DEC REQUEST DS2012-019 STAFF ANALYSIS

ISSUE: DS2012-019. Petitioner seeks a Declaratory Statement on an interpretation of Table 502.1.1.1(2) of the Florida Building Code, Energy Conservation.

Petitioner in DS2012-019 seeks clarification of the following questions:

1. In Table 502.1.1.1(2), which is the correct insulation level for Roofs, an R-value of 38 or a U-factor of 0.033 which equates to an R-value of 30? If the correct answer is R-38, then the corresponding U-factor should be 0.025.

2. If the answer to Question 1 is an R-value of 38, what measures will be taken to correct the error, including correction of the values in the compliance software?

Situation:

Ms. Lorraine A. Ross, representing The Dow chemical Company, seeks clarification of code regarding the correct insulation level required for commercial building renovations and alterations by Table 502.1.1.1(2) in the 2010 Florida Building Code, Energy Conservation. Dow has been working with several insulation distributors, including G. Prouix of Fort Lauderdale, BlueLynx of Miami and All Interior Supply of Orlando and Hialeah, firms that are often asked questions regarding insulation requirements of the Florida Energy Code. Dow is committed to providing complete and accurate information regarding compliance with the Energy Code to its customers, including distributors, home builders, architects and other design professionals. To that end, Dow, along with these distributors, found that there is a discrepancy in insulation values for insulation levels for renovation and alteration of commercial roofs in Table 502.1.1.1(2)

Background:

1. The original draft of the “Floridafied” version of IECC Chapter 5 that went before the Energy Code Work Group in 2010 read as shown below. It required an R-40 for the prescriptive roof for shell buildings and did not break out criteria for renovations and alterations. The 2009 IECC required R-38 for “attic and other” roofs; metal buildings and “insulation entirely above deck” had lower requirements. Florida’s levels were supposed to be 20% more stringent than those in 2007, based mostly on the envelope.

502.2.1 Roof assembly.

502.2.1.1 Shell buildings, renovations and alterations. The minimum thermal resistance (R-value) of the insulating material installed either between the roof framing or continuously on the roof assembly shall be as specified in Table 502.1.1.1 502.2(1), based on construction materials used in the roof assembly.

Exception: Continuously insulated roof assemblies where the thickness of insulation varies 1 inch (25 mm) or less and where the area-weighted U-factor is equivalent to the same assembly with the R-value specified in Table 502.1.1.1 502.2(1).

TABLE 502.1.1.1 B5.1

ENVELOPE PRESCRIPTIVE MEASURES FOR SHELL

BUILDINGS¹

Building Element	Mandatory
Roof: Absorptance R-value (U-value)	≤ 0.22 R-40 (≤U-0.025) ≤ 0.027

2. The Energy Code Work Group felt that these requirements were too high for renovations and directed the contractor (FSEC) to come back with an option that was less stringent for renovations and alterations. Mod 4060 submitted by Mangesh Basarkar of the Florida Solar Energy Center (FSEC) proposed changes to prescriptive values in Table 502.1.1.1(2) as shown below. His rationale was that the latest ASHRAE and IECC codes for commercial buildings have R-38 (roof) …as the maximum recommended values. When recently asked whether the R-38 or U≤ 0.033 was the efficiency intended, Dr. Swami of FSEC verified that the minimum roof efficiency intended was R-38. The U-value provided was a typographical error; it should be U≤0.027.

TABLE 502.1.1.1 (2)

ENVELOPE PRESCRIPTIVE MEASURES

FOR RENOVATIONS AND ALTERATIONS¹

Building Element	Mandatory
Roof: Absorptance R-value (U-value)	≤ 0.22 R-40 (U≤0.025) R-38 (U≤ 0.033)

Staff Recommendations: Based on the above facts and circumstances, staff provides the following recommendations as answers to proponent’s questions:

Question 1:

To the question, In Table 502.1.1.1(2), which is the correct insulation level for Roofs, an R-value of 38 or a U-factor of 0.033 which equates to an R-value of 30? If the correct answer is R-38, then the corresponding U-factor should be 0.025., the answer is that the R-38 roof insulation value is correct; the corresponding U-value should be (U≤ 0.027). The U-0.033 conversion indicated in parentheses was a typographical error.

Question 2:

To the question, If the answer to Question 1 is an R-value of 38, what measures will be taken to correct the error, including correction of the values in the compliance software? the answer is that the program uses U-0.033 for the Roof R-value for renovations and alterations in the EnergyGauge Summit 4.0 program but can be changed quickly with no problem.