We have these all over the place in my market and I am always at a loss as to what to call them. I see other appraisers call them all sorts of things. I call them Entry Porches when they are small (3x5 or so in front of the front door) but many of them are the same thing, just larger (typically around 15x4). My vision of a "porch" is a covered patio with railings...
I call them covered entries if they are just in front of the entry (3X5 or so). 15' X 4' I would generally call a covered walk. Covered porch I generally call if you can sit out there in a chair and allow people to walk by hence 5'+ in depth. The railings I don't know about your area but, here they do not have to have railings unless they are more than 18" off the ground level (safety issue). Patio's I tend to think of being located in the back/side yards. Porches to me are typically front entry area.
It would be a porch in our MLS and tax office. You know how that goes, they even count finished basement as GLA. :roll: :evil: As long as the comps have the same feature, no problem. But if I had a comp with a true porch and comparing it to the subject, I would probably label it as a covered entry for clarity in the adjustment grid.
I use covered entry for the even smaller ones. Large front porch for the nice big ones.
I consider a porch anything that is big enough for at least 2 chairs plus walking room and has a roof that is attached to and similar to the house roof. All porches are covered so I don't bother calling it a 'covered' porch. A covered patio has a roof that is different and less expensive than the house roof. At least that's my $.02