Determining the lowest-cost points in the Leadership in Energy and Environmental Design Green Building Rating System
Much has been written about the U.S. Green Building Council's (USGBC's) Leadership in Energy and Environmental Design (LEED) Green Building Rating System — the “voluntary, consensus-based national standard for developing high-performance, sustainable buildings”1 — and why building owners and the design and construction communities should embrace it. Now, studies and reports identifying the cost of achieving a LEED rating are starting to emerge.
Of the many points a project can earn toward LEED certification, some are pursued almost universally. These could be called the lowest-cost points. Some owners and designers have learned which points these are through careful study of LEED, while others have learned through trial and error. This article will discuss ways to determine the lowest-cost points and ensure they are achieved. The article also will discuss how to identify points “left on the table” by LEED project teams.
Keys to achieving a “low-cost” LEED project include:
Developing clear, realistic goals at the project's inception.
Assessing the design team's abilities.
Investigating local codes and regulations.
Establishing the desired LEED level early and maintaining focus on it.
Conducting LEED design reviews at each stage of design and developing “LEED-friendly” specifications.
The development of clear, realistic goals should be treated in much the same manner and during the same period of time as architectural programming. Think of each LEED point as a child's building block. Organize the blocks into groups: points most worth pursuing, points possibly worth pursuing, points to continue considering, and points least worth pursuing. Experimenting with different combinations of blocks will result in an architectural program with LEED integrated into it, rather than one for which LEED is an afterthought.
The pursuit of LEED points often entails consideration of issues that may not appear obvious at first. For example, great daylighting, which involves more than additional glazing and locating occupants near windows, impacts HVAC-equipment size and may require automatic controls. During programming, the owner needs to understand the importance of these considerations, even though equipment will not be sized and systems designed until later. The owner's programmatic requirements may prove better-suited to a good-daylighting design than a great one, if site configuration and the desire for a dense development turn out to be limiting factors.
Know what the design team is capable of. Do not program into a project LEED measures that cannot be designed and/or documented properly. For instance, for a 20-story commercial tower built to the lot line, do not expect a photovoltaic (PV) system to be installed on the roof and provide 30 percent of the energy demand to help you earn several LEED energy points. There simply is not enough roof area. Installing PV panels on the exterior walls would cost more and require more area because the panels would receive less solar energy annually.
LEED certifications do not just “happen.” Owners are advised to put someone in charge of managing the LEED process and keeping everyone on track. This person should understand LEED and the design process well enough to discern whether a designer's explanation of how a system works and why it is consistent with LEED requirements is solid.
Before falling deeply in love with the LEED points you elect to pursue, make sure you have taken into account local codes and regulations. In many cases, LEED points that appear difficult to attain are, in fact, easy because they are required or almost required by local codes. For example, ductwork adhesives and sealants with volatile-organic-compound (VOC) levels lower than the one required by LEED are available. Your local jurisdiction might require you to use these lower-VOC products.
On the other hand, some LEED points thought to be cost-effective to pursue might violate local regulations. For instance, no-water urinals, which go a long way toward meeting LEED requirements for water-use reduction, might not be allowed by your local building code, which may state that urinals must use 1 gal. of water per flush. Your choices are to eliminate no-water urinals from consideration or fight a long battle with the local building department. If you choose to fight, the plumbing contactor, with the backing of the local plumbers union, may charge for equipment he or she otherwise would be installing, such as flush valves and supply-water piping.
There are four levels of LEED certification: Certified (26 to 32 points), Silver (33 to 38 points), Gold (39 to 51 points), and Platinum (52 to 69 points). As the level of LEED increases, so does the amount of work required to achieve it (Figure 1). That is not necessarily the case with cost, however. If the cost of going from Certified to Silver is $20,000, the cost of going from Silver to Gold will not necessarily be another $20,000. That cost will depend in part on the project goals, the design team's abilities, and local codes and regulations. Make sure increased costs are understood before deciding which LEED level to pursue. Failure to fully comprehend cost impacts could lead to an owner not getting what he or she paid for and, as a result, litigation. Be realistic about what you can achieve. It is better to require a Silver rating and achieve a Gold than to require a Gold and achieve a Silver.
Do not overlook Innovation & Design points. Easier to obtain than most people realize, they are awarded for “exemplary performance,” defined as performance at least one step size beyond the requirements of certain LEED credits. For instance, in LEED-NC, points are awarded for water-use reductions of 20 percent and 30 percent. The difference between these two levels, or step size, is 10, making the next step up from 30 percent and, thus, the threshold for earning an Innovation & Design point 40 percent. If your project uses reclaimed water for the flushing of water closets and urinals, then showing a water-use reduction of at least 40 percent should be easy.
Step changes can be thought of as rungs on a ladder, with each rung requiring a similar level of effort to reach. The exception concerns the LEED-NC credit for renewable energy generated on site, which awards points for performance of 5, 10, and 20 percent; exemplary performance is defined as 40 percent. With the innovation threshold so high, few owners seem to want to make the additional capital investment required to generate renewable energy on site. Indeed, 5-, 10-, and 20-percent performance has been achieved on only 15, 12, and 11 of 128 projects, respectively, while 40-percent performance has been achieved on only four.
Design reviews are critical to achieving a desired LEED rating. These reviews should occur at the conclusion of the programming, schematic-design (SD), design-development (DD), and various construction-document (CD) phases. Understand when certain work needs to be done. For instance, carbon-dioxide monitoring should be part of the final CD package. If LEED points for optimizing energy efficiency are expected, energy modeling needs to take place during the SD phase of a project, as optimization can have a major impact on equipment selection. If an owner wants to maximize energy efficiency, he or she should hire an expert who specializes in that type of work and has a proven track record.
Standard project specifications are not particularly LEED-friendly. For instance, mechanical contractors cannot be expected to install MERV 13 filtration tested per ANSI/ASHRAE Standard 52.2-1999, Method of Testing General Ventilation Air-Cleaning Devices for Removal Efficiency by Particle Size, if a specification states that filters are to be 60-percent efficient based on ANSI/ASHRAE Standard 52.1-1992, Gravimetric and Dust-Spot Procedures for Testing Air-Cleaning Devices Used in General Ventilation for Removing Particulate Matter.
Make sure mechanical and electrical specifications include VOC limits for adhesives and sealants. To avoid having to issue a change order later and risk losing a LEED point, make sure they are included in final construction documents as well.
Before committing to the pursuit of a particular LEED rating, consider the project goals, assess the design team's abilities, understand local codes and regulations, and know what is happening in the local construction market. Remember to check for the inclusion of LEED requirements on design documents and in project specifications, and try to claim every innovation point possible.
U.S. Green Building Council Website, www.usgbc.org.
Kats, G., Alevantis, L., Berman, A., Mills, E., & Perlman, J. (2003, October). The costs and financial benefits of green buildings: a report to California's Sustainable Building Task Force. Available at http://www.ciwmb.ca.gov/greenbuilding/Design/CostBenefit/Report.pdf
Matthiessen, L.F., & Morris, P. (2004, July). Costing green: a comprehensive cost database and budgeting methodology. Available at http://www.dladamson.com/images/pdf_files/costinggreen.pdf
Amatruda, J., et al. (2004, October). GSA LEED cost study: final report. Available at: http://www.ccb.org/docs/GSAMAN/gsaleed.pdf
Syphers, G., Baum, M., Bouton, D., & Sullens, W. (2003, October). Managing the cost of green buildings: K-12 public schools, research laboratories, public libraries, multi-family affordable housing. Available at http://www.ciwmb.ca.gov/greenbuilding/Design/ManagingCost.pdf
The sole proprietor of Soltierra LLC (www.soltierra.com), a provider of sustainability consulting for the built environment, Hernando Miranda has managed sustainability efforts for nearly 80 LEED projects, nine of which have been certified by LEED, including three that were certified Version 2 Platinum. Miranda is a member of The American Institute of Architects' Top 10 Green Buildings Committee. Formerly, he served as vice chairman of the LEED Indoor Environmental Quality Group, as a member of the LEED Commercial Interiors Core Committee, and as a proxy member of the LEED Steering Committee. He holds a bachelor's degree in mechanical engineering and a master's degree in architecture.
Table 1 lists the 26 most-often-earned LEED points, based on an analysis of the 128 projects certified under versions 2.0 and 2.1 of LEED for New Construction and Major Renovations (LEED-NC).
The reason these points are earned so often is that they are among the least expensive and/or least difficult to attain. In some cases, however, the owner's requirements, the regional climate, site restrictions, and/or local regulations discourage the pursuit of certain of these “easy” points. For example, in wet climates, a rainwater-retention system that can be used to irrigate landscape plantings during dry weeks of summer may be reasonable and cost-effective. In dry climates, however, it may be impractical. Regardless, each of the “easy” points in Table 1 should be evaluated carefully and the ramifications understood before being chosen.
The specifics of a project have tremendous impact on the cost of “going LEED.” For instance, two buildings could be physically identical, with the cost of achieving LEED Gold certification for one an increase in construction cost of less than 1 percent and the cost of achieving LEED Gold certification for the other an increase in construction cost of 10 percent. Accounting for the difference in cost may be the difference in who designed and/or built the buildings, where the buildings are located, and/or when the buildings were built.
Figure 2, from “The Costs and Financial Benefits of Green Buildings: a Report to California's Sustainable Building Task Force,”2 shows that costs tend to increase with LEED rating level. The small size of the statistical sample helps explain why the chart shows that the added cost for a LEED Gold rating is less than the one for a LEED Silver. A more important finding in the report is that, “An up-front investment of about 2 percent of construction costs typically yields life-cycle savings of over 10 times the initial investment.” That should be of great interest to building owners.
Figure 3, from “Costing Green: a Comprehensive Cost Database and Budgeting Methodology,”3 compares the total-construction-cost expectations of more than 100 LEED-rated and non-LEED-rated buildings. It is interesting to note that the LEED-rated buildings are distributed fairly evenly among the non-LEED-rated ones.