Interpretation #6991

Original Request

Code Version: 2010
Code: EXTBLDG
Code Description: Existing Building
Chapter: 6
Section: 612.1
Topic: reroof insulation R value

Question

Is it the intent of Florida Building Code (Energy Conservation) Section 502--Table 502.1.1.1 (2) that if an existing building is reroofed that the insulation R-Value must be upgraded to an R-Value of at least 38? I was under the impression that the existing R-Value must not be decreased and not necessarily increased

Answer Published 06/13/2012 at 1:45 PM

No, unless the reroof cost equals or
exceeds 30% of the assessed value of
the structure or if the reroof is part
of a broader scope of work which
results in a cumulative cost equaling
or exceeding the 30% assessed value
threshold. However, existing levels of
R-Value may not be reduced.

Commentary

Reroofing is regulated as an Alteration Level 1 by the FBC, Existing Building Code. Section 601.2 indicates that the current level of energy efficiency may not be reduced, and section 612.1 directs one to the FBC, EC for energy conservation compliance. Section 101.4.1 of the FBC, EC provides direction to Table 101.4.1 for existing buildings. This Table indicates that building envelope renovations must comply with sections 402 or 502, subject to footnote “d”. This footnote makes clear that the reroof is exempt from further compliance with the FBC, EC if the 30% assessed value threshold is not equaled or exceeded. The roof insulation requirement of R-38 is applicable to new construction, additions and reroofs which exceed or are part of work the cumulative value of which equals or exceeds the 30% threshold, and then only if pursuing the prescriptive compliance path.