Sustainable design used to be an option, but now it's often the law with education leading the way. A great example is California's CALGreen, effective in January 2011, which requires new buildings to be energy-efficient and environmentally responsible.
In 1998 when the U.S. Green Building Council (USGBC) created its Leadership in Energy and Environmental Design (LEED) program, “building green” was more conceptual than reality. Today LEED has expanded from one classification to nine classifications, including LEED-Schools. And with the creation of the Collaborative for High Performance Schools (CHPS) in Southern California in 1999, sustainability is the standard, not the exception.
In 2006, 12% of all LEED-certified projects were in education. As of 2008, says author and consultant Jerry Yudelson, “educational construction, estimated at $125 billion...is the largest single market sector in the building industry.” Polished concrete (chemically densified and polished concrete) provides an irreplaceable ingredient in this quest for sustainable, high-performing, and manageable buildings.
Polished concrete is green, whether in new construction or renovation projects. By utilizing concrete as the finished floor, the owner, architect, and general contractor are provided with the optimum foundation to build green. Architects and school officials involved in LEED Gold and Platinum education projects consistently refer to durable, long-lasting, thermal mass, daylighting, and maintenance costs when describing why they specify polished concrete.
The architect specified polished concrete for 70% of the lobby, galleries, and corridors of the new student center at Manhattanville College in Purchase, N.Y. The building was a Green Judges Choice Winner in the 2008 Green Education Design Showcase.
While there are parallels between USGBC's LEED program and CHPS, the latter was created to address the members' frustrations with the high costs, extreme paper requirements, greater bureaucracy, and lack of an education focus that existed with USGBC.
CHPS has expanded to 11 states with two options: verified–where an independent third party confirms that a project has met its stated goals; and designed–a self-certification process. The first is generally required when the school will receive added funding benefits from the local, state, or federal government, while the second is philosophy-driven. CHPS also allows for regional influences within each state's process, something LEED does not. The associated cost of CHPS is also less for both the building owner and the vendor who supplies goods.
For the LEED process, certification of a building is completed by accumulating points through credits. Remember, individual products or processes do not receive points, nor can they be called LEED-certified. They can only contribute toward earning of individual points within the classifications.
The following examples demonstrate the areas architects and school officials generally consider when identifying potential for LEED contributions:
- Materials & Resources - this can cover credits ranging from Building Reuse to Recycled Content and Regional Materials
- Indoor Environmental Quality
- Innovation in Design
- Energy and Atmosphere
At Manhattanville College in Purchase, N.Y., the school's architect, Peter Gisolfi Associates, of Hastingszon-Hudson, N.Y., chose to continue an earlier trend of theirs: specifying polished concrete within educational facilities which they designed. This design philosophy, along with the college's support, led to LEED Gold certification.
“About 70% of the new Richard A. Berman Student Center has polished concrete floors,” says Peter Gisolfi. “Polished concrete is used throughout the lobby, the galleries, and the corridors.”
“It is part of a wide tapestry of environmental accomplishments on our campus,” adds Molly Easo Smith, the incoming president of the college. The 33,000-square-foot Student Center was a Green Judges Choice Winner in the 2008 Green Education Design Showcase. Polished concrete added toward credits within Material and sources criteria on this project.
“Polished concrete is a simple, natural product that can be obtained locally,” says Gisolfi. “It contains no glue or finishes, and it is easy to maintain. In addition, it contributes to the high thermal mass of the building which affects the interior climate of the building positively.” Joseph Coniglio, of Specialized Services of Long Island City, N.Y., was the certified RetroPlate applicator who performed this work.
While it is natural to polish new or existing concrete, the availability of a portland cement-based overlayment that mimics traditional cementitious terrazzo, but at a lower cost, was a product 10 years in the making. It is necessary to know the difference between the calcium aluminate that other overlayments utilize and the portland cement-based Deco-Pour by RetroPlate.
Calcium aluminate, which has replaced the portland cement, does not produce the calcium hydroxide that is necessary for a chemical reaction with a chemical densifier, creating calcium silicate hydrate (CSH). Without CSH there can be no densification, so you do not eliminate the natural dusting of concrete, nor do you increase the strength and repellency of the floor.
A total of 12,000 square feet of concrete corridors, lobbies, and stairs at Laura Angst Hall on the Skagit Valley College campus in Mt. Vernon, Wash., was polished. The college earned Platinum LEED designation.
Skagit Valley College
As part of the new Laura Angst Hall on the Skagit Valley College campus in Mt. Vernon, Wash., the school's architect, Schreiber Starling & Lane Architects, of Seattle, specified 12,000 square feet of Deco-Pour by RetroPlate in terrazzo form with a white base color for the corridors, lobbies, and stairs.
When first created, Deco-Pour was specified as a fix over existing slabs. Today it is specified to either provide the consistent “portland cement with fines” appearance, or to mimic a cementitious terrazzo, as was done here. The Deco-Pour terrazzo was specified as an approved alternate and was to provide the aesthetics and performance of a densified and polished cementitious terrazzo, but at only half the expense.
Washington requires new buildings earn a minimum of Silver LEED designation; Skagit Valley College earned Platinum. Keith Schreiber looked for a product that would be long-lived, low-maintenance, and regionally manufactured. With this project, Schreiber and associate architects, Yost Grube Hall, of Portland, Ore., achieved function and design by including recycled glass, raising the recycled content to more than 50%. Harvey Construction, of Snohomish, Wash., was the contractor.
When considering specifying and installing any polished concrete—whether new, existing, or an overlayment—spell out the expectations of all involved parties. On both of these projects, when asked if they would write the same specification again, both firms said, yes.
Both architects addressed the importance of being explicit when establishing edge and corner finishing expectations. Education and LEED or CHPS go hand-in-hand. Finally, just because the floor is finished, and the building is occupied, you're not done if you have not specified a maintenance program to guarantee long-term satisfaction with your investment.