Education institutions have become leading proponents of sustainable design and construction practices. Driving their commitment is the desire to foster healthier learning environments, promote environmental stewardship and increase operational efficiency. More education institutions are seeking certification under the Leadership in Energy and Environmental Design (LEED) Green Building Rating System, and they are looking to their architects, engineers and constructors to optimize the environmental performance of their projects, and deliver them in a timely and cost-effective manner.
The U.S. Green Building Council (USGBC) developed the LEED Rating System as a voluntary national standard for sustainable, high-performance buildings. Several different LEED applications address unique project types, but LEED for New Construction (LEED NC) is the most commonly used. LEED NC consists of seven prerequisites and 69 potential credits in six categories: Sustainable Sites (SS); Water Efficiency (WE); Energy & Atmosphere (EA); Materials & Resources (MR); Indoor Environmental Quality (EQ); and an open category, Innovation & Design Process (ID). LEED NC offers four certification levels; basic certification requires a minimum of 26 credits. Since the release of LEED 1.0 in 1998, more than 1,775 projects have registered under LEED guidelines; the 154 projects that have earned certification represent more than 216 million square feet of built environment. Education facilities make up almost one-quarter of all LEED projects.
Each education project requires careful analysis to identify the best-value approach to pursuing LEED credits. The requirements, cost and effectiveness of each credit must be evaluated in the context of a project's budget and program targets. Following are challenges and strategies to stimulate the planning process for project teams:
- Sustainable Sites
As a prerequisite under Sustainable Sites, LEED requires an EPA-compliant erosion and sedimentation control plan. Credits are awarded for selecting a building site that protects or restores open space, is accessible to public transportation, manages stormwater, reduces “heat-island” effects and controls light pollution.
Sites typically are chosen before the architect and construction manager are selected, so many SS credits are gained or lost before the project team is assembled. Therefore, it may be beneficial for schools to bring in an architect, engineer or builder with LEED expertise to perform a feasibility study at the site-selection phase.
- Water Efficiency
LEED promotes water-use reduction through resourceful landscaping, wastewater technologies and high-efficiency plumbing design.
A simplified landscaping plan, with drought-tolerant native plants, reduced use of sod, and high-efficiency irrigation (e.g., drip hoses) can be an attractive, cost-effective design. However, many administrators, particularly in university settings, want lush landscaping to enhance the visual impact of a high-profile building. An effective, yet more costly, irrigation strategy is a rainwater or gray-water collection system, such as a cistern.
Water-use reductions of 20 percent or more can be achieved by installing high-efficiency plumbing fixtures, such as low-flow lavatory faucets and toilets, and waterless urinals. However, building owners must understand and comply with maintenance requirements. For those unsure about adopting these new technologies, flexibility can be incorporated into the plumbing design. Although it eliminates any cost savings from simplified plumbing requirements, supply piping can be installed in walls behind waterless urinals to enable change-out in the future if maintenance issues arise.
- Energy & Atmosphere
EA prerequisites include building commissioning, compliance with the American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) 90.1-1999 energy performance standard, and chlorofluorocarbon (CFC) reduction in HVAC equipment.
Commissioning is used on many projects, especially laboratory and healthcare facilities with complex MEP systems. For smaller or more traditional facilities, it may be hard to justify the added cost of commissioning. Tailoring the scope of commissioning services to focus on critical systems, such as the air-handlers or the exterior building envelope, is an effective way to maximize performance and value.
Those institutions that have central chiller plants with CFC-based refrigerants may find CFC reduction to be a more difficult prerequisite to achieve. Owners should evaluate their equipment in the earliest stages of planning to determine if remedial work is needed to satisfy this requirement.
EA credits are awarded for reducing energy consumption, and for using renewable or low-impact sources to provide part of the building's energy load. Energy use can be reduced 15 to 25 percent through “right-sized” air-handling systems, an efficient building envelope and glazing, and energy-saving features such as occupant sensors for lighting control.
- Materials & Resources
Storage and collection of recyclables is required under the MR category. Credits in this category include building and resource reuse, construction waste management, and use of recycled or renewable materials, local and regional materials, and wood products certified by the Forest Stewardship Council (FSC).
Construction waste management means diverting construction debris from landfills. As tipping fees continue to rise, this practice actually can result in cost savings. Mulching trees or shrubs that have been cleared from the site, and reusing demolished asphalt or concrete as road base can increase the percentage of waste diverted.
With the exception of certified wood products, which tend to cost more than their non-certified counterparts, materials satisfying the MR credits come with little or no additional cost. Structural steel, building insulation, ceiling tile and carpeting all contain high recycled content, and locally available materials can be found if project teams seek them out. As such, the challenge in achieving these credits is not merely finding suitable materials, but ensuring that adequate documentation is provided to substantiate them. This documentation process can be demanding and should begin as early as possible.
- Indoor Environmental Quality
LEED projects must meet the minimum indoor air quality (IAQ) performance standards of ASHRAE 62-1999, which has become a common design standard, and includes prohibiting or controlling smoking within the building. The IAQ category awards credits for building features such as carbon-dioxide monitoring, ventilation effectiveness, construction IAQ management, and use of low-emitting paints, adhesives, carpet and composite wood.
Carbon-dioxide monitoring requires that exterior sensors be installed in line with the air handlers and integrated into the building-control system. Ventilation effectiveness is achieved via operable windows or alternative ventilation systems such as underfloor or high-velocity supplies. Schools should work with their MEP designers during project planning to evaluate design alternatives.
IAQ construction-management plans include protection of ductwork from contamination that might result from debris, dust and mold during construction, and proper housekeeping to minimize dispersal of airborne contaminants. These procedures generally do not add to the capital cost of a project, but do require proper construction sequencing and monitoring.
IAQ management before occupancy can be achieved with a two-week period of flushing the mechanical system with 100 percent outside air, or through a baseline IAQ testing protocol. Flush-out is the more cost-effective approach provided time is allotted in the schedule and excess humidity from the outside air is not a concern. IAQ testing will add to a project's costs. These costs are based on the number of testing points within the building, and the quantity and placement of testing points is dependent on the size and program of the facility.
Low-emitting paints, adhesives and sealants are available at no additional cost; low-emitting composite wood products are more difficult to incorporate. Some products are available, but their long-term performance is somewhat unsubstantiated. Achieving these credits requires the preparation of volatile organic compound (VOC) budgets for each material to document its IAQ performance.
- Innovation & Design Process
Finally, up to four credits are awarded for innovative design and construction features that go “above and beyond” the existing LEED requirements. An additional credit is awarded for including a LEED-accredited professional on the project team.
A common ID credit is the development of an Active Education Component, featuring signage, tours or a case study, to illustrate and inform visitors about sustainable features and benefits.
The most critical driver to LEED success is the spirit of collaboration that exists on the project team. Education institutions should evaluate their project-delivery approach to promote greater coordination and trust among the design and construction team. Traditional general contracting, characterized by lump-sum, single-prime bidding is not the optimal project-delivery method for LEED projects.
The construction-management (CM) approach, in which the builder is brought on board before the start of design, can be a more attractive model. This delivery method affords the benefit of the CM's expertise in budgeting, scheduling, value analysis, and constructability reviews. It ensures that the design progresses within the established budget, and that potential dilemmas are identified and resolved before construction is underway. The benefits extend to the LEED process as well. Design and cost scenarios can be developed for a number of credits, which affords a school the option to “pick and choose” credits that provide the best value or performance.
Finally, the role of the school itself in LEED certification should not be underestimated. Although the design and construction team provides technical advice, the school must communicate clearly the project objectives that drive the process and hold team members accountable.
Gourley is senior project engineer, LEED-accredited professional, for Skanska USA Building, Inc., Durham, N.C.
Duke University aims for silver
Duke University's newest addition to its Pratt School of Engineering is the Fitzpatrick Center for Interdisciplinary Engineering, Medicine, and Applied Sciences (CIEMAS). It supports teaching and research in healthcare, genomics and biotechnology. CIEMAS has undergraduate teaching and project labs, research facilities for bioengineering, photonics/communication systems, integrated sensors/simulators and materials sciences/engineering, as well as faculty and student meeting spaces.
At 322,000 square feet, the $97 million complex more than doubles the Pratt School's teaching and laboratory space. Construction was completed on schedule last August. Aiming for LEED Silver certification, CIEMAS includes:
Custom air-handling units “right-sized” for the zones they serve, heat-recovery wheels and variable-frequency drives to optimize energy performance.
A 70,000-gallon irrigation cistern and high-efficiency plumbing fixtures that reduce potable water use by 65 percent.
Architectural woodwork and laboratory casework made from FSC-certified quarter-sawn cherry.
Exterior stair towers and sidewalls of “Duke Stone,” quarried from a university-owned source.
For the project, the construction team helped develop LEEDBuilder, a web-based information tool designed for the LEED Rating System, that can facilitate collaborative communication, document management and the reporting process for projects pursuing LEED certification. LEEDBuilder is a platform through which all members of the project team can develop, document and report all information prescribed by the LEED framework.
CIEMAS has set a standard for subsequent Duke University projects that are pursuing LEED certification.