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Boulder County's sending new property values around May 1, 2027, and they'll be based on what homes sold for between July 2024 and June 2026, so most of that evidence is already in. We've looked at 8,728 of those sales, and the typical home sold for 0.8 percent below the value it carries now. 53 percent sold for less.
Honestly, Boulder County looks more like Denver than its other neighbors. The typical house sold for right at its value, and condos are down, at 4.7 percent below their value, with 66 percent of them selling for less. And 2026 sales alone ran 0.7 percent below the current values.
So for a lot of Boulder homes, the 2027 value may come in flat or even a bit lower. But when about half of homes sell below their current value, the county's model can easily leave some of them too high, and that's where a protest can really work.
That's what our free check's for. Once the notices are out in May 2027, it'll compare your new value with what genuinely similar homes near you actually sold for, in your own neighborhood with a similar building value per square foot, and tell you straight whether you'd have a case. Most people who use it get told not to bother, and we'd rather you heard that first.
Look up my Boulder County home
So here's how it works. Your notice of value should arrive around May 1, 2027, and you'll protest to the Boulder County Assessor by June 8. It's free, and it's pretty quick to do. The assessor's got to answer by the last working day of June, and if you still don't agree, you can appeal to the County Board of Equalization by July 15, which doesn't cost anything either.
Now the question in a Colorado protest is what your home was worth on June 30, 2026. So the evidence that really counts is sales of genuinely similar homes nearby from the two years before that date, and what homes sell for later doesn't help much. You don't need a lawyer for any of it, honestly.
Here's how sales compare with current values in each town. It runs from about 42 percent of homes selling below their value in Erie to 60 percent in Louisville, so the towns really aren't moving together.
| Town | Sales | Typical sale vs. current value | Sold below |
|---|---|---|---|
| Longmont | 2,561 | -1.1% | 55% |
| Boulder | 2,378 | -1.9% | 57% |
| Unincorporated Boulder County | 1,407 | +0.6% | 48% |
| Lafayette | 854 | +1.2% | 45% |
| Louisville | 560 | -3.3% | 60% |
| Erie | 445 | +1.4% | 42% |
| Superior | 393 | -1.4% | 57% |
Basically, Colorado taxes a home in two parts. From 2026, the city and other local districts tax 6.8 percent of your value after they've taken 10 percent off it, up to $70,000, and the schools tax 7.05 percent of the full value. At one Longmont home's own 2025 rates, a $500,000 home would pay about $3,255 a year, and a $40,000 cut would save it roughly $260. Rates vary by city and school district, and the 2027 ones aren't set yet, so those are estimates. Our free check uses your own home's rates from the county's records.
Also, if you're 65 or older and have owned and lived in your home for at least 10 years, Colorado's senior homestead exemption takes 50 percent off the first $200,000 of its value. You'll apply with the Boulder County Assessor by July 15. The state only funds it when its budget allows, so it's really worth checking whether it's being paid this year.
Just so you know, the sales comparison's our own, read from Boulder County's public parcel records on 2026-10-08. Boulder doesn't mark which sales were ordinary sales between strangers, so we've counted warranty and special warranty deed sales since July 1, 2024 for $50,000 or more, one home per recorded deed, for houses and condos built before 2024, and compared each price with the home's current value, which is basically the market as of June 30, 2024. Quitclaims and other deed types aren't counted, because they're pretty much always transfers within a family rather than real sales, so they don't really tell you what a home's worth. We've also left out the odd sale that's under half or over two and a half times the value. The town's the city in the home's address, so it probably includes some unincorporated homes too, and we only show a town that's got at least 100 sales.
And the protest steps are Colorado law, so they're the same in every county. The tax arithmetic's from House Bill 24B-1001, and the example rates are one Longmont home's own 2025 levies from the county's records.
If you spot an error, please write to hello@propertytaxbuddy.com and we'll correct it and say what changed.