Total Cost of Home Ownership Calculator

Home details

Home type

Based on average existing housing stock energy use (EIA data).

Above-grade square footage

sq ft

Do not include basement or below-grade space.

Climate zone

Select a zone to estimate energy costs from square footage.

Monthly energy bills

Electric

Gas

Override estimates by entering your actual bills.

Mortgage details

Home price

Down payment

Interest rate

Upgrade goal

Net Zero Home: ~90% energy reduction

Estimated upgrade cost

Upgrade cost added to loan amount for the selected upgrade path.

Annual utility rate increases

Low estimate

High estimate

Historical avg: 6.75% · suggested high: 10%

Standard home
30-yr total (high rate)

—

mortgage + energy

Net Zero Home
30-yr total (high rate)

—

mortgage + energy

30-yr savings
Upgrade vs. Standard

—

at high energy rate

Savings → Mortgage
total savings (high rate)

—

paid off early

Monthly cash impact
yr 1 energy savings vs. delta

—

yr 1 net

Standard home — interest + energy

—

high rate · beyond home price

Upgrade — you keep

—

vs. standard · high rate

Savings → mortgage — you keep

—

vs. standard · paid off early

Costs beyond the home purchase price — 30 years

How to read this chart: Principal (home price) is excluded — it's the same regardless of upgrade choice. Each bar shows only what changes: interest paid on your mortgage (hatched, bottom) and cumulative energy costs (solid color, top). Lower bar = less you pay beyond the home itself. The two bars per group show low vs. high energy inflation scenarios.

Interest paid (all scenarios) Standard — low rate energy Standard — high rate energy Upgrade — low rate energy Upgrade — high rate energy

Enter inputs and click Calculate to generate chart.

Standard Home

Net Zero Home

Savings → Mortgage

Disclaimer — for illustrative and educational purposes only. Projections are estimates based on user inputs and modeled assumptions. This tool does not constitute financial, engineering, or energy advice. Actual results will vary.

What's included: Cumulative mortgage interest and energy costs over 30 years. Home purchase price (principal) is excluded as it is the same across all scenarios.

What's not included: Property taxes, homeowner's insurance, HOA fees, and maintenance costs. Federal tax credits and utility rebates that may reduce upgrade investment are not reflected.

Energy estimates: Climate zone estimates are derived from U.S. EIA residential energy consumption data. Net Zero Home assumes ~90% energy cost reduction; Net Zero Ready assumes ~65–70%. Results are most applicable in heating-dominated climates (Zones 5–7). Milder climates may see materially different results.

Mortgage: Assumes a standard 30-year fixed-rate loan. When upgrade cost is financed, it is added to the loan principal. The paydown scenario applies year-1 energy savings as extra monthly principal, with savings growing annually at the selected energy inflation rate.

Energy inflation: Historical U.S. residential utility rate average is approximately 6.75%/year. Future rates are not guaranteed. The range between low and high scenarios illustrates the financial risk carried by homes with high energy exposure.