Green Roof Provides Learning Opportunities at the University of Iowa’s Pappajohn Biomedical Discovery Building

Established just 59 days after Iowa became a state in 1847, the University of Iowa, Iowa City, boasts a number of firsts. In 1855, it became the first U.S. public university to admit men and women; at that time, its enrollment consisted of 124 students—41 of which were women. In 1873, it was the first school to grant a law degree to a woman. In 1895, it became the first university to place an African American on a varsity sports team.

As such, the university’s new Pappajohn Biomedical Discovery Building was designed and built with sustainability in mind. PHOTO: Roof Top Sedums LLC

The university’s new Pappajohn Biomedical Discovery Building was designed and built with sustainability in mind. PHOTO: Roof Top Sedums LLC


In more recent years, the university has strived to lead via its environmental efforts. As a Green Power Partner of the Washington, D.C.-based U.S. Environmental Protection Agency, the university pledges to reduce the environmental impact of electricity generation through the use of renewables. In 2010, it established its first sustainability plan—2020 Vision UIowa Sustainability Targets, which contains the following goals:

  • Become a Net-negative Energy Consumer
  • Green Our Energy Portfolio
  • Decrease Our Production of Waste
  • Reduce the Carbon Impact of Transportation
  • Increase Student Opportunities to Learn and Practice Principles of Sustainability
  • Support and Grow Interdisciplinary Research in Sustainability-focused and Related Areas
  • Develop Partnerships and Advance Collaborative Initiatives, both Academic and Operational

Among the University of Iowa’s strategies to achieve its sustainability goals is ensuring all new construction and major renovations on campus achieve a minimum LEED Silver certification from the U.S. Green Building Council, Washington.

The 200,000-square-foot, 6-story building, which officially opened in October 2014, boasts many environmentally friendly attributes.

The 200,000-square-foot, 6-story building, which officially opened in October 2014, boasts many environmentally friendly attributes. PHOTO: Scott Nagel


As such, the university’s new Pappajohn Biomedical Discovery Building was designed and built with sustainability in mind. The 200,000-square-foot, 6-story building, which officially opened in October 2014, boasts many environmentally friendly attributes, including glow-emitting sealants, paints, carpet and other materials; water-efficient landscaping; and recycled content and regional materials. It also achieves an-other university first: three green roofs, one of which provides students the opportunity to grow medicinal plants.

Opting for Trays

Des Moines, Iowa-based landscape architecture firm Confluence has been completing projects at the University of Iowa for many years through its Iowa offices—Des Moines and Cedar Rapids. Confluence was hired by the project’s architect of record, Rohrbach Associates PC Architects, Iowa City, to complete landscaping around and on top of the Pappajohn Biomedical Discovery Building in the form of three green roofs that total approximately 6,440 square feet. Despite the building’s consider-able roof area, the design team opted to install the green roofs on lower roof areas upon which building occupants would be looking. The rest of the roof cover is a reflective membrane system.

Confluence provided the layout for a modular green roof on the three distinctive roof areas. Patrick Alvord, PLA, RA, LEED AP, a principal in Confluence’s Cedar Rapids office, notes the chosen tray system was off-the-rack, which is what made it appealing to him and his colleagues. “We spent a lot of time talking to the manufacturer and they were just great to work with,” Alvord says. “We had a number of case studies of work they had done in the Chicagoland area that had proven very successful, so we had a very high level of comfort right out of the gate.”

Alvord opted to use the 6-inch-deep tray model because it would provide some flexibility in the plant materials that could be specified. “We were able to specify different plant materials in the plan of the roof to coordinate with shade, densities and location,” he says. “In areas where the roof would be highly visible from floors above, we did some patterning with the plants. In areas where we had the opportunity to go deep, we planted deeper-rooting plants that will grow taller and provide a denser plant palette.”

The plants are a mix of native and adaptive Iowa plants, as well as recommendations from the green-roof supplier. “It’s a mix of perennials, grasses and forbs, ranging from sedums to liatris to a number of different things,” Alvord notes.

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Redefining Sustainability

My company is currently in the process of restoring more than 1,600 window sashes for a large historic project in Buffalo, N.Y. As I recently walked through our plant and saw the thousands of windows in various stages of repair, I reflected upon how we were repairing windows that are more than 135-years old. This made me think about the current state of the construction industry and what our expectations are for the life of a building structure and the components that make up that structure. During the past 10 years, there has been a great deal of talk about green buildings and sustainability, but how many of these “green” commercial or residential buildings are designed or constructed to last for centuries? When will the life cycle of the structure and the construction materials themselves become factors in the sustainability criteria? It seems to me that more effort is placed on whether a material is recyclable than whether it can perform over the long haul. It is time that the design community, manufacturers and construction processes begin to consider the life of the building if we are truly going to incorporate sustainability in our industry.

Back in 1993, the U.S. Green Building Council developed the LEED green building rating system as a way to guide building owners to be environmentally accountable and to use resources responsibly. The LEED system has had a profound effect upon the design community by motivating advancements in energy efficiency, use of recyclable materials, incorporation of natural daylight and reuse of water. The LEED program made the word “sustainability” a household term over the past ten years, but has it truly redefined sustainable design? I would submit that LEED has been most successful in motivating changes in how structures consume natural resources and how the structure can be recycled at the end of its useful life. Very little emphasis has been put on designing a structure and using component materials that will last for many generations.

I like the definition of sustainability from author and professor Geir B. Asheim. “Sustainability is defined as a requirement of our generation to manage the resource base such that the average quality of life that we ensure ourselves can potentially be shared by all future generations.” I would submit that true sustainability in the construction industry implies that we construct edifices that can be used for many generations. It does not mean that we build a structure that has to have its major components replaced every 20 years.

Take windows for example. The major window manufacturers have developed designs that require the replacement of the entire window once the insulated glass seal has failed. Although the window is made of materials that can be recycled, it isn’t designed for multi-generational, long-term use. Changes in the glazing details that would facilitate glass replacement could dramatically extend the lifespan of these products. Other manufacturers use inexpensive materials such as vinyl for major structural members that have spurious life expectancy. Ask any window manufacturer for the life expectancy of their products and they will refer to their 10 year product and 20 year glass warranties. Is it unreasonable to expect a window to last for more than 20 years? I don’t think so.

Other products such as appliances, finishes, roofing, HVAC, lighting, siding, etc. also have very limited life expectancies. Some promote lifetime warranties that are so burdened with legalese they are rendered useless. By limiting the warranty to the original purchaser, prorating the warranty every year, and limiting exposure, the warranty actually protects the manufacturer more than the purchaser. American manufacturers have become more concerned with cutting costs than building better products. If manufacturers made changes in designs and the base materials used in fabrication, they could dramatically improve the expected years of service. Although many of the changes in materials will increase prices, there is a market for more durable products.

It’s time that the construction industry begins to take the life cycle of our new structures more seriously. We need to make advances in the quality of our construction designs and materials for the industry to truly become driven by sustainability. We should view our work as a testament for future generations rather than a disposable structure that will eventually be long forgotten.

This blog post first appeared on Re-View’s Window Review Blog.

GAF Sponsors Certified Green Distributor Program

GAF is sponsoring the new Certified Green Distributor Program, an extension of the highly successful Certified Green Dealer Program. The Certified Green Distributor Program now offers online, on-demand training, green certification and marketing support to the nation’s one-step distributors.

The training is web-based and covers five topics that are central to one-step distributors: Air Sealing, Cladding, Roofing, Insulation, and Roof Shingle Recycling. Each course module is accompanied by a downloadable study guide.

GAF’s sponsorship is just one of the many steps that the company has taken to support green-building training and roof recycling initiatives. In addition to sponsoring the Certified Green Distributor Program, GAF has instituted highly regarded internal sustainability efforts. GAF has also launched the Certified Green Roofer Program, which includes a multiyear sponsorship of ShingleRecycling.org, a site that helps contractors and distributors connect with qualified shingle recyclers across the U.S. and Canada. Its dedicated webpage for green building, offers a wide range of related resources, including tools and information to educate and inform roofers and contractors about the importance of cool roofs, roof ventilation, and green codes and rating systems.

Green-building Innovation Is Important, But So Is Refinement

In March 2006, I swore allegiance to the wildly popular green-building movement. I even put the kibosh on my favorite joke about recycling in the landfill—you know, so not to deprive future generations of fossil fuels and diamonds. Nice.

I’ve worked in facility management at Duke University Health System for 26 years. In this profession, being overly pragmatic is an occupational hazard. So, why did an “old-school” guy (no pun intended) show up at a green love fest alongside folk with funny-colored hair and way too many bumper stickers? Quite simply, I came to the party to plea for intellectual honesty.

Unfortunately, early on, the sustainability movement offered myriad earth-friendly materials often with little thought to their durability or life cycle. Similarly, early building rating programs focused largely on the merits of individual products without factoring their proper integration into functional systems or assemblies. Consider, for example, the many thousands of squares of reflective “cool roofing” membranes applied over non-durable assemblies. A LEED-applicable roofing membrane that fails prematurely because of inferior quality or misapplication does not look very sustainable buried in a landfill.

It’s no longer 2006, and the greenie you’re partying with may be a blue-haired, retired architect. It’s encouraging so many in the building industry, and particularly the roofing industry, have embraced the concept of durability as the essence of green and sustainable building design. Moving beyond mere branding “strategery,” sustainability can be good for the bottom line. On the Duke campus, a 2007 roof replacement used forward-thinking design to divert 718 tons of solid waste. Salvaged materials from this effort included 296,000 board feet of XPS insulation, which was repurposed in new roofing construction on three Duke buildings. It’s our story. And it’s simply good business.

It has been said “architecture is storytelling.” The story of our 2007 roof replacement project settled forever how Duke University Health System will conduct itself in regard to sustainable roofing design and environmental stewardship. We distilled our story into the following “Guiding Principles of Sustainable Roofing”:

  • 1. Favor insulations or insulating assemblies that are highly resistant to water and physical damage.
  • 2. Favor roof assemblies that position the roof membrane directly over a permanent or semi-permanent substrate.
  • 3. Favor roof designs that prohibit or highly discourage the entrapment of water within the roof assembly.
  • 4. Favor membrane and insulation designs capable of in-place reuse or recycle in future roof iterations.

Through the years, these guiding principles have produced a dramatic improvement in roofing performance on our campus. In particular, our emphasis on adaptive reuse of materials will minimize our impact on the environment, as well as reduce future demand on hospital resources–resources best used in support of outstanding patient care or cancer research, not funding a premature roof replacement. Interestingly, the U.S. General Services Administration, Washington, D.C., has recently incorporated our guiding principles in facilities standards for future public building construction. Now our story has legs.

In April 2013, I attended the Energy Efficient Roofing Conference in Charlotte. I was invited to participate in the program, offering a building owner’s perspective about emerging roofing technologies. The focus, primarily, was energy-efficient roofing as a value proposition: how to achieve it and how to sell it. The format leaned heavily on panel discussions, which produced large amounts of banter and at times outright tension regarding the subjects at hand. It was as if someone handed a microphone to the elephant in the room. Has the proposition become a “solution” in search of a “problem”?

Don’t misunderstand; everyone can see the benefits in much (but not all) of the new energy-efficient roofing innovations and building codes. But should we be excited about reflective or solar membranes on massively thick R-30 minimum insulation while still far too many roof installations will fail prematurely because of shortsighted design and construction? If quality and durability are of utmost value, do you—the roofing contractor— know how to achieve it and how to sell it? Should you care?

Back in 2006, I believed everyone was trying to “out green” each other; durability be damned. Today, I wonder if the problem is that everyone wants to “out innovate” each other. As we’ve witnessed with green, the danger when innovation means everything is that it can soon mean nothing.

Innovation is exciting and necessary, but so is refinement. Refinement may be the most powerful strategy of all, yet it remains under emphasized. The most effective way to celebrate refinement is by creating new stories–new institutional memories. Roofing contractor, you are the biographer. Run with that.