Tustin, CA Sign Regulations: Window Signs (2026)

Tustin City Code Section 9403e8 exempts "incidental signs mounted, painted, attached to, or placed upon windows and intended to be viewed from the exterior, unless prohibited in an approved Master Sign Plan, provided that the aggregate area of such signs do not constitute more than twenty-five (25) percent of the window area upon which they are placed." The definitions section, 9402, defines a window sign as any sign attached, painted or pasted on the interior or exterior of a window and intended to be viewed from outside, and clarifies that for calculating window area, a series of adjoining panes separated by mullions or panels on one building elevation can be combined into a single total.

That combination rule matters for storefronts with multiple small panes: the twenty-five percent ceiling is measured against the whole elevation's glass, not pane by pane. The exemption is also subordinate to any approved Master Sign Plan for the property; a center's plan under Section 9403h can prohibit window signs outright even where the twenty-five percent threshold would otherwise be met. Once window signage exceeds the twenty-five percent cap, it drops out of the exempt category and must instead comply with the standard sign permit application and review process in Section 9403a through c, run through the Community Development Department, plus the general prohibition on painted signs found among Section 9404's prohibited sign types unless approved as part of that permit process.