More American real estate developers could be poised to enter the era of the net-zero-energy building, industry experts predicted during ULI’s 2018 Spring Meeting in Detroit.
“A lot of work already has been done with net-zero-energy buildings,” said David Kaneda, a managing principal at the Oakland, California–based Integral Group and an expert on building energy efficiency. “We’ve done over 80 zero-energy buildings, from remodeled office space to residential and including medical, museums, manufacturing, and low-income housing. The results are out there for people to see and learn from.”
Jay Sholl, a senior vice president in the San Francisco office of CBRE and a member of the firm’s Global Corporate Services Group, moderated the discussion, noting that as building codes become more stringent and energy efficiency and renewable technologies become more cost-effective, developers are beginning to aim for net-zero energy in new construction and major renovation projects.
Kaneda stressed that, unlike the scheduling for other projects, the team for a net-zero-energy building should start working together from day one. “It’s pretty simple to design buildings like this,” he continued. “But the team must work together from the start. Architects sometimes don’t talk to the engineers until later, but with a net-zero-energy building, engineering affects the building design from the very beginning and everyone should be involved.”
According to the U.S. Department of Energy, a net-zero-energy building produces enough renewable energy to meet its own annual energy consumption requirements, thus reducing the use of nonrenewable energy. Net-zero structures use cost-effective measures to reduce energy use through efficiency and include renewable-energy systems that produce enough energy to meet remaining needs. The advantages of net-zero buildings include lower environmental impacts, lower operating and maintenance costs, better resilience to power outages and natural disasters, and improved energy security.
For a net-zero-energy structure, setting an energy-use goal at the onset is critical as is continuing modeling, Kaneda said. He added:
- The choice of building skin is critical to letting heat in or keeping heat out.
- Natural light should be used whenever possible.
- Efficient HVAC systems are critical. “A lot of time, you can use off-the-shelf standard technology in creative ways to get efficiencies,” he added.
- The effect of “plug-in equipment,” such as laptops, copiers, printers, and microwaves, should be determined. “We found that, in a lot of cases, when we measure energy use of buildings, plug-in equipment is more than half the energy,” he said.
Yolanda Cole, senior principal and owner of Hickok Cole Architects, a large commercial architecture and interiors firm in Washington, D.C., noted that a vast majority of net-zero buildings have been completed in sunny California, where the climate is hospitable, and the projects have sufficient space. However, Hickok Cole Architects undertook the net-zero-energy renovation of the American Geophysical Union (AGU) in the historic neighborhood of Dupont Circle in Washington, D.C. “It was a retrofit of a 65,000-square-foot [6,000 sq m] building that was coming to the end of its useful life,” she explains. “The AGU wanted to change the way they worked and become a role model and catalyst for others.”
Working closely with the engineering, contracting, and AGU teams, Hickok Cole decided to use a municipal sewer heat exchange system to recover thermal energy from wastewater. Beneath the street near the building was a large combined storm and sanitary sewer line built in the 1890s. The municipal sewer heat exchange system will tap into the sewer line and divert wastewater to a settling tank outside the building, she told attendees. Water from the settling tank will then be circulated inside the building to an exchange system that will extract energy from the water for heating and cooling before the water is returned to the sanitary sewer system.
Read more: https://urbanland.uli.org/sustainability/net-zero-energy-construction-becoming-cost-effective/