(A) The following minimum energy values shall apply for all residential and commercial buildings:
(1) Roof R-38
(2) Wall R-20
(3) Basement Walls 13
(4) Floor R-19
(5) Window U-Factor .35
(6) Skylight U-factor .55
(B) The International Energy Code, 2018 Edition, published by the International Code Council Inc., is adopted as an optional/non- required standard with the amendments set forth in subsection (C) below. If an applicant requests to follow the code at the time of plan submission and the construction complies with the code, the town shall note such compliance on the Certificate of Occupancy.
(C) The following local amendments to the International Energy Code are adopted:
(1) IECC Table R402.1.1 and IRC Section NI 102.1.1. Tables are amended as follows:
TABLE N1102.1.1
INSULATION AND FENESTRATION REQUIREMENTS BY COMPONENTS (a)
CLIM A ZONE | FENESTR A- TION ON U- FACTORS (b) | SKYLI GHT U-FAC TOR | GLAZE D FENEST RA- TION SHGC (b) (e) | CEILI NG VALU E | WOOD FRAM E WALL R-VAL UE | MAS S WAL L R- VAL UE | FLOO R VALU E | BASEM ENT (c) WALL R-VALU E | SLA B (d) VAL UE DEP TH | CRAW L (c) SPACE WALL VALU E |
4 | 0.35 | 0.55 | 0.40 | 38 | 20 or 13+5 (h) | 8/13 | 19 | 10/13 | 10, 18" | 10/13 |
h. R-VALUES ARE M1NIMUMS. C-FACTORS ARE MAXIMUMS. WHEN INSULATION IS INSTALLED IN A CAVITY WHICH IS LESS THAN THE LABEL OR DESIGN THICKNESS OF THE INSULATION, THE INSTALLED R-VALUE OF THE INSULATION SHALL NOT BE LESS THAN THE R-VALUE SPECIFIED IN THE TABLE.
i. THE FENESTRATION U FACTOR COLUMN EXCLUDES SKYLIGHTS. THE SHGC COLUMN APPLIES TO ALL GLAZED FENESTRATION.
j. “10/13" MEANS R.10 CONTINUOUS INSULATION ON THE INTERIOR OR EXTERIOR OF THE HOME OR R-13 CAVITY INSULATION AT THE INTERIOR OF THE BASEMENT WALL.
k. R-5 SHALL BE ADDED TO THE REQUIRED SLAB EDGE R-VALUES FOR HEATED SLABS. INSULATION DEMI-I SHALL BE 18 INCHES BELOW GRADE.
g. FIRST VALUE IS CAVITY INSULATION, SECOND IS CONTINUOUS INSULATION OR INSULATED SIDING, SO + s MEANS R-13 CAVITY INSULATION PLUS CONTINUOUS INSULATION OR INSULATED SIDING. IF STRUCTURAL SHEATHING COVERS 40 PERCENT OR LESS OF THE EXTERIOR, CONTINUOUS INSULATION R-VALUE SHALL BE PERMITTED TO BE REDUCED BY NO MORE THAN R.3 IN LOCATIONS WHERE STRUCTURAL SHEATHING IS USED TO MAINTAIN A CONSISTENT TOTAL SHEATHING THICKNESS.
(2) IECC Table R402.1.3 and IRC Section N1 102.1.3 - Tables are amended as follows:
TABLE N1102.1.3
EQUIVALENT U-FACTORS (a)
CLIM ATE ZONE | FENEST RA- TION U- FACTO R | SKYLI GHT U-FAC TOR | CEILIN G U-FAC TOR | FRAME WALL U-FAC TOR | MASS WALL U-FAC TOR (b) | FLOOR U-FAC TOR | BASEM ENT WALL U-FACT OR | CRAW L SPACE WALL U-FAC TOR |
4 | 0.35 | 0.55 | 0.03 | 0.057 | 0.098 | 0.059 | 1/0 |
c. NON-FENESTRATION UT-FACTORS SHALL BE OBTAINED FROM MEASURENCENT, CALCULATION OR AN APPROVED SOURCE.
d. WHEN MORE THAN HALF THE INSULATION IS ON THE INTERIOR, THE MASS WALL UFACTOR SHALL BE A MAXIMUM OF 0.087
(3) IECC R402.3.3 and IRC.NI 102.3.3 Glazed Fenestration Exemption. Replace the printed area of “up to 15 square feet” with “up to 25 square feet” of glazed fenestration per dwelling unit shall be permitted to be exempt from U-factor and SHGC requirements in N 1102.1.1, exemption does not apply to U-factor alternative or total alternative approach.
(4) IECC R402.4.1.1 and IRC NI 102.4.1.1. Installation components of the building thermal envelope as listed in Table R402.4.1.1 shall be installed in accordance with the manufacturer's instructions and the criteria listed in Table R402.4.1.1 as applicable to the method of construction. The code official shall recognize the provisions listed in Table R402A.1.1 as a visual alternative to building or dwelling unit testing in R402.4.1.2.
(5) IECC R402.4.1.2 and IRC NI 1024.1.2. Building Thermal Envelope Air Leakage Testing option the building or dwelling unit shall be tested and verified as having an air leakage rate of 5 air changes per hour.
(Res. 2818, passed 12-18-14; Am. Ord. passed 12-18-14; Am. Res. 3180, passed 1-23-20)