Smart thermostats are measured through several different lenses: household opportunity, field-tested energy savings, user behavior, and modeled market-wide outcomes. The figures below distinguish U.S. and local pilot results, company-reported studies, estimates, and forecasts so unlike measures are not treated as one universal savings rate.
Key Smart Thermostat Statistics
The most useful headline figures span adoption, savings, behavior, and measurement design:
- 45% of U.S. homeowners surveyed in 2016 planned to install smart systems or devices during a renovation, with connected thermostats among the top three systems.
- 74 million U.S. single-family homes were included in DOE’s 2015 RECS-based opportunity framing published in 2023, representing housing stock rather than smart-thermostat ownership.
- Heating and cooling represented $1,203 of a $2,188 annual household energy-cost example in DOE’s 2015 RECS-based illustration, or 55% of the example’s annual energy cost.
- Nest adjusted-gross heating-gas savings were 12.5% in the first reported California cohort, equal to 69 therms per home.
- Nest adjusted-gross heating-gas savings were 13.4% in the second reported California cohort, equal to 106 therms per home.
- Nest adjusted-gross cooling-electricity savings were 13.9% in the first reported California cohort, equal to 429 kWh per home.
- Nest adjusted-gross cooling-electricity savings were 16.1% in the second reported California cohort, equal to 388 kWh per home.
- The 2013–2015 BPA/FPUD Washington pilot installed 176 Nest thermostats, with 13 additional homes receiving submetering devices.
- The BPA/FPUD pre-post NAC/VBDD model estimated 841 kWh in mean annual net savings per home during the 2013–2015 pilot, equal to 4% of total household consumption.
- 82% of BPA/FPUD pilot participants kept Auto-Away enabled during the 2013–2015 pilot, while 64% remained on the Max Savings setting.
- More than 85% of BPA/FPUD participants reported being somewhat or completely satisfied with Nest in the 2013–2015 follow-up survey.
- Google reports average Nest heating savings of 10% to 12% across multiple real-world studies, mainly involving U.S. and UK customers.
- Google’s multi-study summary reports average Nest cooling savings of 15%, while noting that homes and baseline settings differ.
- Google says its typical savings estimate translates to $131–$145 per customer-year at typical energy costs, depending on household baseline and prices.
- Google’s real-world Nest savings estimate can pay back the thermostat in under 2 years, although actual payback depends on price, incentives, energy costs, and baseline use.
- Google estimates cumulative Nest savings at 200 billion kWh from 2011 to early 2026, using a modeled worldwide estimate based on U.S. and UK study results.
- Google estimates $14 billion in cumulative Nest user energy-cost savings from 2011 to early 2026, using U.S., Canadian, and UK cost calculations.
- DOE’s early simulations predicted 0% to 3% savings for most modeled homes under one algorithm condition and 5% to 8% under a more advanced condition, rather than reporting field measurements.
Contents
- Household adoption and market reach
- Heating and cooling savings data
- Pilot results for electricity, gas, and runtime
- Use, comfort, and energy-saving behavior
- Costs, payback, and residential opportunity
- Standards, rebates, and performance limits
Smart Thermostat Adoption Statistics and Market Reach
Adoption data is not yet a single clean ownership series. The available measures instead show renovation interest, the size of the addressable housing stock, and the energy-cost opportunity inside a typical U.S. single-family home.
In a 2016 Houzz/CEDIA survey, 45% of U.S. homeowners said they planned to install smart systems or devices during a renovation. Connected thermostats were among the top three systems, but the survey covered smart systems broadly and does not establish that 45% planned to install a thermostat specifically. DOE, “Connected Thermostats Offer Gateway for Increasing Energy Savings”
DOE’s 2023 benchmarking presentation used 74 million U.S. single-family homes in a 2015 RECS-based opportunity framing. That is an estimate of housing stock used to frame potential, not a count of smart-thermostat owners. DOE/NREL, “Benchmarking Smart Thermostats”
The same illustrative home example assigned $2,188 per home-year to average annual household energy costs, including $1,203 for heating and cooling. DOE presents the heating-and-cooling share as 55% of the example’s annual energy cost; these are illustrative energy-cost values, not smart-thermostat user averages. DOE/NREL, “Benchmarking Smart Thermostats”
Smart Thermostat Energy Savings in Heating and Cooling Studies
California utility filing results show why the denominator matters. Heating results are expressed as a percentage of heating gas usage and in therms per home, while cooling results are expressed as a percentage of cooling electricity usage and in kWh per home.
| California reported cohort | Nest adjusted-gross heating gas | Nest adjusted-gross cooling electricity |
|---|---|---|
| First cohort, PDF page 20 | 12.5%; 69 therms/home | 13.9%; 429 kWh/home |
| Second cohort, PDF page 25 | 13.4%; 106 therms/home | 16.1%; 388 kWh/home |
The first cohort also reported Nest participant heating-gas savings of 10.0%, compared with 5.0% adjusted-gross savings for programmable thermostats. Its modeled Nest adjusted-gross heating range was 11% to 14%, while cooling savings were 11.6% for participants and 13.1% for the programmable comparison, with a 9% to 19% Nest interval. California energy filing, “Table 1…; Table 2…”
The second cohort reported 9.7% Nest participant heating-gas savings versus 7.8% for the programmable comparison, with an 11% to 16% Nest interval. For cooling, participant savings were only 0.7% before adjustment, compared with 15.0% for the programmable comparison and a 10% to 22% Nest interval after adjustment.
These are two separately reported cohorts and should not be merged into one average. California energy filing, “Table 1…; Table 2…”
Smart Thermostat Pilot Results for Electricity, Gas, and HVAC Runtime
The BPA/FPUD Nest pilot provides a local Washington example from 2013–2015, rather than a representative national result. It installed 176 thermostats in qualifying homes and used 13 additional homes with submetering devices in the Franklin Public Utility District territory.
| BPA/FPUD model | Mean annual net savings | Model sample |
|---|---|---|
| Pre-post NAC/VBDD | 841 kWh/home-year | N=97 |
| ECAM+ | 745 kWh/home-year | N=140 |
| Fixed effects | 955 kWh/home-year | N=167 |
The pre-post NAC/VBDD estimate had a 337 kWh lower and 1,345 kWh upper 95% confidence bound. The same model equaled 4% of total household electricity consumption and 12% of estimated heating-and-cooling load, showing how the denominator changes the interpretation. BPA/FPUD, “Nest Thermostat Pilot Savings Assessment”
Pilot telemetry found that 82% of participants kept Auto-Away enabled, 64% remained on the Max Savings setting, and 11% did not have heat-pump settings enabled. These are observed settings within the pilot, not general-population adoption rates. BPA/FPUD, “Nest Thermostat Pilot Savings Assessment”
Smart Thermostat Use, Comfort, and Energy-Saving Behavior
User behavior affects measured outcomes because automated schedules, away detection, and seasonal adjustments change the baseline against which savings are calculated. In the BPA/FPUD follow-up survey, more than 85% of participants reported being somewhat or completely satisfied with Nest, a self-reported result from a utility pilot rather than a national satisfaction estimate. BPA/FPUD, “Nest Thermostat Pilot Savings Assessment”
Google recommends a small schedule change of 1°F or 0.5°C as an energy-saving adjustment and says Nest Energy History displays the last 10 days of heating and cooling activity. These are product guidance and feature-duration measures, not measured average savings. Google Home, “Improve energy savings with your Nest thermostat”
Google’s reported study summary includes several behavior-linked outcomes:
- UK independent studies found Seasonal Savings users saved an average 10% on heating bills over winter.
- Seasonal Savings added about 3% to 7% in cooling savings and about 3% to 8% in heating savings, depending on climate, in evidence summarized from ACEEE 2018 proceedings.
- Google’s multi-study summary reports average heating savings of 10% to 12% and average cooling savings of 15%, while noting that homes and baseline settings differ.
- Google’s before-and-after bill review included real customers in 41 U.S. states.
The company states that these program results involve voluntary participation, so individual savings are not guaranteed. Denominators also vary between heating use, cooling use, and bills. Google Home, “Improve energy savings with your Nest thermostat”
Smart Thermostat Costs, Payback, and Residential Energy Opportunity
Google translates its typical savings estimate to $131–$145 per customer-year at typical energy costs. It also states that real-world Nest savings can pay back the thermostat in under 2 years, while emphasizing that device price, incentives, energy prices, and baseline use determine actual payback. Google Home, “Improve energy savings with your Nest thermostat”
DOE’s 2023 presentation likewise said some savings estimates implied payback in under 2 years. That statement is conditional on unspecified savings estimates and is not a measured payback period for every home. DOE/NREL, “Benchmarking Smart Thermostats”
Google’s illustrative imaginary-customer model estimated 25% heating-and-cooling energy savings, but the company warns that the example may be overly optimistic because it assumes a constant 72°F setting around the clock before installation. That assumption is materially different from a measured average across ordinary homes. Google Home, “Improve energy savings with your Nest thermostat”
Google estimates cumulative Nest savings of 200 billion kWh since 2011 through early 2026 and cumulative user energy-cost savings of $14 billion. The kWh estimate covers Nest users worldwide and generalizes U.S. and UK real-world study percentages with an assumption that users opt in to available features; the cost estimate covers users in the United States, Canada, and UK, using national average commodity prices and exchange rates. Google, “Nest thermostats reach 200 billion kilowatt-hours in energy savings”
Smart Thermostat Standards, Rebates, and Measured Performance Limits
Measurement design is central to interpreting smart thermostat statistics. DOE’s benchmarking field-data example used more than 1,000 thermostats with 12 months of retrospective data, but the presentation describes a benchmarking approach rather than a randomized national trial. DOE/NREL, “Benchmarking Smart Thermostats”
DOE’s early simulation results predicted 0% to 3% savings for most homes under one thermostat-algorithm condition and 5% to 8% under a more advanced condition. These are forecasts from probabilistic U.S. home models presented in 2023, not field measurements; modeled homes and algorithm assumptions determine the ranges. DOE/NREL, “Benchmarking Smart Thermostats”
DOE’s simulation-driven benchmarking project had $400,000 in FY2024 funding and $800,000 in total funding to date on the project page. Those figures describe research funding, not consumer market revenue. DOE, “Simulation-Driven Smart Thermostat Benchmarking”
ENERGY STAR’s smart-thermostat FAQ describes a one-year, nationwide, auditable savings-test approach for energy-efficiency programs. That standardization goal matters because reported results can otherwise mix total household consumption, heating gas, cooling electricity, HVAC load, bills, modeled savings, and voluntary feature use. ENERGY STAR, “Smart Thermostats FAQs for EEPS”