How much can vacant-mode temperature setback actually save?

If a property is empty 60% of the month, why is it heated and cooled like someone’s home? That question has a well-studied answer — and because we’re building toward this capability, we want to put the honest math on record before we ship it, so you can hold us to it.

What the research supports

Temperature setback — easing the setpoint during unoccupied hours — is one of the most-studied home energy measures. Published estimates for meaningful setbacks generally land in the 5–15% range of heating and cooling energy, depending on climate, building envelope, equipment, and how much vacancy there actually is. The often-quoted rule of thumb of roughly 1% saved per degree of setback over an 8-hour period points the same direction.

We use a range deliberately. A leaky century farmhouse and a tight 2015 build will save very different amounts from the same setback, and any company quoting you one confident number for your house is selling, not measuring.

A worked example, conservative first

Take a property using 1,000 kWh in a month, vacant 60% of the time. At the low end (5% factor): 1,000 × 0.05 × 0.60 = 30 kWh saved. Mid (10%): 60 kWh. High (15%): 90 kWh. At $0.12/kWh that’s roughly $3.60 to $10.80 a month on electricity — real money over a year and across a heating season with gas in the mix, but not a number anyone should build a business case on alone. The honest framing: energy savings are a bonus that partially offsets the cost of supervision. The business case is the $1,000–1,500 incident that doesn’t happen.

Where this stands at HavenIQ — plainly

Automated vacant-mode temperature optimization is on our roadmap and not live. Our project rule is that no capability enters production until the one before it has passed every gate, and water supervision comes first. When energy optimization ships, founding pilot properties get it first, savings will be reported as ranges against your property’s own baseline — and this article is the standard we’ve publicly committed to measuring against.