Buildings account for a large amount of land use, energy and water consumption, and atmospheric pollution. For example, in the United States, they use 40% of the total national energy consumption (56% by residential dwellings), produce 38% of the total carbon dioxide emissions, and account for 12.2% of the total quantity of water consumed (2006). In this context, buildings with considerably reduced energy consumption are a key strategy to achieving energy savings and climate protection targets in both the residential and commercial/institutional sectors [ 1]. This article reviews a number of heating and cooling systems—existing and/or under development—available for residential buildings and briefly outlines some research projects and initiatives, as well as technical achievements in Canada and other developed countries over the last few years.