Is porch a common noun?

Yes, the noun 'porch' is a common noun, a general word for any porch of any kind.

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

  • Porch Street, Portland, ME
  • Porch Light Productions (theater group), Glen Rock, NJ
  • Back Porch Cafe, Watertown, TN

"porch" is a regular noun