Measuring Green Footprints

In New Orleans pink has become the new green, and Brad Pitt has something to do with it.

As night fell on December 3, 2007, approximately 430 gigantic glowing cubes, lit from within and swaddled in bright pink sheets, appeared along the Lower Ninth Ward. Scattered along the Industrial Canal's shoulder, the cubes resembled plastic pieces on a Monopoly game board. Yet, these are quite literally the building blocks for post-Katrina reconstruction. They represent an equal number of building modules, which, when assembled and installed, will become 150 two-bedroom, single-family homes, each equipped with sustainable components from roof to lower floor. Pitt, the star of Mr. & Mrs. Smith and the Ocean's series, is credited with conceiving the project, dubbed Make It Right (www.makeitrightnola.org).

The majority of the displaced New Orleanians moving into the 940-square-foot "shotgun-style" homes have probably never heard of Green Building Studio (GBS), Revit, or Virtual Environment (VE) software. But they'll feel the impact of these technologies in the warm sunlight, the cool breezes, and even in their pocket books when they pay their utility bill.

Through the use of BIM (Building Information Modeling) and energy analysis software, Berkebile Nelson Immenschuh McDowell (BNIM) Archi­tects, one of the firms involved in the Make It Right project, can determine the optimal structure orientation that makes the best use of the site. For each installation, the architects can foretell with relative certainty the amount of energy that will be generated by the rooftop photovoltaic panels, the volume of rainwater that will flow into the cisterns, and the typical amount of electricity required annually.

In November 1998, the Missouri Department of Natural Resources began brainstorming about a sustainable building. With funding approved in 1999, BNIM began working on the blueprint. The design would include, among other features, the use of daylight and photovoltaic panels to minimize electricity, recycled rainwater to flush toilets, and waterless urinals.

"We tested our theories using four analysis packages: GBS, VE, eQuest (from the Department of Energy), and Ecotech (from Square One Research)," Krygiel says. "We found that because of the sophistication of the design, we're better off using different tools at different stages. Early in the design, we used GBS to get a quick analysis."

GBS's Web-based interface lets architects upload their scheme online and then run a host of energy-efficiency analyses. They then receive a report detailing the building's carbon emission, estimated water use, potential rainwater capture, natural ventilation possibilities, and other green criteria. But for Leadership in Energy and Environmental Design (LEED) certification, for which more robust analyses must be conducted, the architects would use eQuest or VE to fine-tune the design. 

VE offers a series of modules for thermal calculation, carbon check, natural light simulation (based on historical weather data), interior ambience lighting, mechanical components (for studying the operations of ducts, pipes, and electrical cables), and more.

"The original design of the [Lewis and Clark] building was a long, shotgun-style building," recalls Krygiel. "It faced south to get as much natural daylight as possible. We made the building very thin. As we did more analyses, we changed the building to a boomerang shape. That was not only to make it more aesthetically interesting, but also to optimize the amount of light based on the site condition."

The structure's exterior is made of recycled Chicago common bricks and stained cement fiberboard siding. It uses galvanized metal for the gutters, downspouts, front overhangs, and front light fixtures to create a virtually maintenance-free building skin. Two 60-gallon rain barrels fashioned out of recycled plastic connect directly into the downspout flow to collect storm water for indoor use and landscaping. In 2000's currency value, the house's estimated construction cost was a mere $115,000.

Nathan Kipnis, principal of Nathan Kipnis Architects, came up with the project's base home scheme. He expects the occupants to spend approximately $1240 a year on their energy bill-less than $1 per square foot.

Another building scheme that was under consideration in the Green Homes for Chicago program was an advanced version of the constructed Englewood Avenue plan by Kipnis that incorporated passive solar design. 

"We were trying to keep this alternate scheme as inexpensive as possible," Kipnis explains. "We couldn't even afford to use masonry thermal massing. So we used several layers of cement board screwed to the walls, but we had to make sure the sun was actually striking that wall in the winter." Thus, the architectural firm built a 3D model in VectorWorks and then removed a section of the exterior perimeter wall. This allowed the group to see into the model while animating the sun on these particular days, to see where the light would land. 

Kipnis revealed that the estimated annual utility bill for this alternate scheme would have been 30 percent lower than the version that was built, even though it was about 100 square feet larger.

Kipnis is considering adopting GBS. For a Mac-based firm like his, GBS's dual-platform compatible, Web-based environment holds tremendous appeal. At present, he sometimes uses HEED, dual-platform energy analysis software developed by researchers at the University of California, Los Angeles. The program calculates the energy costs and carbon emissions that can be saved with each individual design, remodeling, or maintenance decision made for a home.

"Cougar Community Corner," the Springfield School District newsletter, describes the center as "the first new school building built by the District in 50 years, [housing] all of the District's kindergarten and first graders from Morton and Springfield." In its "Education Doctrine Report" detailing the proj­ect (published in January 2007), Burt Hill representatives recorded the stakeholders' sustainable goals for LEED presentation: indoor air quality, daylighting, a geothermal heating and cooling system to feed the Literacy Center and ETR, and a sustainable design that can also be used as a teaching tool.

Matthew Rooke, an architectural engineer who is a member of Burt Hill's performance analysis team, explains the difficult balancing act required for the center: "The trade-off is, as you increase window areas [to generate daylighting], the energy required to heat or cool those areas increases, as well."

Due to a bank of trees cutting across the site, the building had to be split into two wings that didn't run parallel. The arrangement left the library, the main entrance, and the classrooms on one side, and the kindergarten facilities on the other side.

Texas Hold'Em
Nuevo 2600, a private residence that will be located on a bluff overlooking a lake in Austin, Texas, is currently in development at Webber+Studio. The excavation is scheduled for June 2008, but David Webber, principal of Webber+Studio, knows the layout of the "as yet to be built" home so intimately he can predict the indoor climate of its sections. "I can walk through the plan and tell you that, if I'm in a particular room in June, I'll be very hot, and that there's no way around that but to adjust it with air-conditioning," he says.

Many of these observations are derived from long-tested architectural principles, but Webber has also done quite a bit of computer analyses in conjunction with consultants to back up what his experience reveals. "We did a comprehensive solar study on this house to show how much sun the owner could get," Webber says. The most prominent feature of the Nuevo 2600 site is the slope pointing northwest, "just about the single worst orientation," he adds. Webber's solution was to set the house perpendicular, running counter to the slope.

"We were trying to minimize the facade at that end of the house and its exposure to the harsh sun," says Webber. "Our typical overhangs run from four to six feet-very long-but on that southwestern and northwestern corner, we just have screen walls to break the sun."

Webber cautions, "Use these computer-based analysis programs to check your work, but don't trust them completely."

BNIM's Krygiel agrees: "It's difficult to say that a certain building is performing the way we predicted it would be. If the occupants are leaving the lights on longer or the building is occupied by more people, the energy bill won't be what it's expected to be." Another unpredictable factor is weather. Burt Hill's Rooke points out that changes in weather patterns can also skew analysis results. "We base our [solar energy] models on typical temperatures throughout the year, but one summer might be hotter than another," he says. "Energy prices might fluctuate, as well. And, shoddy construction can lead to poor building performance; this can be something as major as a wall system or as minor as a filter."

Not much can be done about those variables, but architects can take some cautionary measures to prepare their BIM models for optimal analysis results.

"It's important that the architect builds the model with energy analysis in mind," says Rooke. "The energy model's geometry is a simplification of the architectural model. If you're doing analysis, you don't need to know, for example, where the trim on the floor is or where the balustrades are." So conducting energy analysis at an early stage of design, before the architectural embellishments are added, not only enables performance to drive the design, but also saves time.

To this end, IES recently launched VE Toolkits, which are exclusive to Revit users and intended for use at the early concept stages of a project, when only top-level analysis is required. The sustainability Toolkit automatically runs analysis on energy use, carbon emissions, daylighting, and solar performance.

Onuma remarked: "The architectural community is missing the opportunity. We can't think in business terms, as we are undervaluing ourselves. We're limiting ourselves to 6 to 10 percent fees in any construction project while the realtor gets the same for far less work."

The concerns shared by Lucchesi and Onuma are reflected in Lucchesi Galati's workflow, which takes into consideration not only the traditional architectural principles, but also the socioeconomic and business factors.

Lucchesi Galati relies on Graphisoft ArchiCAD, BIM software, for its design work. For building-performance analysis, the company is considering adopting Ecotech, developed by the UK-based Square One Research.

"Ecotech is just one of the many tools we use to simulate building performance, and one of many that we are experimenting with," says Monte Chapin, vice president of Lucchesi Galati. "The other program we're considering is the Onuma Planning System (OPS), a Web-based architectural planning system with XML import tools."

In Onuma's words, "We know everyone is familiar with Excel. So we took Excel and made OPS the conversion tool to allow anyone to do BIM." With OPS, architects might manage a single BIM or thousands of BIMs in an online relational database, link to GIS applications such as Google Earth, and so forth, he adds.

In Chapin's plan for Lucchesi Galati, Ecotech will be a part of the entire portfolio of processes and applications the group will engage to simulate many factors of building performance. "It is more about bringing the aggregate of many separate and distinct applications and perspectives together as a holistic view of simulating building performance, and that whole view is where the cornerstone of ArchiCAD and Onuma's OPS come together, calling on the data that may be available to us using Ecotech," he says.

Products like VE and Ecotech provide feedback on a design's energy footprint in terms of carbon output, energy use, water use, and other parameters. But Lucchesi Galati wants to study what it calls the triple bottom line: the economic, social/cultural, and environmental impacts of its designs. "There are demographics, economic data, and geospatial data relevant to the projects," observes Chapin. "We can bring that data into ArchiCAD, associate them with certain zones in the design, and then do sophisticated analyses. For example, if we know how daylighting affects productivity or learning, now daylight study has a social connection."

Though many of the technologies are available now, putting together the jigsaw puzzle will be the ultimate challenge. "The separate applications, the information, and the data are out there, but the ability to connect them together, to collect, interpret, disseminate, and distribute them collaboratively, is difficult at best right now," says Chapin. "[Lucchesi Galati's] strategic alliance with Kimon Onuma is a small step right now towards that ability. Programs like Ecotech are another important series of steps we have to take to reach out to the future."

Bottom Line
While the list on environmental impact can run long, perhaps the most important parameter to consider in a sustainable architectural project is the client's budget.

"Even the ones with the deepest pockets have a limit as to how much they're willing to spend on a green feature," acknowledges Webber. "In the end, my job is about being a salesman. I need to talk to the client about the importance of investing in sustainability."