IGCC short on resiliency, core and shell requirements
- Published: Monday, 30 July 2012 13:40
- Written by CP Staff
The 2012 edition of the International Green Construction Code (IGCC) provides specific criteria for building design and construction that are suitable or even favorable for the use of concrete, concrete products and masonry. However, the IGCC is remiss in that it does not adequately encourage or require the building core and shell to be adequately resilient to achieve good sustainable building design.
For the most part, the code does not address the need of a stronger, more durable, more robust and longer-lasting building core and shell as a prerequisite to adding green features such as low-flow plumbing fixtures or energy efficienct lighting, appliances and equipment. The latter are typically swapped out multiple times over the life of a building, providing many opportunities for improvement, yet the core and shell are rarely upgraded.
Priorities may have been misplaced and this is especially true in disaster-prone areas, found virtually anywhere in the United States. When disaster occurs, if the building cores and shells are not adequately resilient, the property loss tends to be very high. Regardless of whether plumbing fixtures, lighting, equipment, or appliances are conventional or high-efficiency, if they become irreparable or contaminated during disasters, they are landfill-bound along with other building components and contents.
Further, there will be increased costs for design, purchase, construction, and installation of high-efficiency components, equipment, appliances and systems. History has demonstrated that these cost increases drive owners toward more Type V construction. This was experienced with the adoption of energy conservation codes in the 1980s and 1990s.
The more onerous prescriptive thermal resistance insulation requirements, which did not adequately account for the benefits of thermal mass, placed a hardship on concrete and masonry interests and discouraged designers from selecting more energy efficient building designs that utilize passive solar, natural ventilation, peak load reduction and shifting, plus radiant systems to optimize efficiency and comfort.
This was compounded by the increased design and construction costs for all building types, thus encouraging more owners to accept the Type V construction—the minimum type legally permitted by the building code. The trend toward more Type V construction was to offset the initial cost increases associated with the mandatory energy conservation measures.
Minimum code has become the standard of practice in the United States for the design and construction of buildings, other than owner-occupied, -designed and -built. Without the needed criteria for enhanced resilience, these additional costs will drive builders and developers to more extensive use of Type V construction, placing communities at an increased risk when disasters occur. In addition, the less robust Type V construction tends to be less durable and has long-term impacts on community residents, businesses, and revenue.
The 2012 IGCC also does not adequately reward optimized density. A high-rise condominium built to the International Building Code and referenced codes and standards will tend to be far more energy efficient per dwelling unit than mid-rise construction designed and built in accordance with the IGCC. In addition, the occupants in the high-rise building will be provided with Type I, the most robust type of construction, while those in the mid-rise building will likely be provided with a lesser type of construction, potentially Type V.
Jurisdictions adopting the IGCC should also consider criteria for enhanced resiliency. Like the green building design and construction features, they add to initial project costs, but will provide significant long-term benefits to the community and minimize losses, recovery time, emergency response, and disposal of damaged building materials and contents when disasters occur.
Jurisdictions interested in integrating a level of enhanced resilience may do so by adopting Appendix E as a further modification to the IGCC. Its requirements are founded on the basic concepts of the National Institute of Building Sciences and Sustainable Building Industries Council Whole Building Design Guidelines and the specific criteria endorsed by the Institute for Business and Home Safety. The overall approach of the Whole Building Design Guidelines is to integrate Accessibility, Historic Preservation, Aesthetics, Productivity, Cost-Effectiveness, Security and Safety, Functionality and Operability, and Sustainability.
Appendix E is a compilation of recommended code criteria developed by the Portland Cement Association (PCA), and is not currently part of the IGCC. During the scoping sessions for the IGCC, it was determined that enhanced resilience would not be considered. PCA submitted code change proposals during the code development hearings, but the criteria were again denied. State and local jurisdictions are considering criteria for enhanced resilience. The state of Georgia is developing criteria for one- and two-family dwellings under a grant from HUD. On last repost, their criteria were being modeled after the Appendix E criteria developed by PCA.
Specific requirements are based on recommendations endorsed by the Institute for Business and Home Safety (IBHS), the national association representing insurance interests and supporting material-neutral solutions to achieve enhanced resilience for better buildings. Building cores and shells that are more robust, durable, and disaster resistant with long design service lives are clearly more sustainable. Less energy and materials are required for routine maintenance, repairs, and removal and replacement of components.
Any jurisdiction considering the adoption of the IGCC with the intention of obtaining more sustainable buildings in their communities should also consider including Appendix E, especially if the jurisdiction is in a disaster prone area, whether it be hail storm, wind storm, tornado, flood, earthquake, snow storm, terrorism, or accidental catastrophe.
Adapted from "IGCC: Pearl or Peril? An overview of the potential impacts on the use of concrete, concrete products, and masonry" by Stephen Szoke, P.E. FACI, LEED/AP, Portland Cement Association–Director, Codes and Standards