I have two floors and a full basement. We have 10 minutes left for your questions for Shell. In addition to your answer to Troy re skylights, they also provide solar heat gain when it's sunny but cold and therefore supplement the heating in your home. But, normally when installing skylights, therefore natural light, not for solar gain. BBQ King you are putting a hole in the fabric of your home.
Solar gain is part of the window placement when designing.
Look under Power Smart. It's just that easy. Our home is 6 years old. There is a product that is power smart endorsed called the 'power planner'. Do both sides.