Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Better net savings option
Smart Thermostat
Insulation payback period
7.8
Thermostat payback period
1.7
Net savings difference over horizon
$250
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How to use this
- 1Enter insulation upgrade cost ($).
- 2Enter insulation annual energy savings ($).
- 3Enter smart thermostat cost + install ($).
- 4Enter thermostat annual energy savings ($).
- 5Enter years to project.
- 6Read your better net savings option on the right — it updates as you type.
- 7Hit Share to keep the scenario or send it to someone.
About this calculator
A smart thermostat is a cheap, fast way to cut energy waste through scheduling and setback temperatures, while an insulation upgrade costs much more upfront but delivers larger, more permanent energy savings by reducing heat loss through walls and attic. This tool compares upfront cost and annual energy savings for each to show which one pays back faster and which saves more over a longer horizon.
Worked example
Using the values the calculator loads with:
Inputs
- Insulation upgrade cost: 3500 $
- Insulation annual energy savings: 450 $
- Smart thermostat cost + install: 250 $
- Thermostat annual energy savings: 150 $
- Years to project: 10
Results
- Better net savings option: Smart Thermostat
- Insulation payback period: 7.8
- Thermostat payback period: 1.7
- Net savings difference over horizon: $250
What each field means
Inputs
- Insulation upgrade cost ($)
- The insulation upgrade cost used in the calculation, measured in $. Starts at 3500 $ so you have a working example on load.
- Insulation annual energy savings ($)
- The insulation annual energy savings used in the calculation, measured in $. Starts at 450 $ so you have a working example on load.
- Smart thermostat cost + install ($)
- The smart thermostat cost + install used in the calculation, measured in $. Starts at 250 $ so you have a working example on load.
- Thermostat annual energy savings ($)
- The thermostat annual energy savings used in the calculation, measured in $. Starts at 150 $ so you have a working example on load.
- Years to project
- The years to project used in the calculation. Starts at 10 so you have a working example on load. Accepted range: 1–25.
Results
- Better net savings option
- Returned as a plain value and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Insulation payback period
- Returned as a length of time. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Thermostat payback period
- Returned as a length of time. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Net savings difference over horizon
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Can I do both?
Yes, and most energy auditors recommend it — a smart thermostat pays back almost immediately, while insulation is a longer-term investment; doing both compounds the savings.
Which has the faster payback?
A smart thermostat almost always pays back in under two years given its low cost, while insulation paybacks of 5-10 years are common depending on your climate and current insulation levels.
Does insulation add resale value?
Yes — improved attic and wall insulation is increasingly noted in home energy scores and can be a selling point, an added benefit not captured in the raw payback math.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Insulation Upgrade vs Smart Thermostat Cost Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/insulation-upgrade-vs-smart-thermostat-cost
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/insulation-upgrade-vs-smart-thermostat-cost" target="_blank" rel="noopener">Insulation Upgrade vs Smart Thermostat Cost Calculator — RevenueLab</a> (2026).</p>
Source: [Insulation Upgrade vs Smart Thermostat Cost Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/insulation-upgrade-vs-smart-thermostat-cost) (2026).