Corrections
Cost figures age, jurisdictions change their fees, and we make mistakes.
When a number on this site is wrong, we change it and we log the change here. We do not quietly edit and move on. The original figure, the new figure, and the reason all stay visible.
Why we do this
Anyone can publish a cost estimate. What separates a useful cost estimate from a guess is whether the person publishing it will stand behind it in public when it turns out to be wrong.
A correction log is the cheapest possible proof that we will.
What counts as a correction
| Type | Handling |
|---|---|
| A figure was wrong | Logged below with old value, new value, and reason |
| A source changed — fee schedule, state law | Logged below, post updated, “last verified” date advanced |
| Routine quarterly re-verification, no change | “Last verified” date advanced, not logged |
| Typo, formatting, added link | Not logged |
Report an error
If a figure here does not match your local permit records, your actual quote, or a source you can point to — tell us. Include the post, the figure, and what you are seeing instead.
The most valuable messages we get are from contractors and estimators telling us where the model breaks. We would rather find that out at build ten than at build fifty.
Change log
9 September 2026 — Soft costs & Methodology: 750 sq ft cliff and NAHB $/sf check
Changed: Soft-costs post and Methodology now name the 750 sq ft impact-fee threshold (Gov. Code §66311.5) instead of “certain sizes,” clarify connection fees vs impact fees and school-fee rules, and explain why series soft costs only move ~$4,000 from 400→800 sq ft. Methodology adds an explicit small-unit premium decomposition of ~$400/sq ft ADU models vs NAHB Pacific custom ~$167/sq ft.
Reason: Readers could not verify the size rule or the NAHB sanity-check without those numbers. Phase totals were not restated.
Source: Gov. Code §66311.5, HCD ADU Handbook, NAHB Survey of Construction / Eye on Housing
5 September 2026 — Methodology sources revised, all posts
Changed: Removed a reference to a proprietary subscription cost database from the sources table on every post.
Reason: We do not hold that subscription. Listing it implied a level of access we do not have. Every source on this site should be one a reader can open and check without paying for anything, and it now is.
Replaced with: NAHB Cost of Construction Survey and NAHB Survey of Construction, both publicly accessible. Phase totals were re-checked against both and did not change materially.
5 September 2026 — Corrections policy established
This page was created. All published figures were re-verified against California HCD, EPIC-LA, and LADBS permit records on this date.
Format used for each entry:
[Date] — [Post title] Changed: [line item] from $X to $Y Reason: [what we learned and where] Source: [link]