Precast concrete is a panelized (or prebuilt) system for poured concrete that has become an alternative building technique in residential construction. The system provides benefits to the architect, builder and consumer. Precast concrete panel systems combine the energy-saving thermal mass qualities of concrete with the ease and assembly speed of a panelized building system. They install quickly, will not warp or rot, and are termite and fire resistant. From a production standpoint alone, this system can save up to three weeks in contrast to typical wood framing techniques.
During the manufacturing process, wall and floor sections are molded and cured in a factory setting, delivered to the project site, and craned into place to create a structural shell and bearing walls. In some applications, these systems are also used to create floor and roof panels. Precast concrete panels are attractive to residential architects and builders for a number of reasons. They allow dimension accuracy, energy code performance, state of the art design drawings and accessible CAD details, quality-controlled manufacturing and certified installation. They are also extremely durable. Studies suggest that precast concrete products can provide a service life in excess of 100 years.
An increasing number of precast panel projects also incorporate a process that adds a continuous layer of rigid foam insulation to the panels to increase thermal resistance, reduce noise and further improve energy-efficiency. As of 2008, precast concrete panels represented an estimated 2.7 percent share of above-grade walls in single-family construction, equaling about 41,000 new homes. Its market share in below-grade foundation applications has remained substantially higher at about 8 percent. Basements made from precast concrete panels can be described as dry, warm and quiet.
Precast concrete panels showcase a number of green and sustainable properties. The system allows for a substantial reduction in on-site waste and optimized material usage. In addition, projects that use this system are increasingly green friendly when panels are fabricated from recycled steel and locally extracted materials. Precast panels can quickly rack up points in the Recycled Content and Local/Regional Materials credit categories of the LEED Green Building Rating System.
Although there are many benefits to precast building system technologies, concrete panels are not yet widely accepted by builders and contractors in the US. The panels require trained installers and special fabrication tools. Additionally, to optimize cost and production efficiency, the system is best applied in neighborhoods of homes with the same floor plan as opposed to a single custom home. However, the system is well positioned to grow in popularity as the residential housing market stabilizes. The demand for energy-efficient housing options will continue to expand as builders also search for ways to build and design more efficiently.
Lindsay Locke is the director of business development for TightLines Designs in Raleigh, N.C. She has ten years of experience in business development and senior leadership in the fields of architectural services and community development. Lindsay frequently lectures on sustainable building topics including alternative building techniques and energy-efficient initiatives and is a LEED Accredited Professional and real estate broker.