Solar sunrooms can be a winter boon to homeowners
Q. I want a solar sunroom for inexpensive extra living space and to help heat our house. I would like to build a kit myself or make a sunroom from scratch. What things should I consider?
A. A sunroom can provide wonderful living space for your family. Although it is typically less expensive per square foot to have a sunroom built as compared to a typical room addition, it is still not inexpensive.
Many companies sell sunrooms that are often basically in kit form, but most want to also do the construction work for you. This is not only to make more profit, but building one is typically not as simple as it looks.
Most of these sunrooms use extruded aluminum frame members, which may be difficult to cut without the proper saws and blades.
I convinced a sunroom company, who always does the installation, to send the components to me since I am an experienced do-it-yourselfer and a mechanical engineer. It took me three weeks of hard work to build the sunroom over a concrete patio. They told me it typically takes two of their factory-trained workers only two days to build one.
In order to use the sunroom to capture enough winter solar heat to help warm your house, it should face due south or southwest. It should be open to the house or have fans to circulate the solar-heated air into the house. Adequate solar mass — from bricks, stone, water barrels, etc. — is needed to store the solar heat and minimize overheating.
A sunroom that is designed and oriented properly to capture solar heat will typically overheat in the summer. Since you plan to use it for additional living space, it will need summertime ventilation and movable shading. Even so, it will likely be uncomfortably warm on the hottest days. I installed a vented, tinted skylight in mine.
Building a sunroom yourself from scratch is the best way to keep costs down and capture the most solar heat. Depending upon your home’s orientation to the sun, trees, lot size, etc., you will have the design flexibility to build a nonrectangular sunroom to accomplish your goals of heat and extra living space.
For most do-it-yourselfers, using twoby-four lumber framing is easiest and least expensive. Draw up the basic design you desire. Visit local window contractors and home-center stores to see what size windows they have. Often, someone returned or did not end up buying their custom-size windows, and you can buy them at a deep discount. Plan your final size on them.
To use the sunroom year-round and for solar heating for your house, select doublepane windows as a minimum quality. Single-pane windows are less expensive, but they are typically only used on three-season sunrooms. Tall old storm windows can be effective and cheap for a three-season sunroom. Look for them at recycled building-product outlets, which are becoming more common.
Using standard lumber, a lean-to design of sunroom with a slanted glass front is easiest to build yourself. There is less framing to build and much less roofing. This design will capture a lot of solar heat during winter, but it is difficult to control the overheating during summer.
Since your family can be outdoors more often during summer, you may just close off the sunroom during the peak heat.
Q. My father has a small Amish-built log cabin. The walls are made of four-byeight logs. Even with the fireplace going, it is drafty and chilly. How can we add wall insulation to make it more comfortable?
A. One of the attractive qualities of this type of cabin is the log appearance. There is no good method to add wall insulation without covering the outdoor walls or losing too much interior floor space.
Adding more attic insulation would be effective. Make sure all the mortar on the walls is sealed and not leaking. Add an outdoor combustion air duct for the fireplace. This will reduce the drafts and make you feel warmer.