An environmentally friendly $2$ comma $700$

$-$square$-$foot

green home$(99\%$ air$$ tight$)$ costs about $10$

$\%$

more to construct than a$$ same$-$sized conventional home. Most green homes can save $16$

$\%$

per year on energy expenses to heat and cool the living space. For a $$$$240$ comma $000$

conventional home with a heating and cooling bill of $$$$3$ comma $000$

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 $11$

$\%$

per$$ year, and the expected life of the home is $23$

years.