Methodology · Version 1.0

What ClimaCost knows, estimates, and cannot know.

A trustworthy screening tool should make its limits as visible as its results. This page explains which facts come from you, which signals come from public data, and which outputs are planning scenarios rather than forecasts.

Last reviewed July 16, 2026U.S. residential screeningNot a certified energy audit

The short version

ClimaCost helps you choose the next question, not buy the next machine.

The report combines your home and equipment details with a recent local climate profile. It screens for bill pressure, system-planning urgency, and likely diagnostic priorities. It does not inspect equipment, read your utility tariff, measure air leakage, calculate a Manual J load, or promise that a project will save a specific amount.

Provided by you

Direct inputs

ZIP, home size, approximate home age, and typical monthly energy bill.
Equipment type, equipment age, primary heating fuel, and recent repair history.
Thermostat behavior and comfort symptoms such as weak airflow or humidity.
Optional redacted bill text used only to improve the plain-language explanation.

From public services

Location and climate context

ZIP-to-city and state context from Zippopotam when available.
Recent daily temperature history from Open-Meteo when available.
Heating and cooling degree days calculated from a 65°F reference point.
State-level fallback assumptions when a live source is unavailable.

Bill pressure

A screening comparison, not a weather-normalized utility audit.

Your bill is screened against home size, state energy-price assumptions, home age, fuel, and the local climate profile. Because ClimaCost does not yet collect every bill date, separate electric and fuel usage, your utility tariff, occupancy, solar, EV charging, or other large loads, the result is labeled as a pressure screen. It should help you decide whether to investigate—not tell you that a specific appliance caused the bill.

System planning

Age, repairs, and symptoms determine the recommendation path.

A newer system with no recurring symptoms can land on “maintain and monitor.” Repeated repairs, older equipment, or multiple comfort problems can move the result toward diagnostics or replacement planning. Consumer recommendations do not use contact details, marketing consent, project timeline, or contractor lead value.

Money scenario

The displayed dollars translate 5%–15% of the entered annual bill.

The range is simple scenario math: your entered monthly bill multiplied by 12, then by 5% and 15%. It shows what a modest or stronger reduction in the total bill would mean in dollars. It is not a prediction that maintenance, insulation, ductwork, or new equipment will deliver that result. Actual outcomes depend on measured usage, rates, scope, weather, workmanship, and behavior.

Confidence and missing information

More text does not make a rough calculation precise.

Optional bill text can improve the explanation by identifying usage units, budget billing, demand language, or non-energy charges. It does not automatically increase the confidence of the numeric scenario. A more defensible estimate would require dated monthly usage, electric and fuel separation, current rates, equipment efficiency, measured home conditions, and project scope.

Incentive standard

Volatile rules show a verification date and an official source.

Federal tax information is checked against the IRS. Home Energy Rebate context is checked against the Department of Energy, while product qualification should be confirmed with ENERGY STAR, the program administrator, and the contractor before installation. ClimaCost does not certify eligibility or provide tax advice.

IRS Energy Efficient Home Improvement Credit DOE Home Energy Rebates Program ENERGY STAR Product Finder Open-Meteo Historical Weather API

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