Out-of-Hours Waste & BMS Quick Wins
A building is empty two-thirds of its hours: reading the overnight base load, and the scheduling, setpoint and dead-band fixes that cost nothing.
10 min read · Jacob Willis, Net Zero Lead · Last reviewed July 2026
The cheapest energy project in commercial property is almost always the same one: make the building's operating hours match the occupants' hours. An office is empty around 103 of the week's 168 hours, and the load-profile lesson showed that what a building draws at 3 a.m. is the fastest test of how well it is run. This lesson turns that observation into method: how to read out-of-hours waste from half-hourly data, the BMS fixes that eliminate it for little or nothing, and why these savings quietly evaporate unless someone owns them.
In this lesson
- 01Reading the waste from half-hourly data
- 02The BMS fixes, in rising order of effort
- 03The multi-let complication
- 04Sources and further reading