Does window cleaning help a storefront?

Two sentences carry the whole published case for a clean storefront, and they come from two very different places. The first is 239 Exteriors' own description of what the service does for a building: clean windows help your home or business present a more polished appearance. It is a claim about how the front of a building looks, and it stops there.

The second comes from the glass industry. The National Glass Association opens its cleaning paper, Glass Technical Paper FB01-00, with this: "Glass usage and condition often affect our selection of where we live, work, shop, play and seek education." It is a general observation about people and buildings, placed at the start of a document whose real subject is how glass should be cleaned.

Read together, the two lines agree without overlapping. One speaks for the appearance of a single business; the other says glass condition is among the things that often affect where people choose to go. The service behind the first line is described under exterior window cleaning for homes and businesses.

Neither sentence carries a number. NGA's line says condition often affects a selection; it does not say by how much, for which kind of business, or against what else a shopper weighs. No source read for this answer measures foot traffic, sales or first impressions, and so this page prints none.

A figure about customers and clean glass would have to come from a study, and none was found. What can be said without one is narrower: the front glass is part of how a building looks from the sidewalk, and NGA counts condition among the things that affect where people choose to go. The same logic about appearance runs through cleaning windows before listing photos, where the audience is a buyer scrolling instead of a passerby.

A shop front may be one sheet of glass or many smaller panes divided by muntins. Either way, nothing published ties a number of customers to how that glass looks.

NGA's interest in condition is not mainly about looks. The paper's stake is stated early: "Since glass products can be permanently damaged if infrequently or improperly cleaned, glass producers and fabricators recommend strict compliance with the following procedures for cleaning glass surfaces." That warning cuts both ways. Glass left too long and glass cleaned the wrong way are both on the wrong side of it.

The routine trigger that follows is the condition of the glass rather than a date: "For routine maintenance, interior and exterior glass surfaces should be thoroughly cleaned as dirt and residue appear." The paper's quick-reference guide adds "DO NOT allow dirt and residue to remain on glass for an extended period of time" and "DO NOT allow splashed materials to dry on the glass surface". Whether one splashed deposit on shop glass does lasting harm is taken up at whether bird droppings damage glass.

Whether a particular pane has been marked is judged on the glass by a glass professional, not from a description. Why business glass is usually kept on a maintenance schedule is a separate question, answered at why business windows get cleaned so often.

Where a storefront's glass is tinted or reflective, NGA gives it a condition of its own: "Cleaning tinted and reflective glass surfaces in direct sunlight should be avoided, as the surface temperature may be too hot for optimum cleaning." Whether a given storefront's glass is tinted, reflective or filmed is something to establish before anything touches it, and how impact, Low-E, tinted and tempered glass differ sets out the rule that comes with each kind of glass.

NGA writes its exterior procedure for a building. It starts at the top of the building and works down "to reduce the risk of leaving residue and cleaning solution on glass that has already been cleaned." After the wash, "a window cleaning squeegee should be used to remove all of the cleaning solution from the glass surface."

Solution left on the glass to dry can leave a line, the mark called streaking, and the squeegee step is timed to leave no solution behind.