But the operational and maintenance cost of a green-built home are significantly less. Heating and cooling accounts for about 45 percent of a homeowner’s annual energy consumption. Homes designed with passive solar and high efficiency windows require less energy to heat and cool; less workload on units also results in lower repair cost and a more years of service. The additional upfront cost of green construction is typically recouped within the first five years of ownership through lower maintenance and energy cost.