Complete question :
Insulated concrete forms (ICF) can be used as a substitute for conventional wood framing in building construction. Heating and cooling bills will be about 60% less than in a similar wood-framed building in upstate New York. An ICF home will be approximately 10% more expensive to construct than a wood-framed home. For a typical 1,800 ftsquared2 home costing $130 ftsquared2 to construct in upstate New York and costing $260 per month to heat and cool, how many months does it take for a 1,800 ftsquared2 ICF home to pay back its extra construction cost?
Answer:
150 months
Step-by-step explanation:
Wood framing Construction cost :
Cost per ft² = $130
Total cost for 1800 ft² :
1800 * $130 = $234,000
Heating and cooling cost = $260
An ICF home:
Construction cost will be approximately 10% more expensive :
Hence, total cost of ICF = (1.1) * 234000 = $257,400
Extra cost on construction :
$257,400 - $234000 = $23,400
Heating and cooling cost ; 60% less expensive = (1 - 0.6) * $260 = $104
Saving in heating and cooling = $260 - $104 = $156 monthly
Number of months it takes to pay extra cost on construction :
Extra cost on construction / saving in heating & cooling
= $23,400 / $156
= 150 months
