Retrofitting existing buildings to be environmentally sustainable is one thing, but, for those deemed historically significant, upgrades require a whole other level of problem solving.

More electrical contractors need to be versed in integrating electrical systems in historic buildings, especially older homes, that enhance energy efficiency and achieve decarbonization, said Bonnie McDonald, president and CEO of Landmarks Illinois, a Chicago-based nonprofit specializing in historic preservation.

“This is the future of municipal building, energy and life safety codes,” McDonald said. “Electrical contractors are most knowledgeable about the ways to advance safety, usability and comfort for historic building owners and tenants. Preservationists can be partners in the effort to develop policy solutions that reflect the electrical contracting industry’s expertise.”

Active energy-efficient design solutions for historic buildings either use or produce electricity, and that requires an electrical contractor’s expertise, she said. For example, a building’s roof, secondary structure roofs and yards can house solar panels or shingles, depending on the climate and roof orientation. 

One-of-a-kind buildings

“Proactively promoting solar arrays on historic buildings can dispel the myth that we care more about buildings and aesthetics than the people using them,” McDonald said.

Perhaps the most challenging aspect of working on a historic building is that each one is unique, considering its as-built design changes over time, she said. As such, systematizing a construction approach to operate efficiently can be complicated. An electrical contractor may find several eras of electrification and may have to dismantle or navigate around legacy wiring.

Then there is the challenge of feeding wire through existing walls that may or may not have fire breaks, deteriorating insulation, past repairs and other building systems.

“From time to time, a contractor may find past electrical work not done by a qualified professional—worse yet, a dangerous ‘homeowner special,’” McDonald said. “Buildings may need to be fully rewired, which the building owner may not be able to afford considering other necessary repairs.”

Electrical contractors should invest in training and technology that can help their teams identify and understand legacy electrical systems that may be present in older buildings, she said. Radar and thermal imaging can help map current conditions to better estimate and plan out a project.

“Barring the opportunity to open the existing wall cavity, which can be counterintuitive to saving existing material, there are limited ways to mitigate the complexity of navigating existing conditions,” McDonald said.

Issues to consider

Scott Block, vice president of Block Electric Co. Inc., Niles, Ill., agrees. Block Electric has developed a niche for upgrading or replacing lighting in historic buildings, as well as installing lighting controls, new power outlets, new fire alarm systems and low-voltage systems such as voice and data communication lines.

“The main challenge is that often you do not know what truly is behind the walls or above the ceilings until you open them up,” Block said. “So it takes a lot of that preplanning process away, as you just have to go in and figure it out.”

There are also challenges when there is not enough space above ceilings to add additional lighting or devices, as well as inadequate infrastructure to power those devices within the existing spaces, he said. 

Likewise, the spaces between walls in many historic buildings weren’t designed for new technologies.

“A lot of coordination with other trades needs to happen—not just before the job gets started, but also as the job goes on,” Block said. “Often, as we’ve demoed out, we realize that it’s going to be a lot more difficult than what we thought it would be.”

To overcome these challenges, the team at Block Electric coordinates with a project’s wall and ceiling contractors, the mechanical contractor involved with the ductwork and the plumbing and window contractors if the owner is upgrading all these systems.

“We love doing restoration projects—the more [difficult] the challenge, I think the better we are,” Block said. “Resolving problems and coming up with solutions is something that we take a lot of pride in.”

Electricians play a crucial role when it comes to retrofitting existing buildings, said a Department of Energy (DOE) spokesperson for the agency’s Building Technologies Office (BTO) in the Office of Energy Efficiency and Renewable Energy.

“Building electrification can be complicated, particularly when buildings and communities are equipped with outdated electrical infrastructure,” the spokesperson said. “Challenges include upgrading local grid and building electrical systems and installing on-site solar, while avoiding costly upgrades to local and building electrical infrastructure.”

Furthermore, smart and low-power electrification solutions such as 120V heat pumps and heat pump water heaters, as well as load management systems, need to be deployed to support affordable transitions to electrified buildings. 

Electricians also must be aware of the effects of load reduction on electric retrofits because measures such as improving building envelopes will decrease electricity loads. 

The DOE and its national labs support research in these areas through experiments and field demonstrations, and the electrician workforce is “critical” to these efforts. 

“A big challenge arises when you replace building equipment that runs on fossil fuels with something that runs on electricity instead,” the spokesperson said. “The issue here lies with the building’s electrical cables. They’re designed to handle only a certain amount of electricity flowing through them.”

When electrifying energy-­intensive equipment, major electrical cables and possibly the building’s electric service panel may need upgrading. 

Starting with efficiency improvements can sometimes obviate the need for these electrical upgrades, particularly if a smaller piece of equipment is electrified, because improved efficiency may lower the electrical needs enough to offset the need from equipment electrification. 

When retrofitting historic buildings, it’s crucial to preserve as much of the original structure as possible. With limited options for envelope upgrades, electrical loads can remain high, making the overall retrofit more difficult. Aesthetic preservation requirements may limit visibility of mechanical systems, therefore dictating additional challenges for routing electrical systems.

“The challenge is to improve the insulation while leaving those original structures intact,” the spokesperson said. “Through BTO’s envelope campaign, we recently celebrated a retrofit project that overcame this challenge for a historic army building—B246, home to the Army’s oldest active-duty infantry unit.”

Electrical contractors can mitigate these challenges during retrofits by understanding the effect of building envelope changes, collaborating with HVAC designers regarding new building loads, advocating for measures that will decrease loads and identifying ways to avoid costly transformer and panel upgrades. They should also consider cross-training and upskilling in HVAC design or energy assessments.

“It’s important for contractors to innovate by identifying new products or other low-power electrification solutions to avoid revamping existing infrastructure,” the spokesperson said. “Enlisting ­multidisciplined contractors who are capable of thinking of the building as a system rather than individual components will lower the challenges and costs of an overall retrofit and increase the likelihood of meeting the client’s needs.”

The BTO offers free online resources and facilitates access to training, particularly for deploying highly efficient electric mechanical systems such as heat pumps and heat pump water heaters through the Building Science Education Solution Center. Best practice guidance for residential construction based on building science principles can be found at the Building America Solution Center.  

For more on ECs’ experiences upgrading historic buildings, check out “Bringing Buildings Into the Modern Age,” from the June 2023 issue of ELECTRICAL CONTRACTOR.

landmarks illinois