CASE STUDY: ARE REFLECTIVE COOL SHINGLES WORTH IT
With the recent release of cool shingles like the Timberline Cool Series from GAF and the $1,500 Energy Star Tax Credit for cool roofing materials, many folks are asking whether the any energy savings are worth the additional cost. We thought that it was a great question and decided to crunch the numbers and do a quick case study on the Timberline Cool Series Shingle to find an answer.
The Cool Roofing Facts:
Energy Star estimates that the average Heating & Air Conditioning Costs for Homeowners in the U.S. is $1,000 per year.
The Cool Roof Rating Council (CRRC) estimates that the average energy savings for reflective shingles to be between 7% and 15% of cooling costs.
2010 Tax Incentives from Energy Star currently offer a $1,500 tax credit for choosing qualified Energy Star Cool Shingles.
In colder Northern climate zones of the United States, a cool roof may actually increase heating costs in the winter offsetting summer savings.
Shingles Used for Comparison: Timberline Prestique 30yr, Timberline Prestique Lifetime, and the Timberline Cool Series Lifetime.
Estimated Annual Cool Shingle Savings By Region
Unable to find an accurate breakdown of heating and air conditioning average expenses into their respective parts, we’ve made the estimation that in colder northern climate zones like Minnesota and Wisconsin, 33% of the average spent goes towards cooling and the other 67% to heating. In southern climate zones like Southern California and Texas, the opposite was estimated. *Calculations are made by multiplying the Average Cost of Air Conditioning (AC) with the 7% Minimum (Min) Savings estimated by the CRRC.
Colder Regions
$1,000 Avg. HC x 33% Cooling = $330 Avg. AC
$330 Avg. AC x 7% Min. = $23 Saved Per Year
Warmer Regions
$1,000 Avg. HC x 67% Cooling = $670 Avg. AC
$670 Avg. AC x 7% Min. = $47 Saved Per Year
Conclusions
Homeowners in northern climate zones should save a minimum of $23 a year on air conditioning costs with cool shingles. However, savings may be offset entirely by added heating costs in the winter months.
Those in southern states should see a minimum annual savings of $47.
COST DIFFERENCE BETWEEN TIMBERLINE PRESTIQUE AND COOL SERIES
Price quotes for products were acquired from a major nationwide supplier, as of the writing of this case study. For the purpose of this report, a 3,000 square foot roof (30 Squares) is used and the Timberline Prestique 30yr is included as a baseline for comparison. The following are estimated material costs for the shingles only:
Timberline Prestique 30yr
$24.50 Per Bdl. x 3 Bdl’s Per SQ = $73.50 Per Square
$73.50 Per SQ x 30 SQ’s = $2,205 Total
Timberline Prestique Lifetime
$26.60 Per Bdl. x 4 Bdl’s Per SQ = $106.40 Per Square
$106.40 Per SQ x 30 SQ’s = $3,192 Total
Timberline Cool Series Lifetime
$42.50 Per Bdl. x 4 Bdl’s Per SQ = $170.00 Per Square
$170.00 Per SQ x 30 SQ’s = $5,100 Total
Conclusions:
The Cool Series Lifetime shingle is well over double the cost of the 30-year shingle.
The Cool Series Lifetime shingle is 60% higher ($1,908) than the regular Prestique Lifetime shingles.
With the $1,500 Energy Start Tax Credit on materials, this difference is reduced to only $408.
Prorated Cost Over the Life of the Shingle
In prorating the Lifetime shingles, a 50-year life is assumed (as is done by most insurance companies). *Calculations are based on Total Product Cost divided by the Life Expectancy of the each.
Timberline Prestique 30yr
$2,205 / 30 Yrs = $73.50 Per Year
Timberline Prestique Lifetime
$3,192 / 50 Yrs = $63.84 Per Year
Timberline Cool Series Lifetime Without Tax Credit
$5,100 / 50 Yrs = $102 Per Year
Timberline Cool Series Lifetime With Tax Credit
$5,100 - $1,500 Tax Credit = $3,600 Total
$3,600 / 50 Yrs = $72.00 Per Year
Conclusions:
With the tax credit, the prorated yearly cost of the Cool Series shingle is about $8 more per year or 13% higher than the regular Prestique Lifetime.
When prorated over the expected lifespan of the product and the Energy Star tax credit is included, the lifetime cool shingle is a slightly better value than the 30 year.
Prorated Cost Adjusted For Energy Savings
*Calculations are made by subtracting the Minimum Annual Energy Savings (7%) from the Total Prorated Annual Cost.
Cool Climates: Timberline Cool Series Lifetime Without Tax Credit
$102 - $23 = $79 Per Year
Cool Climates: Timberline Cool Series Lifetime With Tax Credit
$72 - $23 = $49 Per Year
Warm Climates: Timberline Cool Series Lifetime Without Tax Credit
$102 - $47 = $55 Per Year
Warm Climates: Timberline Cool Series Lifetime With Tax Credit
$72 - $47 = $25 Per Year
FINAL CONCLUSIONS:
When adjusted for energy savings in cold northern climate zones:
Without the Energy Star tax credit, the Timberline Cool Series is not worth the additional expense.
With the tax credit, the Timberline Cool Series may be worth it to homeowners in sunny areas. Annual savings however may be offset by higher heating costs during winter months.
When adjusted for energy savings in warm southern climate zones:
With or without the Energy Star tax credit, the Timberline Cool Series shingle shows strong value and is worth the additional expense.