Is stairs a proper noun

Answer 1

No, the noun 'stairs' is a common noun, a word for any stairs anywhere.

A proper noun is the name of a specific person, place, thing, or a title; for example:

• John Dalrymple, First Earl of Stair (1703)
• Stairs Street, Halifax, NS, Canada or Stairs Road, Amsterdam, NY
• "The Golden Stairs", a painting by Sir Edward Burne-Jones
• "The Dark At The Top of The Stairs", 1960 movie with Robert Preston, Dorothy McGuire