Tiny Houses 2021

TABLE N1102.1.2 (R402.1.2) INSULATION AND FENESTRATION REQUIREMENTS BY COMPONENTa
CLIMATE
ZONE		 FENESTRATION
U-FACTORb		 SKYLIGHTb
U-FACTOR		 GLAZED
FENESTRATION
SHGCb, c		 CEILING
R-VALUE		 WOOD
FRAME WALL
R-VALUE		 MASS
WALL
R-VALUEi		 FLOOR
R-VALUE		 BASEMENTf
WALL
R-VALUE		 SLABd
R-VALUE
& DEPTH		 CRAWL
SPACEg
WALL
R-VALUE
1 NR 0.75 0.25 30 13 3/4 13 0 0 0
2 0.40 0.65 0.25 38 13 4/6 13 0 0 0
3 0.35 0.55 0.25 38 20 or 13 + 5h 8/13 19 5/13f 0 5/13
4 except
Marine		 0.35 0.55 0.40 49 20 or 13 + 5h 8/13 19 10/13 10, 2 ft 10/13
5 and
Marine 4		 0.32 0.55 NR 49 20 or 13 + 5h 13/17 30g 15/19 10, 2 ft 15/19
6 0.32 0.55 NR 49 20 + 5 or 13 + 10h 15/20 30g 15/19 10, 4 ft 15/19
7 and 8 0.32 0.55 NR 49 20 + 5 or 13 + 10h 19/21 38g 15/19 10, 4 ft 15/19
For SI: 1 foot = 304.8 mm.
  1. a. R-values are minimums. U-factors and SHGC 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.
  2. b. The fenestration U-factor column excludes skylights. The SHGC column applies to all glazed fenestration.
    Exception: Skylights may be excluded from glazed fenestration SHGC requirements in Climate Zones 1 through 3 where the SHGC for such skylights does not exceed 0.30.
  3. c. "15/19" means R-15 continuous insulation on the interior or exterior of the home or R-19 cavity insulation at the interior of the basement wall. "15/19" shall be permitted to be met with R-13 cavity insulation on the interior of the basement wall plus R-5 continuous insulation on the interior or exterior of the home. "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.
  4. d. R-5 shall be added to the required slab edge R-values for heated slabs. Insulation depth shall be the depth of the footing or 2 feet, whichever is less in Zones 1 through 3 for heated slabs.
  5. e. There are no SHGC requirements in the Marine Zone.
  6. f. Basement wall insulation is not required in warm-humid locations as defined by Figure N1101.10 and Table N1101.10.
  7. g. Or insulation sufficient to fill the framing cavity, R-19 minimum.
  8. h. The first value is cavity insulation, the second value is continuous insulation, so "13+5" means R-13 cavity insulation plus R 5 continuous insulation.
  9. i. The second R-value applies when more than half the insulation is on the interior of the mass wall.

N1102.4.1.1 (R402.4.1.1) Installation. The components of the building thermal envelope as indicated in Table N1102.4.1.1 shall be installed in accordance with the manufacturer's instructions and the criteria indicated in Table N1102.4.1.1, as applicable to the method of construction. Where required by the code official, an approved third party shall inspect all components and verify compliance.