How to Design a Green Building Within Budget
“How much does LEED cost”? University administrators and facilities directors across the country are grappling with the need to design and construct their buildings sustainably with all the obvious long-term benefits but within their “first cost” budget.
Making smart choices early during the design process and looking for ways to offset those sustainable cost premiums by targeting potential construction savings is one way to afford sustainable strategies. In addition, utilizing a process such as an integrated design process (IDP) allows the team to make smart informed choices balanced by budget and sustainable goals. Applying a constant vigilance on costs throughout the project can lead to both sustainable and financial success.
The following process for achieving high levels of sustainability within budget was successful in two recently completed campus projects. Both are certified as Leadership in Energy & Environmental Design (LEED) Platinum, the highest certification by the United States Green Building Council (USGBC). The key element for consistently achieving such high results is a combination of full commitment to the goal by all stakeholders and a cooperative, integrated multidisciplinary design approach. The University of Texas at Dallas, Student Services Building (UTD) and the Richland College, Sabine Science Hall (RC) are two recent projects designed by Perkins+Will that utilized this approach to achieve LEED Platinum within the original budgets.
An absolute commitment by all stakeholders?owner, program manager, contractor and design team?is essential to achieve a sustainable building, especially one that is delivered within budget. First, all members must be in full agreement and committed to achieving the project’s sustainable goals. Anything less will result in a slow deterioration of goals, yielding lower levels of certification, or worse, no certification at all. Second, each stakeholder entity must have a sustainability champion who promotes sustainable design and activities throughout the project. This is important in maintaining the momentum and focus, especially during the value management stages. The IDP project delivery approach asks all the members of the stakeholders committee to look at the project objectives, building materials, systems, assemblies and budget from different perspectives. This approach capitalizes on the expertise of each respective specialist working together as a team, rather than as isolated individuals.
Define Sustainable Goals Early
The earlier you decide to build green, the more opportunities you will have to maximize the synergies in your building's design and performance while keeping your building within budget. The best green strategies are multi-faceted. We began with a review of the LEED Checklist to determine which points we wanted to pursue. Our goal was to seek as many LEED points as possible to achieve Platinum status. By striving to collect maximum points, the expectation of all stakeholders is set high. In both the UTD and RC LEED Platinum projects, we established the minimum number of points needed to meet the goal, then added ‘contingency points’ to our checklist. The contingency of at least three or four points above the minimum requirement was necessary and included to ensure there were no surprises at the end of the project. The LEED checklist became the project’s “road map” and the team routinely monitors progress toward the goal to ensure complete compliance.
Sustainable Design Charrette
Conducting a sustainable design charrette in a focused and collaborative brainstorming or “think tank” atmosphere is convened at the project start to encourage an open exchange of ideas and information allowing for integrated sustainable design strategies to evolve. All the team stakeholders are encouraged to collectively address problems and offer solutions within and outside their fields of expertise. The charrette is particularly helpful when multiple people represent the interests of the university, which often creates conflicting needs and constituencies. Participants are educated about the issues and resolutions, enabling them to "buy into" sustainable solutions. On UTD, the design charrette established an innovative functional and efficient new space planning protocol by reducing the number of individual offices in favor of open office planning and multi-use shared spaces that lead to a more efficient or “sustainable” use of space. A total of 11,000 square feet was eliminated from the program creating a building that is 73 percent efficient (by ratio of net assignable space to non-assignable space).
Integrated Design Process Delivery Model
The method of delivery and procurement of the project is critical and should be identified as early as possible, preferably during the planning stage of the project. The UTD and RC projects both utilized the Construction Manager-at-Risk (CMAR) delivery model with a Guaranteed Maximum Price (GMP). Based on our experience in delivering LEED projects within budget, we believe it is imperative that the contractor be at the table early during the pre-construction phases to serve as the constructability advisor and cost estimator. A CMAR that brings previous LEED project experience and a sustainability project team leader who can serve as a liaison between the designers and construction team, is beneficial and will lead to project success.
Some owners recently have directed their design teams to design their buildings to a LEED “standard” and forego the documentation process to save the expense of the documentation fees. This approach tends to be shortsighted. The cost savings are minimal and, if budgeted from the start, are inconsequential. The third party verification and commissioning helps ensure that operational goals are met with the construction funds. Keeping the team focused and accountable for their discipline’s sustainable design goals ensures that the project achieves what it set out to do. From a project cost standpoint, the premium for obtaining LEED Platinum certification for UTD and RC was minimal in comparison to the overall total project cost and only represented the labor needed to produce the USGBC submittal.
Balancing the Budget
It is not important to have an exorbitant project budget to attain LEED certification. For both of these case studies, and the UTD project in particular, the owner carried only a normal project budget that was adequate to achieve the programmatic goals. Our Richland project was intended to be a LEED project from its onset; the UTD project became sustainable based on our guidance. In both cases, we worked within the established construction budgets and led our clients through the process of sustainable design.
Next, both the contractor’s and design team’s estimators created independent cost models based on building assemblies. This allowed us to test various design options against their costs, and it permitted a double check on the cost numbers under review. The estimators worked cooperatively to reconcile the construction budget throughout the project’s development. The process lets the team test the value of various options vs. their first cost opportunities. We get early buy-in on the sustainable features while identifying offsetting cost savings to keep the project within budget. We realize that some added costs may be necessary to achieve certain LEED points, but through a “horse trading” process, we are able to offset some more expensive design assemblies for lesser costly features without reducing the quality of the project; the found savings could then be applied to support the desired sustainable features. The result in both cases was an affordable and sustainable building, achieving the highest LEED certification with no increase above the standard construction budget established for the project.
Even though our owners participated throughout the entire process, at the project’s conclusion, they wanted to know what “premium” was paid for sustainable design. Simply adding up all the costs of a project’s sustainable features a la carte in an attempt to determine the premium is an over-simplification. Individually pricing each sustainable feature is a misleading and inaccurate methodology that does not reflect the complexity of how one sustainable feature can influence the size, quantity or utility of another feature. The best green strategies achieve multiple objectives with a single solution; they are so intertwined that they cannot be separated in a piecemeal manner.
When evaluating the potential costs of the building, it is useful to create a baseline for discussion and balance first cost with long-term benefits using Life Cycle Cost Analysis (LCCA). It is advantageous for the design team and CMAR to evaluate cost options through the cost comparisons of major assemblies. For example, LCCA can identify the best value between a traditional concrete structure versus a steel frame. Similarly, other major systems can be compared: concrete pan joists vs. a concrete flat-plate system; CMU block walls over metal stud framing; or sustainable FSC wood as compared to regular lumber. Cost savings and efficiencies can be determined and integrated into the project scope.
For the RC project, the design team and CMAR collaborated and determined that a 13-inch thick structural concrete “flat slab” floor system provided more advantages than a traditional concrete pan joist system. The CMAR determined that the flat slab system required a shorter construction time, thus reducing the project schedule by three months. This yielded a total savings of nearly $500,000 that was applied toward sustainable design features. The building’s floor-to-floor heights and its overall height were reduced, making the design more compatible with adjacent campus buildings. Twelve hundred linear feet of the entire exterior wall assembly?consisting of exterior brick, metal studs, sheathing, water proofing, insulation and finish drywall?was reduced, representing a real cost savings that was applied to sustainable design features. The flat plate concrete slab also offered a continuous surface, free of beams and joists, which allowed for an efficient and less expensive layout of the mechanical and electrical systems. Accommodating straighter ductwork, fewer elbows and bends, and more direct supply and return ducts resulted in smaller fan sizes and smaller air handler units, providing even further savings in support of sustainable elements.
Exceptional preparation and planning by the project teams helped to maintain quality and budget. In addition to using three-dimensional digital models, the contractor implemented computer software to create a pre-construction quality plan. Through an extensive value assessment and comparison process, the design and construction teams worked together diligently to reduce the project cost by $1 million. By identifying a list of alternative systems, materials, and products, the team allowed the client to build the project affordably without jeopardizing the sustainable design principles, or restricting quality design or functionality.
The UTD building’s most notable characteristic is its management of light with a system of “floating” terra-cotta louvers on the building’s exterior. The design incorporates a shading strategy to provide unique energy efficient protection of the building’s glazed skin reducing radiant heat gain. This allowed the number of air handler units to be reduced in half, thus balancing the cost of the louvers. The louver system allowed for natural daylighting in 76 percent of all spaces and afforded 93 percent of all occupied spaces to have views to the outside. Daylight harvesting?both passive and technological?is achieved with a ‘light scoop’ to funnel natural sunlight deep into a glazed atrium and electronic light sensors are employed to reduce energy loads. The overall design is 63 percent more energy efficient than the average of all buildings on campus.
It is generally considered common knowledge that applying sustainable design strategies to a university building will prove less expensive in the end through operational efficiencies and savings. Making smart choices early in the design process, looking for ways to counterbalance sustainable cost premiums against potential construction savings, seeking trade-offs that balance budget and sustainable goals, and maintaining constant vigilance on cost estimating for a project’s duration, can lead to sustainable and financial success within a university’s first cost budget.
Architect Richard M. Miller is a principal and higher education market sector leader in the Dallas office of Perkins+Will, www.PerkinsWill.com.