Editorial Policy and Corrections
Updated October 21, 2026
Cost of Owning publishes planning guides and browser calculators for household purchases, repairs and running costs. Our work combines public information with our own calculations. It is not a database of completed contractor jobs or a product-testing laboratory.
What a number represents
- Published fact: a price, specification, statistic or rule attributed to its source. Dates and geography matter; a manufacturer's list price is not an installed quote.
- Calculated result: arithmetic from stated inputs. It is only as applicable as those inputs.
- Scenario assumption: a chosen value for testing a decision, such as a repair reserve or holding period. It is not an observed average.
Prefer the source closest to the claim: the utility for a tariff, the manufacturer for a specification, and the relevant public agency for a rule or dataset. A source supports the statement attributed to it; it does not endorse our site or the rest of a scenario.
Original work and AI assistance
AI tools assist with research, drafting, code and graphics. They can make mistakes. Useful original work on this site includes worked budgets, sensitivity comparisons and calculators whose formulas are explained. AI assistance does not turn a hypothetical example into measured data.
We do not claim professional review, hands-on product testing, interviews, field measurements or a proprietary survey unless the individual page identifies the work and its evidence. Stock photographs illustrate a subject and are not evidence of an installation or test we performed.
Publication and update dates
A publication date records when an article first appeared. An update date records a substantive revision; it does not mean every price on the site was rechecked that day. A dated market snapshot should be read as a snapshot, even when the page remains available.
Corrections
Send the page URL, disputed figure, reason and a supporting source through Contact. Material calculation changes should include a note on the affected page explaining the previous limitation and the correction. Formatting edits do not need a new publication date.
October 21, 2026: corrected the solar payback calculator, which previously valued all generation at the retail electricity rate. It now separates direct use from export credits, includes explicit maintenance and inverter reserves, and shows annual checkpoints. The methodology was also revised to remove unsupported claims about access to actual contractor quotes.
Advertising and independence
The site has applied to Google AdSense. Advertising may support publication if approved. Ad code or a publisher ID does not imply Google approval or endorsement of our calculations. Advertisers do not determine model inputs or results. We do not sell contractor leads or collect calculator inputs for sales calls.
Use the limits as part of the answer
A planning estimate is a starting point. Compare the scope of written quotes, check the current tariff and confirm eligibility rules with the responsible provider. Where a result depends on future prices or repairs, test a less favorable case before relying on it.