Brentwood, CA Sign Regulations: Window Signs (2026)

Brentwood Municipal Code Section 17.640.005 lists signs nonresidential properties may display without a sign permit, and subsection N governs temporary window signage directly: "Temporary window signs, limited to a cumulative display period of seven days per month, per establishment. Maximum sign copy area shall not exceed more than twenty-five percent of the aggregate window area." The seven-day allowance is cumulative across the month, so a business cannot post a sale banner for seven days, take it down, and post another unrelated temporary sign for seven more days in the same window within the same month; the total display time across all temporary window signs at that establishment is capped at seven days.

The 25% ceiling applies to the establishment's total window area, not each individual pane, so a shop with several storefront windows measures its combined glass area before sizing sale banners, holiday graphics or promotional posters. This exemption sits inside the broader "Signs allowed without sign permits: Nonresidential land uses" section, which also lists convenience signs, directional signs, and other categories a business may post without going through the community development director's sign permit process under Chapter 17.835. A window sign that either covers more than a quarter of the glass or stays up longer than seven cumulative days in a month loses the no-permit exemption and becomes subject to the chapter's general permit and prohibited-sign rules, including the Section 17.640.009 restrictions on illuminated, flashing or animated displays if the sign uses electronic elements.