efficient than the house it replaced takes an average of over 40 years repay the debt of its construction. “For those concerned with climate change and other environmental impacts, reusing an existing building and upgrading it to maximum efficiency is almost always the best option regardless of building type and climate.”