Scaling to zero


Building mechanical teams play an important role in the transformation toward zero-energy buildings

A future of zero-energy building: Is it possible?

Cities across North America are creating zero-energy initiatives to promote energy efficiency and lower greenhouse gas emissions. Buildings play an important role in helping cities achieve these ambitious goals, as they are a prominent source of greenhouse gas emissions. For example, in Washington DC, buildings account for 75% of emissions within the city, with other sources such as transportation and waste contributing significantly smaller emissions percentages.* 

The zero-energy plans put in place by cities heavily focus on constructing new buildings with energy-efficient systems and retrofitting older, inefficient buildings. While achieving zero-energy may seem like a stretch goal for ambitious builders, it relies on technology that is readily available. Here’s what sustainable building experts have to say about moving toward a zero-energy future.

Start with mechanical system design 

A sustainable building starts with the design of its mechanical systems. Cindy Cogil, principal and director of engineering at SmithGroup, offers advice on where to begin zero-energy building design.

“You can’t manage what you don’t measure,” Cogil explains. “So, I think there are some really important first steps for any sustainable building project, starting with energy benchmarking, climate analysis and shoebox modeling. These steps will help you understand your energy use and where to target. Before any kind of detailed analysis can be performed, it’s really important to understand the data input parameters.” 

Electrify the built environment 

Electrification is growing in popularity across North America.  These all-electric buildings strive to have no fossil fuel burning equipment on site. 

Adrienne Johnson, associate engineer at Point Energy Innovations, resides in California where electrification is especially prominent. The California electrical grid is more than a third renewable, which pairs well with all-electric buildings. “When we talk about electrification, we’re talking about switching our space, water heating and cooking technology from fossil fuel combustion options to all-electric in order to take advantage of our increasingly renewable electricity sources,” Johnson explains. “Electrification of our buildings is actually becoming a much more critical, and in many ways attainable, standard over zero-net energy on site. Pretty much 100% of our projects are electric. We're finding that the mechanical contractors we work with are a lot more familiar with the systems, which leads to lower risk for them. And in turn, owners get better pricing for these options, which is really going to be a requirement for this trend to continue.”

Increase the visibility of building energy use

Building energy usage has become easily accessible over the years, sparking conversations about how much visibility should be given to occupants. Cathy Higgins, research director at New Buildings Institute, advocates energy transparency.  

“Energy needs to be transparent for awareness,” Higgins says. “Building energy usage has been behind the scenes for a long time, so we need to raise awareness of the relationship between the design, the building systems and the occupant and operator roles. It’s critical that we raise awareness of the relationship between our actions and energy use, and how that is connected to what we use to fuel our buildings and our greater environment.”

Rise above the challenges

If you’re working with clients who don’t have zero-energy buildings in mind, there are several ways you can encourage them. Johnson provides a framework for conversations about getting others on board with sustainable buildings: 

  1. Ask about the health and comfort outcomes for future occupants of high-performance buildings. People gravitate toward green buildings, which are leased faster than standard buildings. Questions about the occupant experience makes zero-energy more tangible for the owner. 
  2. Remind clients that there are different versions of net-zero that can reduce carbon emissions. Net-zero carbon allows you to design all-electric, low-energy buildings with some PVs on site, while procuring the rest of the power from renewable resources. 
  3. If your customer has no interest in zero-energy, you can write into your basis of design the lowest energy use systems. You can at least push to have a low-energy building even if you can’t get it all the way to zero. We can still move the needle quite a lot and influence the way that the client will think about their next building. 

Understand it’s a journey

Getting buildings to zero is a process that won’t happen overnight, but don’t let that discourage you. “Energy is different every minute that your meter is running,” says Higgins. “You may or may not be zero at any given time. You may never even actually get to zero, which is a measurement of an annual basis. Please be proud of really good design and low energy use. That's why we call it getting to zero. It's a journey. Let's just try to get buildings to have the lowest possible environmental impact through reduced energy use while being really effective and beautiful designs.”

To learn more about a zero-energy future, watch our “Scaling to Zero” online seminar

For some energy-efficient projects that REHAU customers have contributed to, visit: www.na.rehau.com/netzero

By Erin Slupe, REHAU Communications


*Source: https://carbonneutralcities.org/
 

Engineering progress

Enhancing lives