Treasure Valley Cost Guides

COMPASS — the Community Planning Association of Southwest Idaho — estimates that 876,760 people lived in Ada and Canyon counties as of April 1, 2026. That is 150,688 more people than the 2020 Census count of 726,072, a gain of 20.8% in six years. The Idaho Business Review reported those estimates on May 18, 2026, after the COMPASS board accepted them on April 27, 2026.

Here is the part that matters for your wallet: people need houses, and houses need work. More rooftops means more furnaces, more water heaters, more roofs, more sprinkler systems, and more homeowners on the phone collecting bids. When demand climbs faster than the number of licensed crews in the valley, the homeowner who already knows what a job should cost is the one who does not overpay.

This page is the hub. It gives you the local numbers first, then points you to the individual cost guides.

These are all nine cities we cover, ranked by population. Population estimates come from U.S. Census Bureau QuickFacts, Vintage 2025 (estimates as of July 1, 2025). Median values of owner-occupied homes come from the American Community Survey 2020–2024 five-year estimates, also published through QuickFacts. Growth is measured from April 1, 2020 to July 1, 2025.

Zoom out to the two counties and the split is clear. Ada County has 546,141 residents, up 10.3% since 2020, with a median home value of $512,300. Canyon County has 275,123 residents, up 19.0%, with a median home value of $390,000. Canyon is the smaller and cheaper side of the valley, and it is adding people faster.

We are not going to put a number on this, because no one has a clean local dataset tying population growth to what a plumber charges in Nampa. What we can do is tell you what to watch for when you collect bids.

• Watch the calendar, not just the price. Star grew 84.6% and Kuna 30.8% since 2020. Those households compete for the same pool of licensed contractors, so the first thing to feel the squeeze is usually scheduling. Get a start date in writing.
• Old house or new house changes the job. Boise grew 1.1% and Garden City 6.1%, so work there leans toward replacing aging systems in older homes, where surprises hide behind the drywall. Fast-growing Star, Middleton, and Kuna lean newer — more predictable work, but often a larger house.
• Home size drives the top of the range. Eagle's median home value is $772,900 and Star's is $564,300, against $367,300 in Caldwell. Higher-value homes usually mean more square footage, longer pipe and duct runs, and bigger equipment. In those markets, expect quotes toward the upper end of any range — and ask the contractor to point at what specifically drives it.
• Ask where the truck starts its day. Plenty of companies serving Caldwell and Middleton are based on the Ada County side. Ask up front whether there is a trip or travel charge for your address, and whether it applies to the diagnostic visit as well as the repair.

Every dollar figure on this site is a range, and we label it an estimate. A real quote depends on your house, your access, your equipment, and who has an opening that week. The point of a range is simpler than a quote: it tells you whether the bid in your hand is normal, high, or suspiciously low.

• Get three bids. A range only helps if you have something to compare against it.
• Check what is included. Haul-away, permit fees, and disposal are the line items that move a bid from the low end of a range to the high end.
• Treat a bid far under the range as a question, not a win. Ask what is being left out.

The guides linked from this hub cover the jobs Treasure Valley homeowners ask about most, and each one is written for this valley — local permitting, local suppliers, local pricing — not a national average with a city name pasted on top.

Three rules govern every number we publish.

• Government data is stated plainly, with the agency named. The population and home value figures on this page are U.S. Census Bureau QuickFacts — Vintage 2025 population estimates and ACS 2020–2024 five-year home values. The valley-wide total is the COMPASS estimate for April 1, 2026, as reported by the Idaho Business Review on May 18, 2026.
• Company figures are attributed, never laundered. If a price comes from a contractor's own published guide, we name whose guide it is so you can weigh it accordingly.
• No invented precision. If we cannot source a number, we do not print one.

Quest Collective LLC runs this site out of Meridian. If a figure here is stale or wrong for your neighborhood, that is worth hearing about.