The Luna plan is a great addition to any house plan. It has large windows on three sides to take in all the natural sunlight and views. Three season rooms are used primarily in the spring, summer and fall. They are typically added to an existing house with a deck or patio. They are separated from the rest of the house with an exterior door. They can also be heated and cooled separately from the home, if at all. This plan includes a fireplace to stay warm on those cool nights.