Karelia Martinez Carbonell
Martinez Carbonell is the president of the Historic Preservation Association of Coral Gables
April marks Earth Month. Mother Nature is watching. Be nice.
Stewardship of our planet starts with preserving what already exists. This brings one to the ever growing issue of environmental sustainability and the need for cities, including Coral Gables, to focus on integrating the reduction of embodied carbon in its sustainability objectives if the goal of reaching carbon neutrality by 2050 is to be attainable. Why is this issue not being factored in when new projects are proposed?
A must read on the subject is “Carbon Calculus” by Katherine Logan. The article highlights that worldwide, between now and 2050, embodied carbon [the greenhouse gases generated during the extraction, manufacture, and transportation of building materials, and during construction and disposal] is expected to account for over half of total greenhouse gases from all new construction according to a recent report from the World Green Building Council. A decade is about the amount of time remaining for reining in emissions.
This information is critical for developers and design teams. It adds a layer of accountability and elevates the need to lower embodied carbon, as well as operating emissions, for a total carbon takedown. And there’s one surefire way to do it. “Adaptive reuse is the best way to reduce embodied carbon—period,” says Andrew Rastetter, an architecturally trained structural engineer who is cited in the article. Although reducing plastic consumption is important, concrete and steel are the major repositories of embodied carbon in the built environment (cement manufacturing alone accounts for 8 percent of global CO emissions). “I want architects to understand how critically important this is. If there’s existing building infrastructure on-site, we need to consider whether there’s something we can do with it,” says Rastetter.
Coral Gables has several proposed projects that can benefit from a carbon reset. One public project, the proposed 10-story mobility hub, could be reconsidered solely on the need to reduce embodied carbon. Demolishing the existing Garage 1 structure [releasing decades of embodied carbon] only to build a new parking garage sounds environmentally antiquated. The Logan article mentions that “Cities worldwide are cutting back on parking requirements” yet our city continues its move to increase its parking footprint. The article also highlights the architectural firm Gensler [coincidentally architects of the proposed mobility hub] which “adapted a failing 1960s building reducing embodied carbon by 68% of what new construction would be…”
Concrete and steel are the major repositories of embodied carbon in the built environment.In climate speak, it means hundreds of years to offset carbon debt.
At the recent commission meeting, when discussing the mobility hub project, the city manager used the term “adaptive reuse” to describe the new hub. When inquired, it was explained that his use of the term referred to the future use of the building. A demolition of the present structure to make way for new construction is proven to hurt the environment now. Adaptive reuse is the process of reusing an existing building and adapting it to meet new needs. Let’s adapt what is already here for earth’s sake.
One project that will benefit from adaptive reuse is the city’s old public safety building. Instead of a demolition and new construction, Mercedes-Benz of Coral Gables will re-purpose the 1973 brutalist building as the dealership’s new showroom and corporate office. An outcome celebrated by preservation advocates who tirelessly championed to save the iconic building.
An excerpt from the National Trust for Historic Preservation puts in context how new construction adversely affects our planet:
“Arguments that promote a practice of disposable real estate are unsustainable at best and at worst environmentally catastrophic. [There is…] embodied carbon within existing structures, [and] the fact that it can take up to 80 years to offset the carbon debt that is incurred when an existing structure is replaced, even if the new building is highly energy efficient. New buildings…will likely never offset the carbon cost of their construction. We don’t have time to simply build our way to a sustainable future.”
Preservation is not only about saving old places, it is an integral component in saving our planet. Let’s be nice to Mother Nature. Or she will not be nice to us.