Retro-Commissioning and EBCx

Why buildings drift

A commercial building is commissioned once, at handover, and then operated for decades by people who were not there. Setpoints get overridden during a complaint call and never reset. A damper actuator fails and the sequence quietly works around it. A schedule gets extended for a one-off event in 2019 and nobody changes it back.

None of this is negligence. It is what happens to every building, and the accumulated effect is substantial. In buildings older than about ten years, the documented sequence of operation and what the building actually does are rarely the same document.

What we find, repeatedly

• Equipment running outside occupied hours. Air handlers, pumps and lighting running evenings, weekends or continuously, because a schedule was changed and never restored.
• Economizers not working. Stuck, disconnected, or manually overridden. The most common defect we find in Canadian commercial buildings, and it costs money in both heating and cooling seasons.
• Simultaneous heating and cooling. Reheat fighting cooling in the same zone, usually because a setpoint or a valve has drifted.
• Static pressure and reset strategies disabled. Fans running at fixed speed where they were designed to modulate.
• Sensors out of calibration. A temperature sensor reading three degrees high makes an entire zone behave wrongly, and nothing on the BAS says so.
• Overrides nobody remembers. Points forced into manual years ago during a repair.

How the process runs

1. Planning — establishing current intended operation from drawings, sequences and the operating team's knowledge.
2. Investigation — trend data collection from the BAS, functional testing of major systems, and site observation across representative conditions.
3. Findings — a list of deficiencies with energy impact, cost to correct, and priority.
4. Implementation — corrections carried out by your controls contractor or ours, with the sequence documented as it is changed.
5. Verification — post-correction trending confirming the systems now do what the documentation says.
6. Persistence — a handover to your operating team so the building does not drift straight back.

Persistence is the whole problem

Retro-commissioning savings degrade if nothing changes about how the building is operated. A building that was corrected in 2024 and never reviewed is often halfway back to where it started.

We handle this by documenting the corrected sequences properly, briefing the operating team on what changed and why, and recommending a trending routine that surfaces drift early. Where an owner wants it, we review annually. It is a small ongoing cost against savings that would otherwise quietly disappear.

Funding

Save on Energy operates a dedicated Existing Building Commissioning stream in Ontario with its own program requirements, distinct from the main Retrofit Program. Where a project qualifies, the study and implementation can both attract support. We scope to the program's requirements from the outset rather than retrofitting an application onto a completed study.