With sustainability one of the hottest topics right now, more and more municipalities and private companies are requiring sustainable designs for their new buildings as well as their existing facilities. Some of these requirements include Leadership in Energy and Environmental Design (LEED®) certification.
A United States Green Building Council (USGBC) program, LEED provides criteria by which to evaluate buildings consistently for sustainable practices, to promote integrated and whole building design practices, to raise awareness of environmental design and engineering practices that can be implemented and to encourage sensitivity to the environment.
One tool for measuring sustainable or "green" aspects of a building design is through the LEED-NC (New Construction) process. The rating system developed by the USGBC evaluates a building and its site on six sustainable categories: Sustainable Sites, Water Efficiency, Energy & Atmosphere, Materials & Resources, Indoor Environmental Quality and Innovation & Design. And within these categories a project can earn credits and points.
With integration as its cornerstone, the LEED process is consistent with design-build. The benefit of having the owner, contractor, designer and, ideally, the specialty contractors working together from the inception of the project has proved itself for many years. And this should be the same for the LEED process.
LEED-NC has a total possible 69 points, and of those, 27 are reliant on the contractor providing documentation to fulfill the criteria. Not only must a qualifying project achieve so many points for certification, but within those points the project must meet all of the prerequisites in order to even proceed with certification. Of the nine prerequisites required, two are achieved upon completion of construction.
For example, Sustainable Sites Prerequisite 1 - Construction Activity Pollution Prevention - requires that the contractor "create and implement an Erosion and Sedimentation Control (ESC) Plan for all construction activities."
Having the contractor, designer and owner all at the table from a project's beginning can provide a better value in determining the LEED credits to pursue, which fit with the owner's sustainability goals, and meets their environmental stewardship responsibilities. Establishing early LEED process costs begins the documentation process as early as possible as well, critical for maintaining the schedule and the budget. As a result, design-build is arguably the best delivery method for such a project.
LEED certification, especially Gold and Platinum levels, isn't easy and really requires a very holistic design and construction approach. Beginning with the end in mind is a concept shared by both LEED and design-build: They allow building facilities that will last for generations, are sensitive to the environment, are adaptable to several uses over time and minimize energy consumption.
For example, to meet one of the Energy & Atmosphere credits of 14 percent energy performance improvement over ASHRAE/IESNA Standard 90.1-2004, it requires innovation and creative engineering. The contractor and specialty contractor can assist with this early in the design process by providing options and products that the designer and engineers may not be aware of, including the cost impacts to the project. Another example is in the selection and use of regional materials. The designer can put in the specification to buy as many materials regionally that meet the criteria for this credit, but ultimately it is in the hands of the contractor and specialty contractor to determine if what they have purchased through the life of the project meets the criteria.
The same is true of recycled materials. The percentages of recycled materials required to meet the criteria for recycled content can not be determined until the final products are purchased and their individual percentage of recycled content is included.
With design-build's ability to set a price for the project in the proposal stage and track costs continually throughout the design process, value engineering occurs simultaneously throughout the design rather than at the completion of the design. This careful tracking and constant communication, if used effectively, enhances the design.
This is also true of incorporating the LEED process into the project. As the design progresses and credits are validated, the costs can be evaluated for their appropriateness. It may be determined that credits identified in the initial concept design can not be achieved based on the overall cost of the project.
For example, the original proposal may indicate that the project will purchase "green power" but as the design progresses it is determined that the money associated with this credit would be better spent on a more efficient HVAC system.
In summary, with the involvement of the contractor at the early stages of the design process the certainty of achieving the desired LEED certification level should be more accurate and realistic.
Without this involvement, the owner and designer are really leaving the success of achieving LEED certification to the contractor, and of course USGBC.
The emphasis on an integrated team, both by design-build and LEED, is to deliver a successful project that meets the owner's needs, addresses environmental responsibilities and provides the best value within the budget and for the life of the building.
Wendy Hageman is a project manager at Burns & McDonnell responsible for managing the preparation of design-build RFPs, design-build projects and municipal projects. She is the vice president/president elect for the DBIA Mid-America Region.