Portland, ME Sign Regulations: Window Signs (2026)

2's permanent building-mounted sign standards, sets the dimensional rules for window signs storewide. The combined area of every temporary and permanent window sign on a given window, including painted glass lettering and perforated vinyl decals that let occupants see out, cannot exceed 50 percent of that window's area. That combined window-sign area is excluded from the separate total sign-area cap that applies to all other building-mounted signage in Table 19-G, so a heavily signed storefront window doesn't eat into the business's overall building-mounted sign allowance.

Placement is restricted two ways: the sign must be mounted or displayed on the interior of the glass, not applied outside or projecting from it, and window signs are allowed only on first- and second-story windows, upper floors are off-limits. Illumination is narrowly limited to neon or single- and two-color LED lighting; internally-lit cabinet signs and other illumination types used elsewhere in the sign code aren't permitted in a window display. 3, alongside building-mounted directional and directory signs, so a shop owner can post window signage within the Table 19-Q limits without filing a permit application or paying the Building Authority's sign-permit fee, though the dimensional standards still apply even without a permit.