Setting a good example is what governmental and religious institutions are expected to do, and two in Iowa did just that by showcasing just how efficient new buildings can be when following best practices in energy and water management.
Developers of a government building in Des Moines and a skilled nursing facility for elderly nuns in Dubuque presented their case studies at a conference on Oct. 3.
Scott Bowman, an engineer at KJWW Engineering Consultants, and Carey Nagel, an architect with BNIM Architects, told the story behind the new home of the Iowa Utilities Board and the Office of Consumer Advocate, a LEED-Platinum “net zero ready” building they believe serves as a blueprint for construction of other energy-efficient buildings.
In a separate workshop at the fifth annual Growing Sustainable Communities Conference – Midwestern Region in Dubuque, Mark Hanson of Hoffman Planning, Design & Construction, Inc., introduced attendees to the Clare House, a 93,202 square foot infirmary designed to reduce operating costs for the Catholic Sisters of St. Francis while enhancing the care of their elderly and infirmed.
Iowa Utilities Board and Office of Consumer Advocate Office Building
Dedicated in April 2011, the new building on the state capital complex in Des Moines houses more than 90 employees of the two agencies, replacing their former headquarters in what Bowman called “the worst building in Iowa.” The engineering and architecture firms came together with the building’s owners as an integrated team to “innovate, but to use established tools and technology to get extraordinary results,” according to Nagel.
They wanted to develop a building process that was driven by energy efficiency but that could be replicated anywhere. Their “process for high performance” included the collaboration of an integrated team, and a post-occupancy measurement and verification plan.
“This was about creating a process of simple ideas for any budget with any team,” Nagel said.
Their “energy efficiency-driven vision” was to construct a building with a total Energy Utilization Index (EUI) of 28.0 kBTU per square foot, per year. Bowman explained that this number represented a 60 percent reduction from the code base EUI of 72.5 kBTU. After almost a year of operation, the building so far has operated at an average of 21.6 kBTU.
They hadn’t started out planning for LEED-platinum certification, but “the goal of creating a good indoor environment for workers prompted us to go all the way with certification,” which is pending, Bowman said.
The building is 44,640 gross square feet, which is the measurement taken from outside the building walls. The construction cost of the building was $204 per GSF. As part of the integrated design process, stakeholders gathered to discuss their ideas, the most important of which included the envelope, orientation on the lot, incorporation of daylight, natural ventilation, owner vision, client education and plan organization.
As for energy efficiency, the team realized they could use less energy in some situations, use energy more efficiently in others, and even make some of their own renewable energy on site.
“How do you go for higher efficiency in a building?” Bowman asked. “Start by using less. Reduce load. Mechanical systems shouldn’t last more than 25 years because improvements will come along, but the envelope will never be easier to do than now.”
But he added: “For photovoltaic, don’t buy anything until you are ready for it because technology gets better and costs go down” over time. This building’s roof-mounted photovoltaic solar panels provide 13 percent of total energy needs while offsetting loads during peak demand.
In conventional buildings, the largest piece of the energy pie goes for heating, followed by cooling, fans and pumps, lights, plug load and hot water. But in this new building, Bowman said, heating and cooling are much smaller pieces of the pie, while the plug load is the most significant portion.
The building lies on a former fill site, where there had been a coal mine long ago. An east/west orientation allows daylight into the core of the building. The interior is “austere,” with exposed steel and zinc cladding mixed with walnut panels and furnishing.
Bowman joked that he might be “drummed out of engineering” because he keeps “trying to eliminate things engineers like to build.” In this case, the team didn’t want occupants to rely entirely on automated temperature controls. They should be able to open windows – psychologically it makes people feel more comfortable if they have some control over their surroundings, he said. It is also a business issue, because if there is a ventilation failure, at least people can open windows and continue to function, even if in a less comfortable atmosphere. Lest people open windows and forget to shut them overnight, various controls prompt people to open windows when appropriate, while shutting off mechanical systems, and alerting occupants when they are left open at day’s end.
Bowman explained the various policies that control heating and cooling. There is a mandate that heat cannot be used until the air temperature is cooler than 68, and cooling not until it is at least 76. There are also plug load policies. Occupants are not allowed to bring in power strips to plug in their own space heaters or small appliances. This rule got some push-back at first, but eventually occupants started to “have pride in the building and a connection to the outcome,” Bowman said.
The agencies inhabit two wings in the building. The north wing houses the Iowa Utilities Board. The first level of the south wing includes the hearing room for the Utilities Board as well as large conference rooms shared by the two organizations. The second level includes open offices facing south, enclosed space to the north, and glazing on windows to mitigate heat gain and glare. It features daylight harvesting sunscreens with moveable louvers that can be adjusted seasonally.
The exterior is made of cast concrete with banded windows, but as Nagel said, “the harvesting screens became the architecture.” Further, the precast concrete provides a good thermal envelope that prevents air infiltration. The building was constructed of 35 percent recycled material; 66 percent regionally extracted, harvested and fabricated material; and 96 percent of the wood was certified by the Forestry Stewardship Council as “responsibly harvested.” Finally, 89 percent of construction waste was recovered, and 100 percent of the annual rainfall is captured and filtered by six acres of restored prairie on an adjacent lot, which mitigates catastrophic flooding.
While team members were interested in innovation, they also wanted features that could be replicated in any building. All new buildings can be intelligently sited on their lots to take best advantage of daylight and landscaping. They can allow for natural ventilation while still employing a good thermal envelope. Energy use can be monitored in lighting, plug loads, mechanical equipment, general building loads and IT equipment. Monitoring ensures things are operating as intended, helps identify additional savings, and provides research and demonstration data.
“These strategies are scalable for any building,” Nagel said.
Clare House Skilled Nursing Facility
Clare House is an infirmary at the Mount St. Francis convent in Dubuque. It houses 75 full time residents and includes a full kitchen and dining area, a chapel, offices and service facilities. Hanson said the sisters, as members of the Franciscan tradition, live according to a set of values that includes reverence for all living things. That was the code that moved them toward energy efficient and sustainable choices in all their decisions. For their own reasons, Hanson said, the sisters decided not to seek LEED certification for the building. However, he said, the choices they made were consistent with LEED guidelines.
The project started with the architects and the sisters addressing several basic questions that Hanson said should start any construction or renovation project. Does the building meet your functional needs? Does it have the aesthetic appeal you want? Is the project highly sustainable or green? Should you certify green aspects of the project (i.e. third party review)? Do you want to meet conventional cost levels (first costs)? What delivery method will you specify: integrated project delivery or design-bid-build? How will performance be validated?
Hanson believes green building can be done without spending more than with traditional building materials and methods. The Clare House project was delivered at $195 per square foot, which includes design and construction costs. The sisters moved into their space about a year ago.
Hanson said the building is surrounded by water efficient landscaping and drought tolerant plants without permanent irrigation systems. The house is on a hill with little to no conventional grass or lawn. Instead it is mostly native prairie, which is excellent for dealing with drought and storm water. The facility uses minimal paved surfaces and those that are paved are light in color, Hanson said.
A few trees that had to be cleared during construction were chipped into bark mulch, and a prairie restoration was planted over a geothermal well field. The geothermal system at Clare House consists of 111 wells, 300 feet deep. Regionally manufactured windows provide comfort and views, and are glazed to control glare.
The building’s energy-efficiency is monitored, and the results are available to the sisters in an online portal. Hanson said the Clare House saves the convent about $186,000 a year in energy costs.
The sisters are continuing to honor their Franciscan traditions by cleaning with green products and exploring options for generating more renewable energy. Hanson said the house is solar ready, and when the time is right they will install a system. Meanwhile, they have added a humidity system for the comfort of elderly sisters. Caregivers report that the positive changes in their environment seem to make a difference in the comfort and longevity of the sisters receiving skilled care at Clare House.