This guide covers unincorporated Boulder County only. The City of Boulder issues its own permits; see home improvement costs in Boulder.
What each job was filed at
"Usual" is the middle permit: half were filed for less, half for more. "Middle half of firms" takes every firm with three or more permits in the trade, finds each firm's usual job, and shows the band the middle 50% of firms sit in; it is the number to hold a quote against.
| Job | Usual filed value | Middle half of firms | Permits (share priced) | Usual days to final | Pages |
|---|---|---|---|---|---|
| Electrical | $2,500 | $1,500–$5,000 | 723 (97.4%) | 28 | cost · compare firms |
| Plumbing & water heater | $3,556 | $2,691–$4,137 | 628 (97.0%) | 76 | cost · compare firms |
| Heating & cooling | $11,058 | $7,965–$16,221 | 1,917 (96.9%) | 50 | cost · compare firms |
| Windows & doors | $11,703 | $7,125–$11,998 | 838 (98.4%) | 91 | cost · compare firms |
| Roof replacement | $14,988 | $12,250–$21,626 | 1,524 (98.4%) | 50 | cost · compare firms |
| Generator | $15,000 | $9,750–$15,436 | 293 (96.9%) | 35 | cost · compare firms |
| Siding | $24,000 | $22,675–$37,000 | 132 (97.7%) | 148 | cost · compare firms |
| Remodel & repair | $27,000 | $15,719–$80,000 | 446 (95.3%) | 190 | cost · compare firms |
| Solar & battery | $28,000 | $22,275–$32,977 | 982 (97.9%) | 88 | cost · compare firms |
| Addition | $60,000 | $50,511–$194,952 | 185 (95.7%) | 279 | cost · compare firms |
The County's Accela permit system stopped taking new applications on 4 May 2026, so our data ends with April 2026 (2023-05 to 2026-04). Job values come from the Boulder County Assessor's permit file.
What moves the price in Boulder County
The home. Each cost page splits firms into thirds by the usual value of the homes they work on (Boulder County Assessor 2026 actual values). The County's single-family value figure is $1,122,000.
| Job | Firms on the least expensive third | Firms on the most expensive third |
|---|---|---|
| Windows & doors | $7,716 | $25,000 |
| Remodel & repair | $20,100 | $39,600 |
| Roof replacement | $12,350 | $19,157 |
| Addition | $51,375 | $73,500 |
| Heating & cooling | $8,472 | $11,340 |
| Siding | $37,000 | $29,728 |
| Electrical | $3,000 | $2,000 |
Figures from each cost page, data of 20 October 2026. Windows more than triple from one end to the other; siding and electrical run the other way.
The firm. In windows and doors the ten busiest firms usually file $17,518 a permit, the 75 firms with fewer than ten permits $9,500 (Boulder County windows cost page). Remodels run the other way: $15,719 for the ten busiest, $30,000 for the 239 smaller firms. One in ten remodel permits was filed under $3,700 and one in ten over $179,000, 49 times as much, so a remodel quote needs a scope sheet before it can be compared.
The season. Roofing permits peak in October (index 168, where 100 is an average month) and are fewest in January (45). Generator permits peak in April (184). We have no prices by month, so this is about crews' calendars, not discounts.
What a County permit costs
From the County's B33 fee sheet (read 26 October 2026):
| Fee | Amount |
|---|---|
| Building permit fee, first $2,000 of valuation | $89.24 |
| Each further $1,000 up to $25,000 | $15.35 |
| Plan check | 65% of the building permit fee |
| County use taxes | 1.335% on half the valuation |
| EZ BP technology fee | $8 |
By our arithmetic a $15,000 re-roof comes to about $585: $289 permit, $188 plan check, $100 use taxes and $8. The roofing permit guide covers the Class A rule and inspections; the solar and HVAC guides cover those permits.
Filed value is not the price
- It is what the applicant wrote down. Some contractors write the contract price, some the permitted part only. Nearly every permit carries a value (98.4% of roofing, 96.9% of heating and cooling).
- One permit type covers small and large jobs. A water-heater swap and a repipe share the plumbing type; a furnace and a full heat-pump system share heating and cooling.
- Thin rows. Only 9 siding firms and 12 addition firms have three or more permits, so those bands rest on few firms.
- The County only. Homes in Boulder, Longmont, Louisville and the other towns are not in this file.
Check a quote in five minutes
- Find your job in the table and open its cost page.
- Put your quote against the "middle half of firms" band. Inside it is normal for the County; above it, ask what the extra covers.
- Open the compare firms page, find the contractor, and read its usual filed value, permit count and finished share.
- Ask whether the price includes the County permit and the final inspection.
For one job across many cities, see roof replacement cost, HVAC replacement cost and what home projects cost by city.
How we know this
Every row is a trade with a Boulder County cost page: Boulder County Community Planning & Permitting building permits on homes in unincorporated Boulder County (the County's Accela permit layer), with issue dates and declared job values from the Assessor's permit file, in the window 2023-05 to 2026-04. Usual = median of the permits that carry a value; middle half of firms = 25th to 75th percentile of the usual value of firms with three or more permits in the trade; days = median from permit issue to completion. The home-value thirds, busiest-firm and spread figures are copied from each job's cost page and dated. Fees are quoted from B33; the worked figure is our arithmetic.
Numbers come from Boulder County Community Planning & Permitting building permits on homes in unincorporated Boulder County (the County's Accela permit layer, which stopped taking new applications on May 4, 2026, so the data ends with April 2026; the City of Boulder and the other cities issue their own permits), with issue dates and declared job values from the Boulder County Assessor's permit file, data through October 20, 2026. Nobody paid to be on this page and nobody can.
Compare every Boulder County roofer by usual job and finished share →
Questions
- How much does roof replacement cost in Boulder County?
The usual roofing permit in unincorporated Boulder County was filed at $14,988, across 1,524 permits, and the middle half of 128 roofers usually file between $12,250 and $21,626. Roofers on the most expensive third of homes usually file $19,157, against $12,350 on the least expensive third (Boulder County roofing cost page). Every re-roof must be a Class A assembly because the whole unincorporated county is a wildfire zone.
- How much does window replacement cost in Boulder County?
Windows and doors permits were usually filed at $11,703 (838 permits), with the middle half of 29 firms between $7,125 and $11,998. Home value moves it more than any other job here: $7,716 on the least expensive third of homes, $25,000 on the most expensive.
- How much do solar panels cost in Boulder County?
Solar and battery permits were usually filed at $28,000, with the middle half of 40 installers between $22,275 and $32,977. The ten busiest installers usually file $30,834 a permit and the 88 smaller ones $25,000, so ask whether a battery is in the quote.
- How much does a whole-house generator cost in Boulder County?
Generator permits were usually filed at $15,000 across 293 permits, with the middle half of 13 installers between $9,750 and $15,436. Permits peak in April (index 184, where 100 is an average month).
- How much is a building permit in unincorporated Boulder County?
The County's B33 fee sheet charges a building permit fee of $89.24 for the first $2,000 of valuation plus $15.35 per further $1,000 up to $25,000, a plan check fee of 65% of that, County use taxes on half the valuation at 1.335%, and an $8 EZ BP technology fee. By our arithmetic a $15,000 re-roof comes to about $585.
Build your own list
Every firm with that kind of permit on record. Pick what you value. The list moves.
Related guides
- Home improvement costs in Anaheim, CA (2026): what 8 kinds of jobs were filed at
- Home improvement costs in Boulder, CO (2026): what 9 kinds of jobs were filed at
- Home improvement costs in Citrus Heights, CA (2026): what 9 kinds of jobs were filed at
- Home improvement costs in Cleveland, OH (2026): what 12 kinds of jobs were filed at
For one city
- Do I need an HVAC permit in unincorporated Boulder County? The EZ BP permit, the County mechanical license and the fee math
- Do I need a roofing permit in unincorporated Boulder County? Yes past one square, with a Class A roof and a photo final
- Do I need a solar permit in unincorporated Boulder County? Yes: the B46 plan set, the $400 fee and the engineer's roof letter
- Permit Fees (B33) — Boulder County (accessed 2026-10-26)