How we source these numbers

• Costs come from published sources: HomeGuide, Angi, HomeAdvisor, Cost Insight Hub and Inch Calculator. Each page names its sources.
• Sources disagree. We show the most commonly cited range, and note when a figure is rougher.
• Most ranges are national. Bay Area jobs are not priced separately in these sources. Where California figures exist, we show them.
• Installer-published numbers are labeled, because the seller has an interest in them.
• Water supply information comes from utilities’ annual reports. Any home can differ, so test at your tap.
• Calculators show their formulas and use assumptions you can change.

Figures were collected in November 2026. Nothing here is a quote.