Boulder building & ADU permits
Recent permit activity, updated continuously.
Boulder lies northwest of Denver and is home to the University of Colorado. Under Colorado's HB24-1152, larger Front Range cities must allow ADUs. Boulder publishes its construction permits under CC0 and even carries an 'accessory' building-permit type, which Igni uses to help identify ADU activity.
Igni is tracking 763 residential and building permits in Boulder, CO — including 39 classified accessory-dwelling-unit (ADU) filings. The most active ZIP is 80304. The most recent filing Igni tracked was Nov 2, 2026. All records come from City of Boulder open data (ArcGIS), an official government open-data feed, and are refreshed continuously.
763
Permits tracked
39
ADU permits
5
Distinct ZIP codes
Nov 2, 2026
Newest permit
Recent permits
A sample of the freshest permits in this jurisdiction — ZIP and city only (no street addresses).
| ZIP | Permit type | ADU type | Valuation | Applied |
|---|---|---|---|---|
| 80304 | Residential | — | $724,600 | Nov 2, 2026 |
| 80304 | Residential | — | $47,946 | Nov 2, 2026 |
| 80301 | Commercial | — | $9,181 | Nov 2, 2026 |
| 80302 | Residential | Detached ADU | $49,288 | Nov 2, 2026 |
| 80301 | Residential | — | $1,162 | Oct 31, 2026 |
| 80304 | Residential | — | $2,526 | Nov 1, 2026 |
| 80304 | Residential | — | $18,000 | Oct 30, 2026 |
| 80305 | Residential | — | $472,000 | Oct 30, 2026 |
| 80301 | Residential | — | $3,727 | Oct 30, 2026 |
| 80302 | Residential | — | $80,000 | Oct 30, 2026 |
| 80303 | Residential | — | $11,430 | Oct 30, 2026 |
| 80301 | Commercial | — | $18,270,000 | Oct 30, 2026 |
| 80301 | Commercial | — | $1,500,000 | Oct 30, 2026 |
| 80301 | Commercial | — | $671,436 | Oct 29, 2026 |
| 80302 | Residential | Detached ADU | $20,000 | Oct 29, 2026 |
| 80305 | Residential | — | $165,000 | Oct 27, 2026 |
| 80302 | Residential | — | $13,766 | Oct 27, 2026 |
| 80301 | Commercial | — | $450,000 | Oct 27, 2026 |
| 80301 | Residential | — | $10,000 | Oct 27, 2026 |
| 80302 | Residential | — | $600,000 | Oct 28, 2026 |
Top ZIP codes by recent activity
ADU types in the recent set
Permit activity in Boulder
Igni counted 1,109 permits issued in Boulder over the last 12 months (Oct 2025 – Sep 2026) — up 29.1% on the 859 in the 12 months before. The forecast expects about 552 over the next 6 months.
Forecast: trailing mean, typical error ±23% in backtests one to six months ahead. How we forecast
| Permit type | Last 12 months | Year over year | Forecast, next 6 months |
|---|---|---|---|
| All permits | 1,109 | Up 29.1% | ≈ 552 |
| Residential building | 913 | Up 34.7% | ≈ 490 |
| Commercial building | 196 | Up 8.3% | ≈ 89 |
| Trade (electrical, plumbing, mechanical) | 0 | — | — |
| ADU | 52 | — | — |
Monthly figures
| Month | Permits | 10th–90th percentile |
|---|---|---|
| Oct 2023 | 71 | — |
| Nov 2023 | 76 | — |
| Dec 2023 | 72 | — |
| Jan 2024 | 64 | — |
| Feb 2024 | 64 | — |
| Mar 2024 | 65 | — |
| Apr 2024 | 78 | — |
| May 2024 | 74 | — |
| Jun 2024 | 70 | — |
| Jul 2024 | 89 | — |
| Aug 2024 | 70 | — |
| Sep 2024 | 63 | — |
| Oct 2024 | 84 | — |
| Nov 2024 | 52 | — |
| Dec 2024 | 65 | — |
| Jan 2025 | 68 | — |
| Feb 2025 | 78 | — |
| Mar 2025 | 62 | — |
| Apr 2025 | 84 | — |
| May 2025 | 88 | — |
| Jun 2025 | 61 | — |
| Jul 2025 | 84 | — |
| Aug 2025 | 60 | — |
| Sep 2025 | 73 | — |
| Oct 2025 | 105 | — |
| Nov 2025 | 54 | — |
| Dec 2025 | 82 | — |
| Jan 2026 | 73 | — |
| Feb 2026 | 76 | — |
| Mar 2026 | 80 | — |
| Apr 2026 | 110 | — |
| May 2026 | 92 | — |
| Jun 2026 | 119 | — |
| Jul 2026 | 116 | — |
| Aug 2026 | 90 | — |
| Sep 2026 | 112 | — |
| Oct 2026 (forecast) | ≈ 92 | 77–137 |
| Nov 2026 (forecast) | ≈ 92 | 91–138 |
| Dec 2026 (forecast) | ≈ 92 | 92–140 |
| Jan 2027 (forecast) | ≈ 92 | 92–144 |
| Feb 2027 (forecast) | ≈ 92 | 92–146 |
| Mar 2027 (forecast) | ≈ 92 | 92–146 |
Counts are permits issued per calendar month as Boulder publishes them to its open-data feed — not a complete census; a change in what the city publishes moves them too. The current month is left out, and the most recent months are provisional. A forecast is a statistical estimate with a range, not a prediction for any project. Informational only.
How long do permits take in Boulder?
Based on 2,728 Boulder permits applied for between Nov 2023 and Aug 2026, the typical (median) permit was issued 85 days after application, and the middle half of permits took 42–161 days. One in ten took longer than 297 days.
| Permit type | Median | Typical range | Permits |
|---|---|---|---|
| All permits | 85 days | 42–161 days | 2,728 |
| Residential building | 80 days | 38–161 days | 2,211 |
| Commercial building | 98 days | 63–160 days | 517 |
| ADU | 162 days | 98–242 days | 130 |
Typical, not guaranteed: individual permits vary with project scope, application completeness and plan-review workload. Days are calendar days from application to issuance; applications still pending are counted as not-yet-issued rather than dropped. Informational only, not legal advice. How we calculate approval times.
Housing law — Colorado
Colorado's HB24-1152 (2024) requires larger Front Range municipalities to allow at least one accessory dwelling unit, by administrative approval, wherever single-family homes are permitted — generally from June 30, 2025.
HB24-1313 (2024) requires qualifying transit-oriented communities to plan for greater housing density near rail and frequent-bus corridors, rather than imposing a statewide duplex mandate.
Boulder ADU rules
Boulder overhauled its accessory dwelling unit rules with Ordinance 8650, which applies to ADU proposals submitted on or after March 8, 2025, and brought the city in line with Colorado's House Bill 24-1152 — the 2024 state law requiring larger Front Range jurisdictions to allow an ADU wherever single-family homes are permitted. The new rules eliminated several long-standing Boulder barriers: the owner-occupancy requirement, parking minimums, minimum lot size, side-entrance screening, and the neighborhood 'saturation' cap that had limited how many ADUs a given area could have.
For a market-rate ADU, Boulder generally allows up to 800 square feet for a detached unit or 1,000 square feet for an attached unit (or 50 percent of the primary structure's footprint, whichever is less). The city offers a larger envelope — up to 1,000 square feet detached or 1,200 square feet attached — for a deed-restricted affordable ADU, in exchange for a rent cap aimed at households at 75 percent of area median income.
With owner-occupancy and the saturation cap gone, a code-compliant ADU is now far more broadly available across Boulder's residential lots than under the old code. Colorado's HB 24-1152 took effect statewide on June 30, 2025.
This is an informational summary — verify current rules with the city's planning/permitting department; not legal advice.
See also: Colorado ADU law and what is an ADU?
Data source
Sourced from City of Boulder open data (ArcGIS). CC0 — public domain (commercial use permitted).
Nearby cities — Colorado
Learn more about ADUs & building permits
Background reading on accessory dwelling units, building permits, and how Igni turns Boulder permit records into leads.
Boulder permit data — FAQ
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Does Boulder allow accessory dwelling units (ADUs)?
Get permit leads — Boulder
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Informational only, not legal advice. Headline counts reflect all permits Igni has tracked for this jurisdiction; the table shows recent activity. Housing law changes — verify current statutes before relying on this.