Historically, most of us don't want to buy our parents' homes. Today smaller homes are at the top of the list for many buyers. "Superized McMansions" are giving way to energy-efficient homes that are smaller. They use less energy. Your utility bills will be lower. Mutifunctional furniture and rooms, carefully designed interiors are what's important.
When you decide on your home, you will need to evaluate the cooling and heating systems with the help of your home inspector. Are they sized appropriately and in good working order? When were they last serviced? How about the windows? Are they single or double-paned. Feel for drafts around the edges of the doors. Is there any missing insulation in the attic or signs of mold in the basement?
Outside, remember that trees add lot to climate control. Deciduous (leafy) varieties help control the climate. In the summer, branches hide the sun and lower your cooling costs and in the winter, the empty branches allow the light and heat in reducing heating costs. If you have an organic garden, birds who make their homes in those trees can add positively to the mix.