If you’ve had work done on an existing facility, you probably already know your updates might trigger the need to comply with your jurisdiction’s latest energy code—especially if the update is substantial. But how can you navigate that in a way that makes financial sense? Maverick Allen and Gary McCoy, co-owners of Blink Energy Services, explained at the 2026 North Texas Facilities Expo how strategic updates can manage the energy efficiency of existing buildings.

Existing buildings are typically already compliant with the code unless they’re changed significantly, McCoy and Allen said. If the building is modified, your compliance strategy will change depending on the type of modification. All are governed by the International Energy Conservation Code (IECC) Chapter 5.

Repairs

A repair, according to the IECC, is the reconstruction or renewal of any part of an existing building for the purpose of its maintenance or to correct damage. This could be something like a glass-only window replacement because someone cracked a window, or replacing an existing door with the same type of door. “If you don’t have to pull a permit for what you’re doing, chances are you’re not going to have to [meet the latest code version],” McCoy explained.

Alterations

This comes into play when you’re significantly changing the building—in other words, any “construction, retrofit, or renovation to an existing structure other than repair or addition,” Allen explained. It could also involve a change in a building, electrical, gas, mechanical, or plumbing system that involves an extension, addition, or change to the arrangement, type, or purpose of the original installation. “Any time you start modifying the building envelope, you’re generally going to trigger energy code—touching the insulation or adding more windows,” Allen said.

With an alteration, the altered area must comply and it can’t cause the rest of the building to be less compliant than it was before. For example, you can replace windows with better windows, but you can’t increase them beyond the current allowances. “You can’t make a glass box and call it an alteration that’s compliant,” Allen said. Replacement windows and skylights have to meet requirements for U-factor and the Solar Heat Gain Coefficient (SHGC).

“If you’re adding windows, you may trigger a daylighting requirement,” Allen said. “In the energy code, if you have the ability to bring in natural light, we want to make sure we turn down the overhead lights to save energy. Now we have to add in a daylight sensor so the existing overhead lighting dims during the middle of the day.”

The roof can’t have the insulation or R-value reduced during an alteration, Allen added. Roof repairs can also fall into the category of an alteration if you need to reconstruct or renew the roof—a small leak probably won’t trigger a code compliance update, but the roof can’t be less compliant than it previously was.

“Any project with insulation above deck is required to bring the roof up to code,” McCoy said. “You can use an energy model to show compliance, referencing the existing building to show you aren’t making it less compliant than before.”

New HVAC or ductwork also qualifies as an alteration, and you may be required to install an economizer.

Additions

An addition is an extension or increase in the conditioned space floor area, number of stories, or height of a building or structure, Allen explained. There are two ways to comply with the requirements for additions:

• The addition alone must comply. This makes the most sense when the existing building is not very efficient and the new structure will have its own HVAC, lighting, and plumbing. The new addition should also be under the code’s fenestration limits.
• The existing building and the addition together must comply. This makes sense when the current building is fairly efficient, so no major upgrades are needed, or when the addition on its own would struggle to comply—for example, if it has a lot of glass. You also might opt for this strategy if you have long-term plans to upgrade the entire facility and are already planning to do repairs on the base building.

If you’re adding conditioned square feet, all of your mechanical equipment will need to comply with code, Allen said. You may be required to have the system commissioned if the mechanical equipment exceeds a certain size. Adding a boiler or any system for domestic hot water will also require compliance, as will lighting power and systems.

Change of Use

This applies when you’re changing the basic function of the building or a portion of the building that results in a change of occupancy classification, a change from one group to another group within an occupancy classification, or a change in use within a group for which there is a change in the application of code requirements—for example, converting an office building into apartments.

Why Commissioning is Important

Commissioning will ensure that your new systems and spaces are complying with code and performing the way they’re designed to. A device may not be installed correctly, or a contractor may forget to seal or caulk something. The commissioning process also includes training for your crew on how to operate equipment—a key step to keep the systems operating at maximum efficiency.

The process ensures small building issues don’t escalate over time and extends the life of your equipment; it also may be required by IECC. The process typically costs about 30 cents per square foot and payback runs around 13 months, McCoy said. The typical return on investment is $4.50 for every $1 spent, according to a 2009 study by the Lawrence Berkeley National Laboratory.