Question: An environmentally friendly 2,800- square-foot green home (99% air tight) costs about 8% more to construct than a same-sized conventional home. Most green homes can save 15% per year on energy expenses to heat and cool the living space. For a $250,000 conventional home with a heating and cooling bill of $3,000 per year, how much would have to be saved in energy expenses per year to justify this home (i.e., B-C ratio greater than or equal to one)? The discount rate is 10% per year, and the expected life of the home is 30 years.