Southborough, MA Sign Regulations: Window Signs (2026)

Section 174-11(B) defines a window sign as any sign consisting of individual letters or graphics painted or otherwise similarly affixed directly to, or hanging behind, the glass surface of a window or door and designed to be visible from the outside of any building. Subsection C(4) says that, unless the bylaw provides otherwise, there shall be not more than two of the four types of signs (wall, window, standing or awning) for each business establishment. A business with more than one street-level public entrance can add signs at each entrance, other than the wall holding the principal sign, each no larger than 15 square feet or 10% of the facade, whichever is less.

Subsection C(5) caps the aggregate area of wall, window and awning signs at the lesser of 10 percent of the facade of the business establishment or 50 square feet in districts fronting streets other than Route 9, or 75 square feet in districts fronting on Route 9.

The sign table in subsection D prints window rows for the Highway Business, Industrial and Industrial Park Districts, both on Route 9 and off it. A permanent window sign is limited to 10 square feet, or 10% of the total area of the exterior windows of the business establishment excluding doors, whichever is less, and 1 per business. A temporary window sign is limited to 25% of the window, and note 4 limits those to paper or posterboard only, never on a window that carries a permanent window sign. Temporary signs shall not be maintained for more than a thirty-day period unless proper sign permits have been obtained (C)(11).

Subsection C(3) applies the illumination rule to permanent interior signs designed to be visible through a door or window: white, steady, stationary light shielded and directed solely at the sign. No sign can be illuminated between 10:00 p.m. and 6:00 a.m. except signs identifying police or fire stations or businesses open to serve the public on site. Subsection C(2)(g) bars any depiction of sexual conduct on windows visible to the public. Under subsection E the Board of Appeals can grant a special permit for a sign exceeding the number or area limits, but never for a sign in a Residential District other than at a legal nonconforming use.