Having southern exposure will maximize the amount of sun your sunroom additions gets in every season of the year, and will make your sunroom more comfortable in winter than a sunroom addition with different exposure.
You may want a conservatory style addition, which has a glass roof as well as glass walls, but your climate might not allow it. If, however, you intend to use your addition as a dining area or extra bedroom, you might consider replacing the lower portions of the glass walls with knee panels to give the room a more traditional appearance. You'll also have an easier time installing electrical outlets in the knee walls.
You may want a conservatory style addition, which has a glass roof as well as glass walls, but your climate might not allow it. If, however, you intend to use your addition as a dining area or extra bedroom, you might consider replacing the lower portions of the glass walls with knee panels to give the room a more traditional appearance. You'll also have an easier time installing electrical outlets in the knee walls.
