Making Room For Sun

I would like to add a bright, efficient sunroom to my house for an outdoors feeling during the winter and to help heat my home. What reasonably priced options do I have?—Peg N.




There is a vast array of sunroom options that would probably fit your needs, even on a fairly tight budget. Designs range from low-cost kits to elaborate decorative ones. Some models are designed to be do-it-yourself kits while others are delivered to your home already assembled.




While a sunroom can be an appealing addition, it’s probably unrealistic to expect it to reduce utility bills. A sunroom is most likely going to be an energy luxury, especially during the heat of the summer sun or the dark cold of a winter night. But to make a sunroom as energy efficient as possible, there are several considerations to pay attention to, including ceiling and wall insulation, thermal windows, drawable shades, and air venting. Also, consider some type of air heating and/or cooling, depending on how you want to use the room.




To use a sunroom to assist with heating your house, it needs the proper orientation to the sun, much thermal mass, and a method to move the solar heat into your house. The orientation should be within 15 degrees of true solar south. This is different from compass south and varies depending on your location in the country. Your local weather service should be able to tell you how many degrees true solar south varies from compass south in your area.




When attempting to provide heat for your house, you want the sunroom to capture as much solar heat as possible. Without heavy thermal mass to absorb this heat, the sunroom can overheat and much of the heat is lost back outdoors. Typical thermal mass materials are masonry (bricks, concrete, stone) and water in drums. The masonry thermal mass can be built into a wall or floor and can actually be an attractive addition. Warm air ducts are a common way to move the solar-heated air into your house.




The newer do-it-yourself sunroom kits have a professionally built look. I built a sunroom kit on the concrete patio of my house, and although it took me a month to do it, it looks very nice. Even the few manufacturers that sell only through authorized contractors who build it for you often allow you to assist in building it to lower the overall cost.




Sunrooms are classified as three-season (not winter usage) or year-round. You probably want a year-round model since you want to try to help heat your home with it. A year-round model will have double-pane thermal windows and a wood or thermally broken aluminum frame for efficiency. The thermal breaks are more important in colder climates, especially to control condensation since people often have plants in sunrooms. Three-season sunrooms typically have just single-pane windows and screens to be opened like a porch during the non-heating seasons.




Most sunroom kits bolt together like a huge erector set. All of the color-coded components, hardware, and fasteners are included.




Models using frames with a curved transition from the front to top are the most attractive, but more difficult to build. These often use wood frames instead of no-maintenance aluminum. If you want curved eaves and an attractive interior with no maintenance, choose a kit with composite framing (wood interior and aluminum exterior).




During the summer, sunrooms often overheat in the afternoon: adding some type of shading and ventilation is imperative. Exterior shading, such as solar screening, is the most effective and attractive. Most sunroom kits do have optional shading systems.