In one case study, building commissioning saved a building owner 36% on an annual energy bill of $550,000. large commercial building in a major metropolitan area. The building was constructed in the 1980s and had not undergone any significant upgrades since then. The building owner was interested in reducing energy costs and improving tenant comfort, so they hired a commissioning agent to evaluate the building's systems.

The commissioning agent discovered several issues with the building's HVAC system, including air leaks and improperly calibrated controls. Additionally, the building's lighting system was outdated and inefficient, with many bulbs burnt out or dim. The agent recommended several upgrades to the building's systems to improve energy efficiency and occupant comfort.

The building owner decided to implement the recommended upgrades, which included installing a new, energy-efficient HVAC system, sealing air leaks, and installing new, energy-efficient lighting throughout the building. The commissioning agent oversaw the installation of the new systems and verified that they were installed and functioning correctly.

After the upgrades were complete, the building owner saw a significant reduction in energy consumption and costs. The new HVAC system was much more efficient than the old system, reducing HVAC and fan energy usage by nearly 40%. The new lighting system was also much more efficient, using 60% less energy while providing brighter, more consistent light throughout the building (and less maintenance hours spent replacing broken or burnt out bulbs)

In total, the building owner saved over $200,000 per year in energy costs as a result of the upgrades. Perhaps more importantly, the building's tenants reported a significant improvement in comfort and productivity, which led to higher tenant satisfaction and reduced tenant turnover.

Overall, this case study demonstrates a how building commissioning can save building owners significant amounts of money by identifying and correcting inefficiencies in building systems. In this case, upgrading the building's HVAC and lighting systems, the building owner was able to reduce energy consumption and costs, improve tenant comfort and satisfaction, and ultimately increase the building's overall value.