Are 8 foot high ceilings a lot better than 10 foot high ceilings for energy efficiency?
It’s actually changes in ceiling heights and skylight shafts where we find the most problems. Often times the vertical walls that separate conditioned space from the attic that these ceiling height changes create are not insulated properly, or the insulation falls away from the walls with time. So the first key is to either avoid changes in ceiling height that would lead to vertical walls separating conditioned and attic spaces, or to thoroughly inspect the installation of insulation at these locations. If you have consistent 10-ft. ceilings the only real energy cost is the extra wall area, which does have some summer and more winter effect. For typical, new, central Florida homes for example, the annual energy use increase will be in the $15 to $20 range going from an 8-ft. to a 10-ft. ceiling throughout the house. There are several other considerations that may come into play. One is that 10-foot high walls usually have taller windows and thus more window area; if so, the additional
