Conforming General Living Space.

[Jacobus Rex]

Hi, 

On a website regarding real estate appraisal, I saw a discussion from 2009 talking about getting acceptance of a 3 season porch for inclusion within the general living area of the house(increased SF). Within the comments a real estate agent from the Maple Grove area noted that someone had installed hard wired baseboard heaters in a 3 season porch, thus enabling it to be considered part of the GLA.  It seemed that there was some discussion of fit and finish of the area, but the key component was the permanent heat source.    Does this make sense?  I'm asking because I am estimating work on a place that has a three season about 14x18, off the dining area, separated by the typical patio doors. I think it only has single pane windows but it's painted outside the same as the rest of the house and has a roof done same as the house. I have to revisit to know if it's insulated.   I don't know if there's any substantial value gained by putting in permanent heat source.  Obviously it would be neat to have that if living in the place. It makes it easily functional for temporary activity during the winter.  Thanks for your thoughts.