A. The 3-Season room is constructed with 2” think wall panels having the 3-Season Vinyl glazed or single pane glass windows. These rooms extend living space “3 seasons” of the year where efficient heating is not needed year round. The 4-season room has 3” thick wall panels thermally broken to allow for efficient heating and cooling the whole year. Insulated glass is used in the “all-season” room or an upgrade in the 3-season room.