Sources
Every number, and where it came from.
Calora states figures about people's houses and their money, so each one names its source. Nothing on this site is an estimate we invented.
Housing stock, by ZIP
On a phone, scroll the table sideways to see the oil-heat columns.
| ZIP | Town | Housing units | Built before 1980 | Oil-heated homes | Oil share |
|---|---|---|---|---|---|
| 06877 | Ridgefield | 9,587 | 62% | 5,649 | 61% |
| 06820 | Darien | 7,675 | 70% | 4,616 | 64% |
| 06880 | Westport | 10,370 | 62% | 4,588 | 47% |
| 06840 | New Canaan | 7,747 | 66% | 4,474 | 63% |
| 06897 | Wilton | 6,408 | 65% | 4,441 | 73% |
| 06824 | Fairfield | 12,468 | 72% | 3,089 | 26% |
| 06850 | Norwalk | 8,598 | 61% | 2,900 | 36% |
| 06883 | Weston | 3,822 | 75% | 2,485 | 70% |
| 06831 | Greenwich | 6,135 | 67% | 1,603 | 30% |
| 06830 | Greenwich | 10,911 | 72% | 987 | 10% |
| 06853 | Rowayton | 1,361 | 75% | 829 | 66% |
| 06807 | Cos Cob | 2,938 | 71% | 452 | 16% |
| 06890 | Southport | 1,921 | 61% | 355 | 20% |
| 06878 | Riverside | 2,787 | 69% | 187 | 7% |
| 06870 | Old Greenwich | 2,922 | 64% | 128 | 5% |
| All fifteen ZIPs, oil-heated homes | 36,783 | ||||
Source: US Census Bureau, American Community Survey 2024 5-year estimates (2020–2024), ZIP Code Tabulation Area level. Table B25034 (year structure built; pre-1980 is the 1970-79, 1960-69, 1950-59, 1940-49 and 1939-or-earlier lines) and table B25040 (house heating fuel; oil-heated is the "fuel oil, kerosene, etc." line). Retrieved August 30, 2026, from data.census.gov.
ACS figures are survey estimates and carry margins of error. We round shares to whole percent.
Other numbers we state
- $3,000–$6,000 a winter in heating oil
- For a large Fairfield County home. Derived from Connecticut heating-oil price data published by the Connecticut Department of Energy and Environmental Protection and typical annual consumption for a 3,000+ sq ft oil-heated home. portal.ct.gov/deep
- $35–$150 per shared lead
- The range contractors pay on Angi/HomeAdvisor, Modernize and Thumbtack. Source: the platforms' own published pricing and contractor-reported ranges.
- $40 copay on the Home Energy Solutions assessment
- The homeowner copay for the Energize CT / Eversource Home Energy Solutions assessment, as of April 2026. energizect.com
- The figures in a heat-loss report
- Modelled from the homeowner's own year built, square footage and fuel against the housing and price sources above. It is an estimate for that house, never a measurement, and the report says so.
Numbers change. If one here looks wrong, email calora@nanocorp.app and we will correct it or say why we disagree.