In June, ULI hosted a webinar on electrification as part of its Net Zero series, the third installment in the series is part of ULI’s ongoing effort to foster discussion around how to achieve net zero emissions.
One part of what makes these webinars so special is that they are not truly webinars as we think of them in the traditional sense, rather they are discussions where all attendees can share thoughts and best practices participants have learned on their journey to net zero.
As per ULI, net zero refers to a building or portfolio of buildings that is highly efficient and powered by renewable resources and offsets. Currently, buildings are responsible for 40 percent of global greenhouse emissions, a figure that increases to up to 70 percent in major metropolitan areas. ULI approaches the journey to net zero via several “buckets,” one of which is electrification.
Speakers Stet Sanborn, engineering discipline leader, SmithGroup; and Sara Neff, head of ESG, LendLease Americas, walked attendees through some common problems with achieving net zero through electrification and offered actionable tips for moving forward to carbon neutrality.
Make the Existing Space Work for Your Needs
Sanborn shared two projects that he recently worked on, the first of which was an all-electric, net-positive retrofit. Something to keep in mind when aiming for net zero in a retrofit project is to put efficiency first.
In this project, Sanborn’s team focused on mixed-mode heating and cooling with ventilation. This meant making sure windows were operational, using the existing concrete to assist with cooling, adding insulation, and improving glazing throughout the building.
Adding ceiling fans was a huge help in keeping the temperature down without using an abundance of energy or incurring too much extra cost. One benefit of ceiling fans is it gives the occupants more control over the indoor temperature and allows the setpoint of the cooling element to be set lower, as ceiling fans tend to lower the indoor temperature by about three degrees.
While that might not seem like a lot, Sanborn notes it saves about 20 percent of energy and can lead to a summertime cost savings of about 30 percent or higher. Ceiling fans can also reduce the amount of ductwork needed in a building by helping to move the air through the space, mitigating the cost of other improvements you may want to implement.
Additionally, Sanborn used an existing storage area under the parking facility (which was not at full height and similar to a basement) to create a “thermal labyrinth.” What this space does is pre-cool the air using the ground temperature so that in the summertime, the air that enters the building is between three and 14 degrees cooler than the outside air temperature.
Tubular daylighting helps reduce the energy needed to light a space during daylight hours. All of these strategies can help a building be more efficient. Sanborn advises, “Find out all the things your building can do before you put fancy tech into buildings.”
Historical Buildings Present a Challenge but It’s Not Insurmountable
When electrifying a historic building, Sanborn says the challenges can include the amount of space, the budgetary constraints, and whether a building is registered as a historical landmark. He recently worked on one project that included all of these challenges and shared some of the lessons he learned.
It’s crucial to gather data before proceeding with a project. He says, “I don’t want to decarbonize anything that I haven’t seen actual loads for, because there’s lots of nuance in the loads that can help you find ways to save money.” For this project—which involved decarbonization of the heating system—that was heating load data.
With the data of heating loads versus local weather data, it is easier to see how efficient a system will be once it is in place. You can measure different technologies against the existing systems in a building, the local electrical grid, and more to really paint a picture of how everything will work.
The building was a church, which has its highest heating needs once a week for Sunday service. Rather than buy a heat pump that would only be needed for an hour or so once weekly and then be operating at 50 percent the rest of the time, Sanborn added a thermal energy storage tank to cover the peak, which allowed the heat pump to be 40 percent smaller.
“The whole goal of electrification is actually to save emissions. If I electrify a building and end up with more emissions, I have not done a good job. So, efficiency first, and then actually doing the math to check on those emissions profiles,” Sanborn explains.
Looking at Electrification Holistically
As LendLease works to be at absolute zero by 2040, it is moving away from fuels entirely and has learned lessons along the way. An important thing to remember when spending money to electrify a home is the cost savings you get in other ways, such as not having to pay to connect a gas line.
For a project Neff is working on retrofitting some existing homes, she says decarbonization and fuel switching results in a 30 percent decrease in energy usage in these homes. This translates to the project being cash flow positive from day one, which can be important when looking to get financing.
Neff also notes that while being 100 percent electric is great and is the ultimate goal, it is okay to do a project in smaller pieces that are attainable now with the budget and constraints you are working with. In a multifamily building, this could look like a hybrid system where the apartments themselves are fully electric, but the building’s hot water system is still fueled by gas, which is a system that can be easily swapped out for an electric one at the next phase.
When it comes to electrification, she advises it’s important not to miss the forest for the trees.
