Boulder, CO Sign Regulations: Window Signs (2026)
Key Facts
- Exempt window sign max area
- 4 square feet
- Max height above grade
- 25 feet
- Max window coverage
- under 25% of window
- High Window ban threshold
- >4 sq ft at 12+ feet
- Governing section
- Land Use Code § 9-9-21(c)(1)(L)
Summary
Boulder exempts small window signs from a sign permit, but only within limits: Section 9-9-21(c)(1)(L) allows a non-illuminated window sign up to four square feet, no higher than twenty-five feet above grade, covering less than twenty-five percent of the window. A window sign over four square feet placed twelve feet or higher is a prohibited 'high window' sign under 9-9-21(b)(3)(D).
(D)High Window: A window sign exceeding four square feet in area twelve feet or more above the ground level...(L)Window: A non-illuminated window sign of no more than four square feet in area and placed no more than twenty-five feet above finished grade, if the total area of such signs fills less than twenty-five percent of the area of the architecturally distinct window, and such signs do not exceed twenty-five percent of the total allowable sign area for the building or business unit. The area of a window sign not exempt from permit requirements under this subparagraph is calculated as a part of and limited by the total allowable sign area for the premises.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Municipal Code: Supplement 167 Update 3).
Full Breakdown
Section 9-9-21(c)(1)(L) treats a small window sign as exempt from the city's sign-permit requirement, but the exemption carries several conditions. The sign must be non-illuminated, no larger than four square feet, and placed no more than twenty-five feet above finished grade. The total area of all window signs on a given window must fill less than twenty-five percent of that architecturally distinct window, and window signage citywide cannot exceed twenty-five percent of the building or business unit's total allowable sign area. Any window sign that does not qualify for the exemption is still allowed, but its area counts against, and is limited by, the same total allowable sign area that governs the rest of the property's signage.
The sign code separately prohibits a specific category of window sign outright. Subparagraph (b)(3)(D), 'High Window,' bars a 'window sign exceeding four square feet in area twelve feet or more above the ground level,' regardless of illumination. That means a window sign can be large only low on the building, or small if placed higher, and a big sign mounted high in a storefront window is not something a permit can authorize.
Illuminated window signs face further restriction: subparagraph (b)(3)(E) bars direct illumination of any sign in a residential or agricultural zone and imposes an 11:00 p.m. cutoff on indirectly or internally illuminated signs near residential property, unless the illumination is required for safety.
Violations & Fines
A window sign larger than four square feet placed twelve feet or higher above the ground violates the 'High Window' prohibition in Section 9-9-21(b)(3)(D) regardless of any permit. An exempt window sign that exceeds four square feet, covers twenty-five percent or more of the window, or is illuminated loses its permit exemption under 9-9-21(c)(1)(L) and must instead meet the standard sign-permit requirements of subsection (b)(2).
Frequently Asked Questions
Do I need a permit for a small sign in my storefront window in Boulder?
Can I put a large sign high in my window?
Can a window sign in Boulder be illuminated?
Sources & Official References
Other rules in Boulder
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Window Signs in Nearby Cities
How other cities in Boulder County handle window signs.