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21 st International Convention & Trade Show

21 st International Convention & Trade Show. Seeking Adventure … Advancing Knowledge. Roof Consultants Institute. Equivalent Uniform Annual Cost: A New Approach to Roof Life Cycle Analysis. Jim Hoff. Firestone Building Products. Roof Consultants Institute. Life Cycle Cost Problems.

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21 st International Convention & Trade Show

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  1. 21st International Convention & Trade Show Seeking Adventure … Advancing Knowledge Roof Consultants Institute

  2. Equivalent Uniform Annual Cost: A New Approach to Roof Life Cycle Analysis Jim Hoff Firestone Building Products Roof Consultants Institute

  3. Life Cycle CostProblems • How long do roofs last? • How much do roofs cost? • How do you compare roofs with different service lives?

  4. Life Cycle Cost ProblemsHow Long Do Roofs Last? Average Service Life Study Cash (1997) Schneider & Keenan (1997) EPDM 14.1 Years 17.7 Years Asphalt BUR 17.4 Years 13.6 Years

  5. Life Cycle Cost ProblemsHow Long Do Roofs Last? Manufacturer’s Warranty Period System Asphalt BUR Modified Bitumen Single-Ply 10 to 15 Years Type IV Felt MB Cap over Non-MB Base 45 Mil 20 Years and Up Type VI Felt MB Cap over MB Base 60+ Mil

  6. Life Cycle CostSystem Details / Est. Min. Service Life System details and warranty period based on data from NRCA 2004-05 Low-Slope Roofing Materials Guide (2005)

  7. Life Cycle Cost ProblemsHow Much Do Roofs Cost? • Initial Cost • Maintenance Cost • Replacement Cost

  8. Life Cycle CostInitial Cost / Replacement Cost / Maintenance Cost REPLACEMENT INITIAL SERVICE LIFE MAINTENANCE (SL) COST COST COST (Initial + $1.00) (Annual) Based on Warranty Period SYSTEM TYPE ($ / SF) ($ / SF) ($ / SF) Ballasted EPDM 15 Years $2.85 $3.85 $0.20 Ballasted EPDM 20 Years $3.00 $4.00 $0.20 Adhered EPDM 15 Years $3.25 $4.25 $0.20 Adhered EPDM 20 Years $3.45 $4.45 $0.20 Adhered EPDM 30 Years $4.00 $5.00 $0.20 Mech. Attached EPDM 15 Years $3.35 $4.35 $0.20 Mech. Attached EPDM 20 Years $3.55 $4.55 $0.20 Mech. Attached T’Plastic 15 Years $3.40 $4.40 $0.20 Mech. Attached T’Plastic 20 Years $3.65 $4.65 $0.20 Modified Bitumen 15 Years $3.25 $4.25 $0.20 Modified Bitumen 20 Years $3.70 $4.70 $0.20 Built-Up Roofing 15 Years $3.60 $4.60 $0.20 Built-Up Roofing 20 Years $3.80 $4.80 $0.20 Initial cost data derived from contractor survey. Replacement and maintenance cost data derived from Cash (1997).

  9. Life Cycle CostStandard Life Cycle Cost Model LCC = IC + MCPV + RCPV Where: LCC = Life cycle cost ($/ sq. ft.) IC = Initial Cost MCPV = Present value of all future maintenance costs RCPV = Present value of future removal and replacement costs In other words, how much money in today’s dollars do I need to pay all the costs associated with this roof over its service life?

  10. Life Cycle CostStandard Life Cycle Cost Model Replacement Cost Initial Cost $ Maintenance Cost Year 1 Year 2 Year 3 Year 4 Year 5 Year N $ Present Value

  11. Life Cycle CostStandard Life Cycle Cost Model Life Cycle Cost at Present Value (Dollars per Square Foot) $8.49 $7.81 15 Year MB 20 Year MB

  12. Life Cycle CostStandard Life Cycle Cost Model Life Cycle Cost at Present Value (Dollars per Square Foot) $8.78 $8.13 $7.81 15 Year Adhered EPDM (45 mil) 20 Year Adhered EPDM (60 mil) 30 Year Adhered EPDM (90 mil)

  13. Life Cycle CostEquivalent Annual Uniform Cost Model EUAC = (A/P, i, n) Where: EUAC = Equivalent Uniform Annual Cost A/P = Annualized cash flow or payment ($ / sq. ft.) i = annual interest rate (%) n = service life (years) In other words, what are my estimated annual payments over the service life of this roof?

  14. Life Cycle CostEquivalent Annual Uniform Cost Model Equivalent Uniform Annual Cost (Annual Dollars per Square Foot) $0.75 $0.68 15 Year MB 20 Year MB

  15. Life Cycle CostEquivalent Uniform Annual Cost Model Equivalent Uniform Annual Cost (Annual Dollars per Square Foot) $0.75 $0.65 $0.57 15 Year Adhered EPDM (45 mil) 20 Year Adhered EPDM (60 mil) 30 Year Adhered EPDM (90 mil)

  16. Life Cycle CostEquivalent Uniform Annual Cost $.81 $.77 $.77 $.75 $.75 $.69 $.69 $.68 $.68 $.66 $.65 $.60 $.57 Ballasted Adhered Mech. Att. Mech. Att. Modified Built-Up EPDM EPDM EPDM T'Plastic Bitumen Roofing 20 Year System 30 Year System 15 Year System

  17. Life Cycle CostConclusions • EUAC may be very useful in comparing the value of roof systems with different service lives. • Specification enhancements such as thicker membranes and redundant details appear to add tangible value. • Using the EUAC method, the life cycle costs of different roofing systems appear to be very close over the same time frames.

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