When homeowners are shopping for a sunroom, the most common question I receive is what is the difference between a 3-season room and all-season room?
An all-season room is a sunroom built to be heated and cooled all year long. In order for a room to be heated and cooled, it must pass RES check which is a report used to calculate if the new room addition complies with the IECC energy codes. In layman’s terms, to be heated/cooled by code, the new room must have a certain insulation value in the walls, roof, floor and the windows must be energy efficient. If the room does not meet the insulation requirements, it fails RES-Check and is not meant for year round use.
A 3-season sunroom is not heated and cooled and does not meet the energy codes. It can still be insulated, but if the amount of insulation in the room makes the room meet the energy codes, then it is no longer categorized as a 3-season room.
So essentially, a 3-season room is any room with a lot of windows, that is thermally isolated from the home that does not meet energy codes. Because the room does not meet energy codes, the temperature will fluctuate more in a 3 season room than in a room designed for year round use.
Check back for our next post as we dive into the difference between a 3-season room and a screen room!