Are Double-Pane Windows Worth It in Mississippi? Savings and Payback
Data updated October 12, 2026.
In the GlassBase heating and cooling model, replacing a single-pane window with a double-pane window in Mississippi saves 243 kWh per window per year: 147 kWh of heating load and 96 kWh of cooling load. At 2025 average prices in Mississippi from the U.S. Energy Information Administration (EIA), that is worth about $12 a year with a heat pump and air conditioner, or $15 with a gas furnace and air conditioner.
Simple payback in years = installed cost per window ÷ yearly savings per window. So if your quote is $118 per window, payback with a heat pump is about 10 years.
Payback for your quote
If you are replacing the windows anyway, enter only the extra cost of the more efficient window over the one you would buy otherwise.
Yearly savings and payback per window in Mississippi
Dollars saved per window per year, and the highest installed cost per window that energy savings pay back within 10, 20, 30 years.
| Heating and cooling | Saved per year | Pays back in 10 years at a cost up to | Pays back in 20 years at a cost up to | Pays back in 30 years at a cost up to |
|---|---|---|---|---|
| Heat pump + AC | $12 | $118 | $236 | $355 |
| Gas furnace + AC | $15 | $150 | $300 | $449 |
Dollar figures use Mississippi average prices, not your utility's rate. Electricity $0.1403/kWh: Mississippi residential average, 2025. Source: U.S. EIA, Electric Power Monthly, Table 5.6.B, residential sector, year-to-date through December 2025, retrieved 2026-10-06. Natural gas $1.63/therm: Mississippi residential average, 2025. Source: U.S. EIA, Natural Gas Prices: price delivered to residential consumers, and heat content of natural gas delivered to consumers, 2025, retrieved 2026-10-06. Heat pump COP 3.2, air conditioner COP 2.5, gas furnace efficiency 85%.
Energy saved per window per year in Mississippi
One window of 39 × 59 in (1 × 1.5 m), averaged over eight facing directions. Weather: 19 TMY3 weather stations.
| Upgrade | Heating saved, kWh/yr | Cooling saved, kWh/yr | Total, kWh/yr | Natural gas saved, therms/yr gas furnace |
|---|---|---|---|---|
| Single-pane → double-pane | 147 | 96 | 243 | 5.9 |
Simple payback leaves out changes in energy prices, interest, rebates, tax credits and maintenance. The single-pane and double-pane windows use values from the calculator's reference-window table. In Mississippi, each location uses the limits of its own ENERGY STAR zone (South-Central, Southern). kWh here measures heat, not electricity on a bill. Air leakage and the rest of the house are not modeled. Model version tmy3-hourly-iso13790/f4822a26309b, data run October 12, 2026. How the model works.
Calculate savings for your own windows
Other upgrades: Single-pane to ENERGY STAR: savings and payback in Mississippi · Double-pane to ENERGY STAR: savings and payback in Mississippi
ENERGY STAR limits and all upgrades: U-factor and SHGC for Mississippi. Compare states: window energy savings by state. Before you buy: is it worth replacing windows for energy savings?
Frequently asked questions
How is the payback period calculated?
Simple payback is the installed cost of one window divided by the money it saves on energy each year. In Mississippi, the model puts that yearly saving at $12 with a heat pump and $15 with a gas furnace. The calculation leaves out energy-price changes, interest, rebates and tax credits.
Why does this page not show a window price?
Window prices depend on the product, the size, the installer and the job, and GlassBase has no published source for them. Enter the price from your own quote to get the payback.
Will my windows save this much?
Not necessarily. The figures are for one window of 39 × 59 in (1 × 1.5 m), averaged over eight facing directions, in a typical weather year. Your result depends on the size and facing of each window, shading, your current windows and the ones you buy. The calculator takes these inputs for your ZIP code.