Structural engineers are familiar with the U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED) rating system, but many are not as familiar with the Green Globes rating system. The Green Building Initiative (GBI) is a not-for-profit organization whose mission is to accelerate the adoption of building practices that result in energy-efficient, healthier, and environmentally sustainable buildings by promoting credible and practical green building approaches for residential and commercial construction.
According to its website, GBI was originally conceived as a way to bring green building into the mainstream by helping local Home Builder Associations (HBAs) develop green building programs modeled after the National Association of Home Builders’ (NAHB) Model Green Home Building Guidelines. While developing a strategic partnership with the NAHB, an opportunity emerged to bring a revolutionary learning tool developed in Canada to commercial builders in the United States. Near the end of 2004, the GBI finalized an agreement to bring the Green Globes environmental assessment and rating tool into the United States.
This article provides an overview of the Green Globes system and its similarities and differences from LEED. Although the scope of Green Globes is similar to that of other rating systems such as LEED, users will interact with Green Globes in a fundamentally different manner. The most noticeable difference is that Green Globes was built from the ground up to be an interactive, web-based, sustainability assessment tool. Its primary mission is to serve as a design tool — suggesting improvements and guiding the integration of green principles throughout the design process. This is accomplished through use of software tools designed for Green Globes and provided to the design team, such as the Green Globes LCA Credit Calculator for Building Assemblies and the Green Globes Water Consumption Calculator. More detailed information is available at www.thegbi.org The ANSI consensus-approved version is nearly complete and will be available later this year at www.ansi.org
Assessment and certification processes
As with other rating systems such as LEED, there are four “achievement levels” (one to four Green Globes). Typically, Green Globes tools are first used for web-based self-assessment during the conceptual and design phases. This provides the design team with immediate feedback on the sustainability implications of each project design decision. Once the online questionnaire is completed at the construction documents stage, and a minimum threshold score is met, the building project is eligible for an independent third-party review and site assessment that leads to a formal Green Globes certified rating.
Green Globes evaluates a project in seven primary areas: Energy (30 percent), Indoor Environment (16 percent), Resources (14 percent), Water (13 percent), Site (12 percent), Project Management (10 percent), and Emissions (5 percent). For example, the provisions related to Project Management, including points awarded for commissioning of the structural system, are unique in green building rating systems today. Commissioning is conducted in the pre-design, design, and construction phases in accordance with ASHRAE Guideline 0-05 and points are awarded for various levels of compliance. Other sections that are important to overall project sustainability — site development, energy considerations, and water consumption — are addressed by Green Globes, but since they are not the primary responsibility of the structural engineer, they are not covered in this article.
Generally, the focus of the structural engineer is related to design decisions covered within Resources. As an example, Green Globes allows the design team to opt for a performance path (33 points) or a prescriptive path (22 points).
The Green Globes Rating System provides the design team with an ANSI consensus-based alternative to the LEED series of rating systems. In addition to Green Globes for New Construction/Major Renovations, there is also a module for Continual Improvement of Existing Buildings. Case studies are available online at www.thegbi.org/commercial/about-green-globes/case-studies.asp
David S. Gromala, P.E., has been active in codes and standards development (ICC, ISO, ASCE, ASTM, AF&PA) for several decades and is a member of the ASCE-SEI Sustainability Committee. He is focusing currently on the topics of green building and sustainability, primarily through the ASCE and ASTM Sustainability Committees and the ICC Evaluation Service Sustainable Attribute Verification Evaluation (SAVE) Program. He can be reached at email@example.com. The SEI Sustainability Committee website is www.seinstitute.org/committees/sustainable.cfm.