What a professional window cleaning actually includes

Anyone can make the middle of a pane clear. The reason a professional cleaning looks different a week later is what happens around the glass.

• Tracks. The channel the window slides in collects grit, dead insects and mud. Left there, it ends up back on the glass the first time it rains.
• Sills and frames. Wiped down, not worked around.
• Screens. Taken down, washed, dried and put back in the opening they came from. Often priced as an add-on, so ask.
• The glass, done carefully. The glass industry treats a razor blade as a last resort, and window makers like Pella say never to use one. A professional clean should not leave scratches.

When you are comparing two quotes, this is the question to ask: what is in the price, and what is extra. Two quotes that include different things are not two prices for the same service.