Title 16 - Buildings and Construction

16.110 Residential Code for One- & Two-Family Dwellings

16.110.N1112

Section N1112 of the International Residential Code for One- and Two-Family Dwellings is hereby added to read as follows:

SECTION N1112

LOCAL PRESCRIPTIVE COMPLIANCE ALTERNATIVE

 

N1112.1 General.  The building thermal envelope shall comply with the requirements of Sections N1112.2 Through N1112.3, the installed equipment shall comply with Section N1112.4, and the lighting equipment shall comply with Section N1112.5.

N1112.2  Mandatory requirements.  Compliance with this section requires that the provisions identified in Sections N1101.13 through N1104 indicated as “mandatory” and in section N1103.5.3 be met. The building thermal envelope shall be greater than or equal to the levels of efficiency and Solar Heat gain Coefficients in Table 402.1.1 or 402.1.3 of the 2009 International Energy Conservation Code.

                        Exceptions:

  1. 1.
    Supply and return ducts not completely inside the building thermal envelope shall be insulated to an R-value of not less than R-8.
  2. 2.
    Compliance with Tables N1102.1.2 and N1102.1.4 is not required.

N1112.3  Insulation and fenestration criteria.  The building thermal envelope shall meet or exceed the requirements of Table N1112.1.

 

TABLE N1112.1
Insultation and Fenestration Requirements by Componenta

 FENESTRATION

U-FACTORb

 SKYLIGHTb

U-FACTOR

 GLAZE

FENESTRATION

SHGCb,c

 CEILING 

R-VALUE

WOOD

FRAME WALL

R-VALUE 

 MASS WALL

R-VALUEg

FLOOR

R-VALUE 

 BASEMENTc

WALL R-VALUE

& DEPTH

SLABd

R-VALUE &

DEPTH 

 CRAWL

SPACEc WALL

R-VALUE
 0.34  0.55  0.31  R-49  R-13  8/13  30

 R-10/11, 3ft

Below Grade

Line

  10,2 ft  10/13

 

  1. a.
    R-values are minimums.  U-factors and SHGC are maximums.  Where insulation is installed in a cavity that is less than the label or design thickness of the insulation, the installed R-value of the insulation shall be not 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.
  3. c.
    “10/11 means R-10 continuous insulation on the interior or exterior of the home or R-11 cavity insulation on the interior of the basement wall.
  4. d.
    R-5 insulation shall be provided under the full slab area of a heated slab in addition to the required slab edge insulation R-value for slabs, as indicated in the table.  The slab edge insulation for heated slabs shall not be required to extend below the slab.
  5. e.
    There are no SHGC requirements in the Marine Zone.
  6. f.
    Basement wall insulation shall not be required in warm-humid locations as defined by Figure N1101.10 and Table N1101.10.
  7. g.
    Mass walls shall be in accordance with Sections N1102.2.5.  The second R-value applies where more than half of the insulation is on the interior of the mass wall.

N1112.4 Equipment efficiency rating.  The buildings mechanical equipment shall meet or exceed the requirements in Table N1112.2

TABLE N1112.2   
   MINIMUM EQUIPMENT EFFICIENCY RATING BY COMPONENT
 Furnace Air Conditioner  Water Heater 
 80% 13 SEER   62%

 

N1112.5 Lighting equipment.  Not less than 100 percent of the permanently installed recessed can lights and keyless fixtures shall contain only high-efficiency lamps.

 

(History:  Ord. BC-3286 §80, 2020) 

Effective on: 1/1/1901