Answer:
2121.566 will be saved
Step-by-step explanation:
Extra cost=8%
Saving per year=15%
Extra Cost of home=250000*0.08=$20000
Let the energy saving required per year to justify the home=x
Extra cost paid = P.v of energy saving
20000=x*Annuity factor(10%@30 years)
20000=x*9.427
X=2121.566