A Great Pairing

If it seems as if every time you turn around someone is talking about sustainability, whether it be national news, local news, a neighbor, or your kids, you’re right. Sustainability is becoming part of our vernacular. To put it in perspective, a study of 45 major regional newspapers, collectively cited the term “LEED®” the set of sustainability metrics put forward by the U.S. Green Building Council (USGBC), in just four news stories in 2000. Today, that same group of newspapers is publishing a LEED story at an astonishing rate of nearly one per day - nearly a 100-fold increase since the start of this decade.

Sustainability is, however, much more than the “flavor of the month.” Future generations deserve to live in a world that is in the same condition, if not better, than it is today. Without question, the impact of decisions made today pertaining to the erection of new structures and the modification of existing structures will be felt for decades to come. It is for this reason that all those engaged in building the fabric for future generations must become true stewards of environmental responsibility.

With this is mind, design-build is perhaps the best-suited delivery method to minimize the adverse environmental impact of any project. Each member of the project team has unique knowledge of alternative sustainable strategies as well as the corresponding relationship with other elements of the program. Engaging all parties early in a collaborative manner maximizes the likelihood that the best strategies emerge and that execution closely follows strategic intent.

Not surprising, some of the most successful sustainable construction projects have used the design-build delivery method. In fact, a recent internal study of construction projects conducted by Mortenson Construction suggests that design-build is more likely to be chosen as the preferred delivery method for projects with sustainable objectives than for those projects in which sustainable issues were not considered.

Sustainability Taking Root

The movement toward sustainable construction is taking strong root in private industry. PriceWaterhouse Coopers (PWC), one of the big four accountancy firms, proclaims that sustainability has now “reached the tipping point,” citing a 2006 global survey of their clients in which 70 percent of chief executives of mid-sized to large companies believe that sustainable strategies are directly linked to their profitability and two-thirds believe such strategies will remain a high priority in the future.

The role of third-party watchdogs is only adding to the momentum. SustainAbility, a consultancy that advises on risks and opportunities associated with sustainable development, together with Standard and Poor’s, reports on the quality of corporate sustainability reporting. Such recognizable names as Nike, Ford, General Electric, Gap, and Sony are leading the way.

Even companies not making the rankings are demonstrating their commitment. Citigroup, for example, reports annually on its own energy consumption and its own CO2 emissions, both on a per-square foot basis. Citigroup actually goes so far as to measure the carbon footprint of many projects they finance (see discussion on carbon footprint later in this article). As testimony to this growing trend on transparency in reporting in the private sector, more than half of the companies listed in the top 50 in SustainAbility’s latest survey are newcomers to the biannual ranking.

Financial Sensibility

One stumbling block identified by the PWC study is that many chief financial officers (CFOs) are reportedly reluctant to accept the financial implications of embracing sustainable principles in construction. Some, though, are more progressive. Pepsi’s senior vice president for finance, for example, screens all capital investments in excess of $10 million for three factors: environment, social, and financial results, calling it a “triple bottom line.” But for those owners that don’t have sophisticated in-house assessment tools, leading-edge project teams can point the way.

It is true that many sustainable construction strategies add to the project cost, especially when project cost is viewed solely from within the time horizon provided by design and construction alone. But that’s not always the case, particularly when progressive design-build teams are engaged.

First, consider the alternative. Projects delivered in a traditional manner - design-bid-build, construction manager at risk - thrust builders into a reactive position, responding to prescriptive sustainable strategies put forward by the design team. Further, the design team is placed in a position to design in a vacuum, without input from the supply chain. Often an iterative trial and error process ensues as the designers prescribe sustainable strategies and the builder responds with how those strategies will impact the constructability, costs, and schedule. If the results of these strategies don’t align with the project’s goals (whether they be programmatic, chronologic, or financial) then the design team regroups and delivers a new set of potential ideas. This process unnecessarily consumes project resources, causes delays, and results in uncertain budget feedback to owners - hardly a comforting experience for an already skeptical CFO.

By involving the builder early, alternative materials and sourcing strategies can be evaluated before they are proposed for inclusion in the program. For example, a recent post-project assessment revealed a significant missed opportunity because the construction team was not involved early. In that particular instance, stone was sourced from a remote location when a comparable stone could have been sourced locally. The result was unnecessary emission of greenhouse gases due to unnecessary transportation — not to mention unnecessary project expense.

Fortunately, sustainable construction materials that do become part of the design are becoming increasingly cost-effective because of the growing demand for it. Many sustainable materials are becoming standard, rather than custom, thereby lowering the cost. But often there remains a gap. The emerging notion of lifecycle analysis (LCA) offers promise to lessen the gap.

LCA demands that project teams look at material selection, not just in terms of procurement cost but all environmental costs “cradle to grave” or further still “cradle to cradle.” In this manner, design-build teams can compare a more holistic view of environmental performance of products, offering the opportunity for the owner to select the least burdensome alternative. And with this longer term view, comes the possibility that benefits emerge downstream to offset higher upfront costs.

LCA components include factoring in raw material production, manufacture, distribution, use, and disposal including all intervening transportation steps.

The Essential Ingredient

Collaborative design-build project teams are uniquely positioned to deliver a broader set of cost effective sustainable strategies. By engaging the builder early, the builder becomes a more proactive asset to the project team. Accordingly, the evaluation of alternatives are considered fully in the context of all project filters: programmatic requirements, constructability, economic viability, and sustainability. The result is faster decision-making and more environmentally friendly outcomes.

A project recently completed in Denver, Colo., typifies sustainable design-build at its best. Mortenson Construction was the design-builder for Taxi 2, a 107,000 square foot mixed-use complex located in downtown Denver’s River North neighborhood. Taxi 2 gets its name from its history, in which the site previously served as a parking depot for taxis. The owner and prominent design architects David Baker, Will Bruder, Harry Teague, and Alan Brown rounded out the design-build project team.

The team environment that existed from the project’s inception enabled the successful integration of several sustainable strategies. All the asphalt from the existing parking lot was removed and recycled as backfill material on the same project. The team contemplated medium-density fiberboard for the finish material but replaced it with Wheatsheet, a similar material made of recycled wheat straw rather than wood byproduct, and it was processed using an emission-free binder. The new parking area featured porous landscape detention to lessen storm water runoff and a detention pond to improve storm water quality.

In the Northwest, collaboration on a research building at the University of Washington resulted in recycling of more than 90 percent of construction waste; and 23 percent of new materials were recycled. The team reduced energy consumption by 28 percent through heat recovery insulation materials and lighting control systems. They also reduced water consumption by 38 percent through low-flow water and careful selection of showerheads. Sometimes, as was the case with this particular project, the ambition of the team can lead to positive environmental considerations for related opportunities. Here, the project team engaged the university and brainstormed on sustainability goals ranging from carpooling to the use of alternative fuel vehicles and the creation of a site disturbance master plan.

Preliminary Input

As a deep supply chain produces the equipment and materials that compose buildings, many sustainable design strategies are based on assumptions that businesses within that chain are environmentally responsible and maintain the sustainable character of those products or pieces of equipment. Design-build allows the owner, design team, and builder to create a more complete sustainability picture with a given strategy by facilitating direct input from those providing materials and putting work in place.

Early involvement of craft workers, suppliers, and installers ensures that product specifications are correct and that the builder is buying the proper materials from qualified suppliers. It also ensures that the builder has a plan to coordinate work with any of the desired sustainable strategies. This integration of the owner, designer, and builder is the most effective way to keep the vision of sustainability at the forefront of any discussion related to execution. This, in turn, eliminates surprises and budget problems caused by untested strategies.

Mortenson Construction recently broke ground on a design-build student housing project for the University of Northern Colorado in Greeley, Colo. The owner used the USGBC’s LEED rating system as a guide for measuring project sustainability. As a design-build project, construction and design teams could work together early to ensure that the building envelope and mechanical system were highly efficient. For example, the team was able to increase the thermal resistance of the walls and roof and design a higher efficiency cooling tower. Subcontractors and suppliers were engaged to ensure that these highly efficient systems were also cost-effective. In the end, the building will recognize a 30 percent energy savings as compared to the baseline performance rating per ASHRAE/IESNA Standard 90.1-2004. Because of this energy savings, the owner will receive energy credits from the local utility company.

Waste Stream Forecasting

According to Worldwatch Institute, buildings consume 40 percent, or 3 billion tons, of raw materials globally. The Environmental Protection Agency further estimates that the United States generates 136 million tons of building-related construction and demolition debris in a single year. These are staggering statistics. Properly tracking and managing this waste stream is therefore mission-critical for any sustainable construction project.

Again, the builder’s ability to get engaged early and often as the design is crafted provides an opportunity for waste reduction, reuse, and recycling of items that otherwise flow into the traditional construction waste stream.

For example, with all members of the project team working in collaboration, the design process can incorporate strategies, such as reusing materials on the project itself, reusing materials on a different project, selling materials to an after-market vendor, and implementing a project recycling plan with specific waste management action plans.

The final construction documents can then identify items to be reused and recycled, allowing subcontractors to incorporate this information in original bids and helping to ensure that reused or recycled materials are handled according to plan.

This is occurring on a design-build renovation project for JohnsonDiversey in Sturtevant, Wis. The construction team was brought on early to examine the condition of several items and to determine their suitability for reuse. The integrated team found places to reuse JohnsonDiversey’s doors, light fixtures, electrical panels, glass, frames, casework, and more. This information was added to the design documents, and the waste stream management strategy was integrated into the project.

Modeling Element

The design-build delivery method lends itself well to the use of Building Information Modeling (BIM). BIM allows for the creation of a four-dimensional model that choreographs the building project as it progresses in time. The true benefits of BIM are realized when project data is used throughout both the project design and construction period. Not surprising, design-build teams tend to have very robust BIM collaboration, resulting in a clear depiction, not only of the erection of the facility, but also the corresponding site logistics and schedule considerations.

One very promising avenue for BIM is in the arena of energy modeling. Of course, energy consumption considerations are central to achieving excellence in sustainability. To put the potential in perspective, a publication by the Department of Energy concluded that buildings represent 39 percent of the United States’ primary energy usage and 70 percent of the United States’ electricity consumption.

Architectural Energy Corporation (AEC), a national leader in building energy efficiency services and products based on integrated engineered solutions, uses BIM models for energy modeling. AEC recognizes the benefits of using builders’ BIM models instead of building their own models, especially because it saves time. That said, the software for converting BIM information to models that can be used for this analysis has limitations.

But Michael Holtz, president of AEC, says, “Software companies are working on more seamless ways to link BIM information to modeling software such as energy, daylighting, and air flow.”

Another BIM application pertains to the reduction of site disturbance. Planning and sequencing work in an effort to maximize the efficiency of disturbed construction area can result in less storm water runoff. The builder also can coordinate building systems three dimensionally, using a BIM model, to share model data virtually during the design phase, resulting in an ancillary benefit of reduced project administration paperwork.

On the Horizon

Everyone engaged in construction knows that a building has a footprint. As we turn our attention to its carbon footprint — the total carbon dioxide and other greenhouse gases emitted during the life cycle of a structure — lifecycle analysis (discussed previously) is central to determining that footprint. In the future, look for new standards that define acceptable baselines for various structures. For an amusing, but insightful sneak peek at understanding how to arrive at a carbon footprint, visit www.openthefuture.com, where Jamais Cascio, a noted “futurist,” takes the reader through a step-by-step approach to understanding the carbon footprint associated with the production and consumption of cheeseburgers in the United States.

Companies like Symbiotic Engineering, based in Boulder Colo., are applying the same principles to real applications in construction. The first step toward reducing greenhouse gas emissions is gaining a deeper appreciation for the starting point. Rest assured that progressive design-build teams will be at the forefront of future improvements.