My kids like AC/DC; so did I when I was their age. One of them wears my 20-year-old sweatshirts — they’re called hoodies, now. Things that are old can be made new again. I have every tie I have ever owned; a few of them are bound to come back in style. It’s the retro craze, and it even applies to HVAC.

Retrocommissioning a commercial building is a very well-understood concept — at least it is among most commercial contractors. Some building owners are still getting up to speed. As green, sustainable building practices take hold, and owners want facilities that qualify for Leadership in Environmental and Energy Design (LEED) points, retrocommissioning of existing buildings is becoming much more popular.

Here are two reasons retrocommissioning is on the rise. Up until recently, there was no enforceable requirement within the U.S. Green Building Council’s (USGBC) LEED program for a newly constructed, certified building to be commissioned. That turned out to be bad news, as some buildings were not performing to the level of green that had been anticipated during the design stage. That is now changing as the USGBC has realized that an innovative design does no good if the building and system are not performing. This important emphasis has also shifted to existing buildings that seek LEED status. The second reason that retrocommissioning is cool like an old sweatshirt is because a renewed interest in saving energy is taking hold in not only commercial buildings, but residential as well.

Think about this: At a time in the residential market when new home construction has slowed, and replacement sales may be slowing with homeowners’ reluctance to spend during a recession, they still have a need to save energy.

A lucrative opportunity in the residential market might be to perform energy audits, and then perform the necessary maintenance needed to improve system performance.

You may even discover some repair or replacement opportunities along the way.