CREJ

March 2020 \ BUILDING DIALOGUE \ 41 ELEMENTS Carbon carbon emissions compared to the construction of new build- ings, especially if foundations and structures are preserved. When redeveloping the Buffalo Bayou, bids had already been solicited todemolish the cityofHouston’s defunct under- ground drinkingwater reservoir and build a parking structure instead. Page and SWA proposed to repurpose the voluminous concrete space as a visitor destination that could accommo- date installation art – particularly light and sound. The Cistern nowreceivesmorethan35,000visitorsayearandthe61million pounds of concrete, representing nearly 8.3 million pounds of embodied carbon dioxide, was preserved in place. Second, focus on carbon reduction for structure and enve- lope materials. These “heavier” building materials represent around 80 percent of the entire carbon footprint of a building andhave thehighest opportunity for savings.Workwithstruc- tural engineers who have signed the SE 2050 challenge who will be more attuned to evaluating structural system options based on embodied carbon impact. Maximize structural effi- ciencies andspecifyhighrecycledcontent incement andsteel. Workingwithdeveloper Trammel CrowCos.,wearebuilding oneof the cityof Austin’s largest officebuildings. Inaddition to significant collection and reuse of water on the site, we main- tained the existing early 20th century post office for reuse as a food court as an extension of our building’s lobby. The adap- tive reuse of that building inaddition to improvements in con- cretemix design for the towers, resulted in a 20% reduction in embodied carbon over conventional practices (as well as a re- duction of 12% to 25% in the other five environmental impact categories LEEDv4measures). Designtominimizewaste. Interiorsofbuildingsarereplaced on average every 10 years, which over time, represent an enor- mous embodied carbon impact. Selecting products with high recycled content within them is a good place to start. Also selecting products that have takeback programs is critical to reducing embodied energy and helps support manufacturers who are taking responsibility for theirmanufacturingprocess- es and extending their material’s useful life in a more circular economy. Track the embodied carbon in thematerials of your build- ings. Just like adding nutrition labels transformed the way we looked at our food, being transparent about the envi- ronmental impact of our materials will help us make more informed decisions. Ask for Environmental Product Decla- rations from manufacturers, use free tools like EC3 for ear- ly material analysis or Tally to conduct Revit-based carbon analysis, use the AIA’s Large FirmRound Table’s Countdown on Carbon guide, and sign up for the Embodied Carbon Net- work to stay up to date with other trying to tackle these issues. In 2019, the AEC industries acknowledged the role our work plays in climate change. May 2020 be the year we all start doing something about it. \\ jkurtz@pagethink.com