Thus, the 8-inch concrete masonry consumes 132 tons less Pc than the 6-inch tilt-up wall. By some measures, that is 165 tons less carbon dioxide. On average, concrete masonry walls require 2.6 pounds less Pc for every square foot of wall area, even at the 8-inch cmu to 6-inch tilt-up comparison.
That difference in CO2 is impressive, but not necessarily the end point. It illustrates the sophistication of a building system that can be overlooked as a holistic contributor. Concrete masonry is viewed differently from the perspective of each discipline – to engineers, a structural or utilitarian element; to energy consultants, a heavy mass wall; to architectural designers, a palette from which to create; to owners, a durable building. In fact, it is all of these.
While the world of architectural products clamors to introduce the latest in green design and technology, giving specifiers a daunting task of filtering out hype from reality, we have been steadily refining a product with a long history. That longevity is not aged or outdated; it is tested, and offers a proven baseline on which to build.
New products marketed for robust sustainability based on a particular feature may not meet all of the requirements for established standards and codes. Such features must be balanced with good old health, safety, and welfare, and assessed within the context of the product's holistic role in the structure. Before specifying products claiming sustainability stardom, project teams must fully vet the proposed material to be certain it meets all criteria — including code-incorporated ASTM standards — required of the products they intend to replace4.
Green building rating system credits often focus on certain product classes and distinct criteria while overlooking the beneficial synergy of building systems such as concrete masonry. While a universal credit for that may not exist in all rating systems, concrete masonry's inherent qualities and functionality support and contribute many of the strategies that are key to sustainable design - energy efficiency from heavy mass walls, low extraction impacts, multiple functions in one element, recycled content, and regionality to list a few.
Parallel to, or beyond, sustainability (depending on the advocate) is resiliency, the paradigm of building for disaster resistance, occupant and structure survivability, and shelter. Concrete masonry contributes substantially to both purposes. Even if incorporated into a project for its sustainable attributes, concrete masonry inherently provides resilient characteristics of durability, strength, seismic performance, airborne debris resistance, and blast and bullet resistance. [See Design for Resilience & Concrete Masonry.]
Concrete masonry is more relevant to sustainable and resiliency goals today than ever, and uniquely offers benefits to multiple disciplines and strategies. It is truly holistic, in and of itself, and within the context of the project. It's optimized now, and is in a great future-forward position to continue to evolve.