Advanced Buildings
Guidebooks can provide more energy-efficient buildings.
FREQUENTLY, A BUILDING’S ENERGY USE IS AN AFTERTHOUGHT IN THE DESIGN PROCESS
Architects design a building that satisfies their client’s programmatic needs and rely on engineers to make the mechanical and electrical systems work. This separation between the two disciplines results in buildings that use excessive amounts of energy and potentially are uncomfortable for occupants. A high-performance building overcomes these obstacles by integrating design processes and setting rigorous performance standards. The result is a reduced impact on the environment.
To assist developers, architects and engineers in creating high-performance, energy-efficient buildings, the Energy Center of Wisconsin (Energy Center), Madison, and New Buildings Institute (NBI), White Salmon, Wash., have developed Advanced Buildings several guidebooks designed to create high-performance buildings across the country.
ADVANCED BUILDINGS
NBI and the Energy Center are mission-driven, nonprofit organizations that care about the building environment. The groups have worked together informally since 2000, but the natural synergies that existed between NBI’s building-science knowledge and the Energy Center’s education and program-development expertise led to the full-scale collaboration that is Advanced Buildings. The Advanced Buildings suite of guidebooks includes a Benefits Guide, Benchmark, Reference Guide, LEED™ Guide, Technical Training Series and a Web site, www.poweryourdesign.com. All guidebooks also are available as PDF files on the site.
Because owners often speak a different language than design teams, the Benefits Guide was created to help architects, engineers and contractors make the business case for constructing high-performance buildings to owners and developers. The guide, which is available as a 47-page book and CD-ROM, provides reasons to build high-performance buildings and the economics behind them. It specifically deals with the myths, design-process changes and benefits high-performance buildings deliver.
Benchmark is a design- and performance-based rating guidebook that offers designers options for delivering high-performance buildings with paybacks of less than five years which achieving 15 to 30 percent energy savings above the ANSI/ASHRAE/IESNA Standard 90, 1-2001. A national committee consisting of manufacturers, contractors, building owners, designers, property managers, government representatives, efficiency experts and members of the public was involved in Benchmark’s year-long development and review process.
Benchmark can be used by itself to attain energy savings, with the U.S. Green Building Council’s (USGBC’s) LEED™ program, the federal government’s ENERGY STAR™ program or incentive programs offered by local utility companies.
Because Advanced Buildings and LEED have a similar mission of fostering sustainability, creating and maintaining the LEED™ Guide was a high priority. The guide explains how to use Benchmark with LEED for New Construction (LEED-NC) v2.1. There are 17 points Benchmark fully addresses, including Energy & Atmosphere, Credit 1 (EA-1) Optimize Energy Performance, which is worth up to 10 points depending on how much more efficient a bulding is compared with a baseline ASHRAE 90.1 building. Four other points partially are addressed, including Sustainable Sites, Credit 8 Light Pollution Reduction. Benchmark also is being proposed by USGBC as a prescriptive path to the LEED-NC EA-1 Credit in v2.2. This would enable design teams to obtain LEED-NC points without having to perform complex building-energy simulations, which take additional time and resources.
The 312-page Reference Guide provides further detail about the credits in Benchmark. For example, Benchmark provides a concise description of design problems, cites the appropriate codes and standards, and sets recommendations for adoption in the final building. Basically, the Reference Guide provides in-depth background to the intent of a Benchmark credit.
A Technical Training Series includes seminars held by the Energy Center and NBI. The seminars explain how to achieve a high-performance project the next time you design or build. Dates, times and location can be found on Advanced Buildings’ Web site. The Web site also provides a full overview of Advanced Buildings’ materials and virtual tours of and case studies about high-performance buildings.
MORE ABOUT BENCHMARK
Benchmark is the cornerstone of Advanced Buildings. Its recommendations revolve around the four basic elements that affect a building’s energy usage: the building envelope, lighting and lighting controls, HVAC equipment and systems, and plug loads. By following Benchmark, designers can achieve measurable human, environmental and economic benefits to building occupants, including improved IAQ, thermal comfort, visual comfort, acoustic comfort, security and safety, and energy efficiency.
Benchmark is divided into the following four parts: Basic Criteria (similar to LEED prerequisites), Prescriptive Criteria, Simulation Criteria and Credit Criteria. The Basic Criteria are climate-specific minimum standards every building should incorporate as common practice. For example, a project must meet ASHRAE 90.1, all fenestration must be National Fenestration Rating Council rated, and construction must meet all standards set by the owner and design team during the design process.
Next, the design team must choose between Prescriptive Criteria and Simulation Criteria. If the design team chooses Prescriptive Criteria, all measures must be followed to meet Benchmark. Some of these measures include heating and cooling efficiencies, maximum lighting power densities and building-envelope performance. As an alternative, the design tem may opt to construct a model of the project in a U.S. Department of Energy-approved energy-simulation program as part of the Simulation Criteria. The Simulation Criteria allow the design team to select only those measures that return the most energy savings for the least cost, as well as evaluate special technologies that are not within the scope of Benchmark.
The Credit Criteria recognize additional performance beyond the required levels for each path. Benefits of adopting the Credit Criteria include a potential to earn additional LEED Credits, increased energy efficiency and increased building performance beyond the 30 percent above the ASHRAE baseline. Some of the strategies in the Credit Criteria include special design considerations for demand-responsive buildings, incorporating task lighting into the ambient lighting scheme and creating a plan for continuous recommissioning.
In addition, Benchmark has standards for Acceptance Testing when a project is complete. Acceptance Testing is a portion of building commissioning and ensures a building performs the way it is designed. These credits are not proprietary and easily can be included in project specifications.
THE BUSINESS CASE
One of the biggest barriers to the implementation of high-performance building measures is up-front cost to an owner. When comparing two buildings, one using ASHRAE 90.1 and one that meets Benchmark, there’s an added cost of approximately $1 per square foot for the benchmark building. About 40 cents of the $1 is an increase in fees for the design team and Acceptance Testing. However, the average savings is 40 cents per year in reduced utility costs. These savings are under a three-year simple payback, the Energy Center has found most owners and developers are comfortable with this rate of return. The cost figures to implement Benchmark are the result of extensive simulations on several commercial building types, such as large and small offices, retail centers and schools, in each major U.S. climate zone.
The designer’s ability to offer economic benefits to an owner is a central feature of the Advanced Buildings materials. Theses benefits often can help owners choose one design team over another and provide repeat business when project goals are verified through Acceptance Testing. Despite the added up-front cost, the Energy Center and NBI have found an integrated approach that occurs early in the design process is critical to providing and efficient building and reducing the amount of costly change orders and value engineering later in the process.
While building energy use may be an afterthought in the design process, it has tremendous impact on our society. Cheap electricity artificially makes conserving energy buildings too expensive by devaluing the energy savings the conservation measures produce. Ironically, offering electricity inexpensively encourages waste, which drives the need to build more generating capacity.
In addition, as long as we rely on fossil fuel to generate electricity, building energy use contributes to the greenhouse gases that are changing our climate. The Advanced Buildings’ guidebooks are the Energy Center and NBI contribution to shifting the market toward more sustainable future.