Volume 51, Issue 1 - January 2016


The Pace is Set for Net Zero Energy Buildings

by Nick St. Denis

Increasingly stringent energy codes and the growing momentum of the green building movement are pushing glass and glazing to new heights. Continued development in high-performance, thermally efficient systems is standard practice, while innovative technologies such as dynamic glass provide unique solutions.

The industry is not only keeping up with the demand of high energy efficiency; it’s also adapting to allow developers and designers freedom to use more glass without sacrificing performance.

The countdown to zero is on.

Along with the federal government, state and local leadership bodies throughout the U.S. have set lofty goals to dramatically reduce energy consumption of buildings. The loftiest are those that aim for net zero energy or zero net energy (ZNE) to be the standard in new construction within 15 years.

In collaboration with the National Institute of Building Sciences, the Department of Energy (DOE) has worked with a diverse set of stakeholders in the building industry over the past year to develop a common definition for a zero energy building.

The short answer: “[A]n energy-efficient building where, on a source energy basis, the actual annual delivered energy is less than or equal to the on-site renewable exported energy.”

The shorter answer: A building that produces as much or more energy as it uses.

By that definition, net zero buildings are popping up all over North America. According to the National Buildings Institute (NBI), 39 U.S. states, three provinces and the District of Columbia have ZNE projects within their borders.

Experts in the field—in both the private and public sectors—suspect net zero to be much more than a trend, and with good reason.

Progress Report

The number of ZNE projects in the U.S. doubled from 2012 to 2014, and significant headway was made in 2015, according to NBI. The group tracks buildings in the commercial sector that are either emerging ZNE projects or verified buildings.

Causing a Racquet

Getting to net zero takes a little creativity. That’s exactly what happened at the 435 Indigo Way project in Sunnyvale, Calif.

The now 32,000-square-foot, one-story office building with a 40-percent window area was previously a racquetball court built in the 1970s.

Nearly 2,000 square feet of View electrochromic glass was installed in fixed and operable windows, as well as in the storefront lobby doors. The operable windows were motorized and automated to permit natural ventilation. They self-open and close depending on the weather, putting very little stress on the HVAC system.

“Throughout the day, the weather sensors on the building will detect not only the solar gain but also the ambient temperature,” says View vice president of business development Brandon Tinianov. “Only when the temperature gets too hot does the air conditioning come on. We feel that’s going to be just one total month a year.”

The project was built cost competitively, according to Tinianov. It exceeds California’s stringent Title 24 Energy Code requirements, which call for all new commercial construction to be net zero energy by 2030.

More than 230 net zero projects have been logged as of December 2015. California is by far the biggest user of ZNE buildings, with at least 70 buildings or projects in the state.

Owner-occupied buildings have been the primary adopter of ZNE, largely due to the savings in owner operating costs. The education sector is leading the way thus far, particularly K-12 buildings. NBI CEO Ralph DiNola says that market is ideal for ZNE for many reasons, one being that it’s a “wise use of taxpayers’ resources.”

“Money that goes to paying utility bills doesn’t go to teachers and programs for students,” he says, noting that public schools in California pay approximately a combined $700 million in energy bills. “Imagine if we can get those to ZNE buildings,” he says.

Studies suggest occupant comfort and optimum daylighting affect students’ ability to learn, something that also makes a more “green” solution idea for education.

NBI has participated in workshops and school retrofit pilot projects to show students first hand that buildings can achieve zero net energy. “We’re educating the next generation of leaders and policymakers,” says DiNola.

Where It’s Headed

Office buildings, which also often fall into the owner-occupied category, are a close second in ZNE adoption. DiNola says that’s partly because office buildings are generally “low-energy intensity.”

Additionally, he says NBI is developing an energy code for multifamily buildings and is focused on the California market, as approximately half of the residential construction there is multifamily.

DOE energy technology and policy specialist Cody Taylor says while federal net zero goals exist, the state and local level is “where the rubber meets the road.” Local governments are able to work more with their particular markets.

“You see states and localities contemplating or enacting policies that are tangible,” says Taylor. “States such as California and Massachusetts are putting out goals saying, ‘we want to be this far by this date.’ And they’re backing it up with research.”

DiNola agrees. “Cities compete and states compete,” he says. “They want to lead, and I think this drives the advancement.”

He says many jurisdictions are targeting 2030 as the year when codes are put in place that require all new buildings to be ZNE.

That’s the goal set in California with Title 24; other states such as Washington and Oregon have similar objectives. In fact, a regional organizing group called the Pacific Coast Collaborative—which encompasses Alaska, British Columbia, California, Oregon and Washington—is studying zero net energy goals.

DiNola says New York State is working on a stretch energy code, and Massachusetts has a zero net energy task force. NBI is also working with a ZNE task force in Rhode Island, as well as other local municipalities.

“Cities and states are where the action is,” he says. “It’s great to have federal policy. It’s great to have a vision for the future, but … states and cities have the ability to put these things in place.”

Speaking of Solar

Fabricator J.E. Berkowitz LP also utilizes a solar-panel-covered roof to supplement its energy usage.

While JEB’s facility isn’t operating at net zero, its 7,200 panels on the 180,000-square-foot plant in Pedricktown, N.J., account for approximately 25 percent in savings and significantly cut into the building’s energy usage.

Key Department of Energy Net
Zero/Energy Consumption Goals

• All commercial net zero energy buildings
at low incremental cost by the year 2025

• Net zero energy for all new commercial buildings by 2030

• Zero-energy target for 50 percent of
U.S. commercial buildings by 2040
• Net zero for all U.S. commercial buildings by 2050

Glass Playing a Role

Each building uses its own unique set of characteristics to achieve net zero.

For example, a one- or two-story building that is much wider and longer than it is tall has more roof area for solar panels, and can produce more energy that way. A taller building with the same total square footage has less roof area and must rely on generating energy in other ways, such as solar panels on the façade or more expensive photovoltaic glass.

Ultimately, however, the format is often similar from one project to the next. The building must increase thermal performance, reduce artificial lighting and plug load, and use an efficient HVAC system to get energy use low enough so solar panels can produce the necessary amount of energy.

Glazing is the key.

High-performance fenestration systems, strategic glazing sizes and orientation, operable windows and the use of dynamic glass all contribute directly to energy efficiency.

Taylor says the building envelope is critical because of its lifespan.

“The envelope is the longest-lasting part of any building,” he says. “… Therefore, it’s the part that is worth paying the most careful attention to as far as choices being made at the design and construction levels. If you make good choices, you get the benefits of them for a long time. If you make poor choices, you will suffer the consequences for a long time.”

In terms of glazing, Taylor says new, innovative technologies such as electrochromic and photovoltaic glazing are becoming more important, but the most critical element is simply R-value. “That’s the solid performance baseline we need,” he says.

It’s in the Skin

“The key to cost-effective, zero net energy buildings is the skin.”

That’s the approach Nick Bagatelos of Bagatelos Architectural Glass Systems took in developing a holistic building envelope solution to address net zero.

Bagatelos designed a set of pre-fabricated component system office buildings he says can be delivered at market price and could change the game for suburban office parks across the country.

Stay tuned to USGNN.com™ and USGlassmag.com for the full story this month.

Cost Curve

Perception of cost has been a huge hurdle for the net zero movement.

“The first question that always comes up is, ‘how much more does it cost?’” says DiNola. “But there is evidence that you can design, build and operate a zero net energy building at the same cost of a traditional building.”

Taylor says net zero shouldn’t be thought of as something that’s “tacked on afterward,” but rather treated as a fundamental priority when engaging the design team to deliver on a budget.

“We’ve seen plenty of projects that have done that well,” he says. “They’ve delivered zero energy buildings comparable in cost to other real estate being developed in their market.”

The upfront cost is only the beginning of the equation, however. The purpose of net zero is ultimately to reduce energy costs to nothing, which provides a payback over time to the building owner.

The glass industry doesn’t have to look far for an example.

New Jersey-based fabricator McGrory Glass has 2,782 solar panels on its roof, generating enough electricity—combined with other efficiency measures—to produce net zero consumption of energy.

“It started with the idea that we understood the need for the growing use of electricity use in our business,” says engineering director Jim Gulnick. “We’re continually bringing in new processes, functions and capabilities, as well as redoing old ones to stay up to date technology-wise.”

He says going solar has also made McGrory re-think its approach to purchasing and operating equipment.

“Higher efficiency operations, mini-batch flexible processing, right sizing of capacities, and production optimization are key,” he says. “At the same time we found our need for electrical processes growing, there’s been an international movement in the architectural community to create net zero green buildings. We’re in the industry, and it’s important for us to give back as well as show that we’re committed to the environment long term.”

Those factors, combined with the future return on the investment, made it an easy decision. When assessing the cost of going net zero, Gulnick says it’s a commitment to long-term planning.

“You look at the long-term interest of your own business,” he says. “For us, we’ve been around 30 plus years and plan to be around for many more. … If you’re looking at ‘how much money can I make this year?’ an investment in renewable energy production may not be right for you. If you’re saying ‘I want to be around for the long haul,’ then it makes sense.”

McGrory is on pace for a five- to seven-year payback on its photovoltaic system, and it took advantage of the 30-percent grant the federal government awards to renewable energy generation owners. In addition, the state of New Jersey has additional incentives based on solar energy generation where the company gets paid in the open market by energy generators for every Megawatt hour of renewable energy that the electric utilities do not have to generate themselves.

The company’s move to net zero is an example of how the ZNE conversation his shifted. Much like other developments in the building industry, net zero started as a concept, was nudged along by the design community and now is demanded by the end user.

“The biggest thing that has happened is simply that people have noticed,” says Taylor. “We’ve gone from a handful of design teams out there initiating net zero to a place where we have large owners of buildings who are saying, ‘We should think about adding this to our portfolio.’”

the author
Nick St. Denis is an assistant editor for USGlass magazine. He can be reached at nstdenis@glass.com.

Copyright 2015 Key Communications Inc. All rights reserved.
No reproduction of any type without expressed written permission.