Construction Techniques

Diet fads and weight reduction strategies come and go, but the resulting success is always the same — you feel better and are ultimately healthier. Why? Because when you lose weight, your body doesn’t have to work as hard to achieve the same performance results. If you think about it, building designs can also benefit from “diet” strategies that increase performance through reduced energy demands.

Richardsville Elementary, in Bowling Green, Ky., recognized as the nation’s first total energy net-zero public school, was designed utilizing this simple concept. If you are unfamiliar, one of the definitions for net zero is a building that produces the same amount of energy it consumes over the course of a year. Under this definition, any building design can achieve net zero by simply adding enough solar panels or wind turbines to equal the energy consumption. But there is a fundamental flaw to this strategy — alternative energy is still very expensive. If achieving net zero is not coupled with dramatic energy use reduction strategies — i.e. a building “diet” plan — it cannot make financial sense.

So first and foremost, net-zero design is a subtraction or “diet” problem to solve. During the design of Richardsville Elementary, the design team had to rethink every decision, and ask, “How does this strategy affect energy consumption?” It’s important to note that the average school will consume 76 kBtus of energy per square foot per year. Richardsville operates on only 17.5 kBtus.

With a building “diet” strategy, we identified targets for potential energy reduction, such as a high-performance geothermal system, improved building envelope and daylight harvesting. But in terms of a critical path for these decisions, the building envelope kept rising to the top of the list. The strategy would need to be two-fold — design the building to be more compact and choose products/systems that would substantially increase the insulating value/air tightness of the envelope.

Ultimately, we chose insulated concrete forms (ICFs) for the wall system, and increased the R-value of the roof to an R-32 with 6 inches of polyisocyanurate rigid insulation. The Nudura Corporation provided 8-inch and 12-inch ICF forms for the entire wall system (interior and exterior), and we then optimized the system with a simple design that significantly reduced the building’s perimeter wall area. The resulting plan, oriented for proper solar exposure, reduced both construction costs and operating costs with an HVAC system requiring significantly less load. Richardsville cost $197-per-square-foot to build, including the $2.7 million photovoltaics package. By comparison, the Kentucky Department of Education sets the standard cost of construction for a conventional elementary school at $203-per-square-foot, not including any renewables. Other attributes of the ICF system include high wind/storm resistance and increased acoustical isolation.

Additionally, Richardsville took less time to construct with ICFs when compared to conventional load-bearing unit masonry. Today, the top five most energy-efficient schools operating in Kentucky are all constructed with ICFs. 

Kenny Stanfield, AIA, LEED-AP, is a principal in charge the Education Studio at Sherman Carter Barnhart Architects, specializing in the educational planning, programming and design of primary and secondary projects.

The Next Generation 
of Modular Schools
Eight large trucks turned off Los Angeles’ Sunset Boulevard and wound their way through the parking lot behind a vine-covered Spanish-style school. Students cheered as a large crane hoisted rectangular modules, one-by-one onto waiting concrete pads. Hours later, four solar-powered classrooms were generating renewable energy that would help Brentwood School reduce its electricity demands.

What’s most impressive is not that Brentwood’s new classrooms are zero-net-energy, producing as much energy as they consume over the course of a year, but that they are modular ZNE classrooms — L.A.’s first.

“Where only a concrete pad stood that morning, a fully-functional energy-efficient building stood that afternoon,” says Rick Torkelson, director of Operations for Brentwood School. “Premium quality delivered this quickly would have been impossible just a few years ago.”

Modular schools have grown up. Today’s modular classrooms are generations removed from the temporary trailers that were their predecessors. Most modern modulars are permanent construction, built from the same quality materials, with the same 50-year lifecycle, as traditional schools. Some permanent modular buildings go a step further, tapping into the green school movement by offering high performance features once found only in custom site-built schools.

High-performance modulars give school districts the speed and efficiency of prefabricated buildings with the custom look and longevity of conventional construction. Modules are fabricated in a quality-controlled factory at the same time a site-specific concrete foundation is constructed at the school location. The classroom modules are transported to the school, crane-set onto the foundation and finished onsite. From design to delivery, the process can take as little as 60 to 90 days — less than half the build-time of conventional construction. And the savings can be significant.

High performance was top of the agenda for California’s Evergreen Elementary School District (EESD) in spring 2012, when George V. LeyVa Middle School joined the New Tech Network — a progressive network emphasizing a project-based curriculum. EESD knew it would have less than four months to design and build a new high-tech green school and have it student-ready by fall. The aggressive timeline made going modular an easy decision, but not one that required compromises. 

“Timing, cost, quality — all were important,” says Kathy Gomez, EESD superintendent. “But we needed the option of being creative with the space, too. We wanted to build a school-within-a-school, with flexible space that would adapt to our instructional methods.”

What the district really wanted, according to Rob Smiley, EESD’s director of Operations Support Services, was a custom building that could be built affordably over the summer. EESD chose American Modular Systems’ line of classrooms and worked with the Gen7 project team to design-build an oversized, open-concept modular space that allowed students to learn collaboratively and independently in a high performance environment.

It’s not just budget-conscious public schools that are making the switch to modular; private schools are seeing the value, too. The new modular classrooms at L.A.’s Brentwood School are ultra green, engineered to reduce energy consumption by 70 percent before the addition of photovoltaic (PV) panels, freeing up funds for school programs, salaries and supplies.

The ability to cherry-pick features, add sustainable elements and customize interior and exterior finishes allow modular schools to be architecturally unique. A modular classroom wing can be integrated seamlessly into a conventional building or a new modular building can match the aesthetic of an existing campus. To the average observer, modular and traditional construction is often indistinguishable.

But it’s the modern amenities that made the building the right choice for Brentwood School. A natural ventilation system circulates 100-percent fresh, filtered air with the simple push of a button, while low-emitting building material, coupled with continuous air quality monitoring, provides a healthy indoor learning environment. Automatic sensors optimize light and climate-control. Premium acoustics make it 50-percent quieter than the average classroom. An airtight building envelope, natural daylighting and solar panels make Brentwood’s new wing of classrooms a model of energy efficiency and an ideal place to learn.

Brentwood’s modular classrooms were designed to pursue LEED Gold certification. In 10 months, they have generated 17.7 megawatts of electricity — enough to power a football stadium for a day — with carbon offsets of 12.2 tons, the equivalent of an acre of trees.

Modular manufacturers have become visionaries, developing sustainable technology that fulfills emerging needs and finding new ways to streamline production for greater efficiencies and environmental responsibility.

Greening modular schools is where the future is going. California’s Collaborative for High Performance Schools recently expanded its CHPS Verified program to provide a certification for high performance modular classrooms. Over the summer, CHPS and Gen7 introduced the first CHPS PreFAB classroom, a precertified prefabricated model that allows school districts to purchase classrooms clearly designated to meet high performance standards. Making it easy for school districts to green their schools attracts early adopters, inspiring other districts to follow suit.

“The model ensures that more classrooms and schools are high performance and that more students have the opportunity to realize the benefits of attending a healthy, high-performance green school,“ says Bill Orr, CHPS executive director.

According to Tony Sarich, VP of Operations for AMS/Gen7 Schools, “Modular manufacturing continues to push the envelope, redefining the industry by presenting a turnkey sustainable solution that can be adapted to almost any application and offering more choices so school districts can make the right choice for their needs and, ultimately, their students.” 

Pamela Acuff is a freelance writer based in Los Angeles, Calif.