It is perhaps better to build green than to retrofit a less energy efficient home. Still, to do this does pay in long term dividends and a higher comfort rating.

One example would be replacement windows with low-e and hydrophilic coatings, which limit infrared rays (heat gain) and cause water to roll off the pane with no residue.

The 100 gallon stainless steel water tank serves the dual function of providing your hot water needs and as a radiant floor heating system with a small electric pump. The hot water flows from the bottom of the tank through PEX flexible piping that is looped between the floor joists of the basement ceiling. The pump is activated by the heating thermostat.

Cementitious Foam (Airkrete) is a mineral based foam that solidifies and adheres to it's surface. It is blown into any wall cavity like the old cellulite, but does not compact or settle after it sets. It's insulation efficiency is also significantly higher than it's cousin.

There are wonderful new technologies emerging and being developed. The costs of retrofitting can be recouped in a few years and they provide beneficial living quality as well as helping reduce energy loss and carbon emission.