Sunrooms have become the latest home improvement projects for all homeowners today. Everyone wants to add a sunroom to his/her home. Sunrooms are places that add space to a home and add to its value. The major portion of the cost, up to 70%, incurred in construction is paid back as space as the value of the home increases on adding a sunroom. The cost of construction of the sunroom varies according to its size, the locality/area of the home, prevalent labor charges, quality of materials and a host of related factors including sunroom wall insulation requirements.

Two and three season sunrooms cost relatively less than year round or four season sunrooms. This is mainly on account of the superior insulation properties of four season sunrooms. One type of four-season sunroom is made using a wooden frame type enclosure. Here it is possible to install batt roll insulation in the walls. Batt insulation is made from mineral fiber, which is either rock wool or processed fiberglass. It is used as insulation material within walls as also in ceilings and floors. Usually this type of insulation is the least expensive among wall insulating materials. However, it needs to be installed very carefully for giving effective performance. It is best suited for stud spacing of 16/24 inches. Batts are available in standard lengths of 4 or 8 feet and in widths that fit securely between wood framing members. The typical R-value for batts is approx. R3 per inch of batt thickness.

Over batts rigid foam board type of insulation should be installed in the interior walls. These boards are available in several thicknesses and possess high insulating value ranging between R4 to R8 per inch of board thickness. When the sunroom is well insulated it will allow the heating/air-conditioning system in the house to extend also to the sunroom for maintaining high comfort levels.

During sunroom wall insulation it is essential to install two vapor retarders in the wall assembly for best results. You must check with an insulation contractor, architect or heating and air-conditioning contractor or a knowledgeable local person for his opinion whether in your region it is appropriate to install the vapor retarder on interior walls or on the exterior wall. Well-built four season sunroom walls usually comprise of four-inch thick nominal walls for added insulation making them more thermally efficient and more comfortable in the winter.

For three season sunrooms normal insulation or no insulation is used at all because they are intended for use only during summer, spring and fall. As winter usage is by and large excluded, these sunrooms are not designed for being heated and therefore need no arrangements of any sort for heat loss prevention. This drastically cuts down overall expenses that include material and labor costs involved in insulating walls of the sunroom with savings on ceiling and floor insulation costs also. This cost difference between three season and four season sunroom should however be viewed keeping in mind that four season sunrooms have a more utilitarian quality and their cost of usage is much less as they are used for the whole year as against eight to nine months for three season sunrooms. Such a cost comparison will be more realistic.