The provisions of this chapter regulate the exterior envelope, as well as the design, construction and selection of heating, ventilating and air-conditioning systems, lighting and piping insulation required for the purpose of effective conservation of energy within a building or structure governed by this code.

All conditioned spaces within residential buildings shall comply with Table N1101.1(1) and two additional measures from Table N1101.1(2).

Exceptions:

Application to existing buildings shall comply with Section N1101.2.
Application to additions shall comply with Section N1101.3.
Heated or cooled detached accessory structures that are not habitable shall meet the following envelope requirements without any additional measures: Walls: R-21/U-0.064; Roofs: R-38/U-0.027 (attic) or R-20 continuous insulation/U-0.048 (above deck); Windows: U-0.35; Opaque doors: U-0.70; Roll-up doors: U-0.50.

TABLE N1101.1(1)
PRESCRIPTIVE ENVELOPE REQUIREMENTS^a
BUILDING COMPONENT	STANDARD BASE CASE		LOG HOMES ONLY
BUILDING COMPONENT	Required Performance	Equiv. Value^b	Required Performance	Equiv. Value^b
Wall insulation—above grade	U-0.059^c	R-21 Intermediate^c	Note d	Note d
Wall insulation—below grade^e	C-0.063	R-15/R-21	C-0.063	R-15/R-21
Flat ceilings^f	U-0.021	R-49	U-0.020	R-49 A^h
Vaulted ceilings^g	U-0.033	R-30 Rafter or R-30A^g,h Scissor Truss	U-0.027	R-38A^h
Underfloors	U-0.033	R-30	U-0.033	R-30
Slab edge perimeter	F-0.520	R-15	F-0.520	R-15
Heated slab interiorⁱ	n/a	R-10	n/a	R-10
Windows^j	U-0.30	U-0.30	U-0.30	U-0.30
Window area limitation^{j, k}	n/a	n/a	n/a	n/a
Skylights^l	U-0.50	U-0.50	U-0.50	U-0.50
Exterior doors^m	U-0.20	U-0.20	U-0.54	U-0.54
Exterior doors with > 2.5 ft² glazingⁿ	U-0.40	U-0.40	U-0.40	U-0.40
Forced air duct insulation	n/a	R-8	n/a	R-8

For SI: 1 inch = 25.4 mm, 1 square foot = 0.0929 m², 1 degree = 0.0175 rad, n/a = not applicable.

As allowed in Section N1104.1, thermal performance of a component may be adjusted provided that overall heat loss does not exceed the total resulting from conformance to the required U-factor standards. Calculations to document equivalent heat loss shall be performed using the procedure and approved U-factors contained in Table N1104.1(1).
R-values used in this table are nominal for the insulation only in standard wood framed construction and not for the entire assembly.
Wall insulation requirements apply to all exterior wood framed, concrete or masonry walls that are above grade. This includes cripple walls and rim joist areas. Nominal compliance with R-21 insulation and Intermediate Framing (N1104.5.2) with insulated headers.
The wall component shall be a minimum solid log or timber wall thickness of 3.5 inches (90 mm).
Below-grade wood, concrete or masonry walls include all walls that are below grade and do not include those portions of such wall that extend more than 24 inches (609.6 mm) above grade. R-21 for insulation in framed cavity; R-15 continuous insulation.
Insulation levels for ceilings that have limited attic/rafter depth such as dormers, bay windows or similar architectural features totaling not more than 150 square feet (13.9 m²) in area may be reduced to not less than R-21. When reduced, the cavity shall be filled (except for required ventilation spaces). R-49 insulation installed to minimum 6-inches depth at top plate at exterior of structure to achieve U-factor.
Vaulted ceiling surface area exceeding 50 percent of the total heated space floor area shall have a U-factor no greater than U-0.026 (equivalent to R-38 rafter or scissor truss with R-38 advanced framing).
A = Advanced frame construction. See Section N1104.6.
Heated slab interior applies to concrete slab floors (both on and below grade) that incorporate a radiant heating system within the slab. Insulation shall be installed underneath the entire slab.
Sliding glass doors shall comply with window performance requirements. Windows exempt from testing in accordance with Section NF1111.2, Item 3 shall comply with window performance requirements if constructed with thermal break aluminum or wood, or vinyl, or fiberglass frames and double-pane glazing with low-emissivity coatings of 0.10 or less. Buildings designed to incorporate passive solar elements may include glazing with a U-factor greater than 0.35 by using Table N1104.1(1) to demonstrate equivalence to building envelope requirements.
Reduced window area may not be used as a trade-off criterion for thermal performance of any component.

Exception: Table N1101.1(2), Envelope Measure 6: calculation allows baseline case 15 percent of total wall area as window when design case utilizes window area of less than 15 percent.
Skylight area installed at 2 percent or less of total heated space floor area shall be deemed to satisfy this requirement with vinyl, wood or thermally broken aluminum frames and double-pane glazing with low-emissivity coatings. Skylight U-factor is tested in the 20-degree (0.35 rad) overhead plane in accordance with NFRC standards.
A maximum of 28 square feet (2.6 m²) of exterior door area per dwelling unit can have a U-factor of 0.54 or less.
Glazing that is either double pane with low-e coating on one surface, or triple pane shall be deemed to comply with this U-0.30 requirement.

TABLE N1101.1(2)
ADDITIONAL MEASURES
Envelope Enhancement Measures (Select One)	1	High efficiency walls
		Exterior walls—U-0.045/R-21 cavity insulation + R-5 continuous
	2	Upgraded features
		Exterior walls—U-0.057/R-23 intermediate or R-21 advanced, Framed floors—U-0.026/R-38, and Windows—U-0.28 (average UA)
	3	Upgraded features
		Exterior walls—U-0.055/R-23 intermediate or R-21 advanced, Flat ceilinge—U-0.017/R-60, and Framed floors—U-0.026/R-38
	4	Super Insulated Windows and Attic OR Framed Floors
		Windows—U-0.22 (Triple Pane Low-e), and Flat ceilinge—U-0.017/R-60 or Framed floors—U-0.026/R-38
	5	Air sealing home and ducts
		Mandatory air sealing of all wall coverings at top plate and air sealing checklist^f, and Mechanical whole-building ventilation system with rates meeting M1503 or ASHRAE 62.2, and All ducts and air handlers contained within building envelope^d or All ducts sealed with mastic^b
	6	High efficiency thermal envelope UA^g
		Proposed UA is 8% lower than the code UA
Conservation Measure (Select One)	A	High efficiency HVAC system^a
		Gas-fired furnace or boiler AFUE 94%, or Air source heat pump HSPF 9.5/15.0 SEER cooling, or Ground source heat pump COP 3.5 or Energy Star rated
	B	Ducted HVAC systems within conditioned space
		All ducts and air handlers contained within building envelope^d Cannot be combined with Measure 5
	C	Ductless heat pump
		Ductless heat pump HSPF 10.0 in primary zone of dwelling
	D	High efficiency water heater^c
		Natural gas/propane water heater with UEF 0.85 OR Electric heat pump water heater Tier 1 Northern Climate Specification Product

For SI: 1 square foot = 0.093 m², 1 watt per square foot = 10.8 W/m².

Appliances located within the building thermal envelope shall have sealed combustion air installed. Combustion air shall be ducted directly from the outdoors.
All duct joints and seams sealed with listed mastic; tape is only allowed at appliance or equipment connections (for service and replacement). Meet sealing criteria of Performance Tested Comfort Systems program administered by the Bonneville Power Administration (BPA).
Residential water heaters less than 55 gallon storage volume.
A total of 5 percent of an HVAC system’s ductwork shall be permitted to be located outside of the conditioned space. Ducts located outside the conditioned space shall have insulation installed as required in this code.
The maximum vaulted ceiling surface area shall not be greater than 50 percent of the total heated space floor area unless vaulted area has a U-factor no greater than U-0.026.
Continuous air barrier. Additional requirement for sealing of all interior vertical wall covering to top plate framing. Sealing with foam gasket, caulk or other approved sealant listed for sealing wall covering material to structural material (example: gypsum board to wood stud framing).
Table N1104.1(1) Standard base case design, Code UA shall be at least 8 percent less than the Proposed UA. Buildings with fenestration less than 15 percent of the total vertical wall area may adjust the Code UA to have 15 percent of the wall area as fenestration.

TABLE N1104.1(1)
RESIDENTIAL THERMAL PERFORMANCE CALCULATIONS
BUILDING COMPONENTS^b	STANDARD BASE CASE^a			PROPOSED ALTERNATIVE
BUILDING COMPONENTS^b	Areas^c	U-factor	Areas × U	R-value^d	Areas^c	U-factor^e	Areas x U
Flat ceilings Vaulted ceilings^f Conventional wood-framed walls Underfloor Slab edge Below grade walls		0.021 0.033 0.059 0.033 F=0.52^g C=0.063^g
Windows Skylights		0.30 0.50
Exterior doors^h Doors with > 2.5 ft² glazin^g		0.2 0.4
CODE UA =				Proposed UAⁱ =

Base path 1 represents Standard Base Case from Table N1101.1(1). U-factors shall be adjusted to match selected Envelope Measure [Table N1101.1(2)].
Performance trade-offs are limited to those listed in column 1. Heat plant efficiency, duct insulation levels, passive and active solar heating, air infiltration and similar measures including those not regulated by code may not be considered in this method of calculation.
Areas from plan take-offs. All areas must be the same for both Standard Base Case and Proposed Alternate. The vaulted ceiling surface area for Standard Base Case must be the actual surface area from the plan take-off not to exceed 50 percent of the total heated space floor area. Any roof areas in excess of 50 percent for Base Case must be entered at U-0.021 (R-49) with “Flat Ceilings” area.
Minimum Component Requirements in so far as practicable: Walls R-15/U-0.080; Floors R-21/U-0.047; Flat Ceilings R-38/U-0.031; Vaults R-21/U-0.055; Below-Grade Wood, Concrete or Masonry Walls R-15/C-0.069; Slab Edge R-10/F-0.52; Duct Insulation R-8. R-values used in this table are nominal, for the insulation only and not for the entire assembly. Window and skylight U-values shall not exceed 0.65 (CL65). A single door not to exceed 28 square feet (2.6 m²) per dwelling unit is permitted to be excluded from the thermal performance calculations. All other Door-values shall not exceed 0.54 (Nominal R-2).
U-factors for wood frame ceilings, walls and floor assemblies shall be as specified in Table N1104.1(2). U-factors for other assemblies, which include steel framing, brick or other masonry, stucco, etc., shall be calculated using ASHRAE Handbook of Fundamentals procedures.
Vaulted area, unless insulated to R-38, 0.027, may not exceed 50 percent of the total heated space floor area.
F = The heat loss coefficient, Btu/h/ft²/°F per foot of perimeter. C = the heat loss coefficient Btu/h/ft²-°F per square foot of underground wall.
A maximum of 28 square feet (2.6 m²) of exterior door area per dwelling unit can have a U-factor of 0.54 or less. Default U-factor for an unglazed wood door is 0.54.
Proposed UA must be less than or equal to CODE UA. For compliance with Envelope Measure 6, the Proposed UA must be a minimum of 8 percent less than the CODE UA.

TABLE N1104.1(2)
APPROVED DEFAULT U-FACTORS
FLAT CEILINGS^a			EXTERIOR WALLS^a
Insulation	Type	U-Factor	Insulation	Insulation Sheathing	Framing	U-Factor
R-38	Conventional framing	0.027	R-15	0	Conventional framing	0.083
R-38	Advanced framing^c	0.026	R-15	0	Intermediate framing^b	0.078
R-49	Conventional framing	0.021	R-19	0	Conventional framing	0.067
R-49	Advanced framing^c	0.020	R-19	0	'Intermediate framing^b	0.063
R-60	Conventional framing	0.017	R-19	0	Advance framing^d	0.062
VAULTED CEILINGS ^a
Insulation	Type	U-Factor	R-21	0	Conventional framing	0.063
R-21	Rafter framings	0.050	R-21	0	Intermediate framing ^b	0.059
R-30	Rafter framing	0.032	R-21	0	Advance framing^d	0.057
R-38	Rafter framing	0.026
			R-13	3.5^e	Conventional framing	0.065
R-21	Scissors truss	0.052	R-13	5^e	Conventional framing	0.059
R-30	Scissors truss	0.034	R-13	7^e	Conventional framing	0.053
R-38	Scissors truss	0.027	R-13	3.5^e	Advance framing^d	0.062
R-49	Scissors truss	0.021	R-13	5^e	Advance framing^d	0.056
			R-13	7^e	Advance framing^d	0.050
R-30	Advance scissors truss^c	0.032
R-38	Advance scissors truss^c	0.026	R-15	3.5^e	Conventional framing	0.062
R-49	Advance scissors truss^c	0.020	R-15	5^e	Conventional framing	0.056
EPS FOAM CORE PANEL VAULTED CEILINGS			R-15	7e	Conventional framing	0.050
Insulation	Type	U-Factor	R-15	3.5^e	Advance framing^d	0.057
R-29	8¼″ EPS foam core panel	0.034	R-15	5^e	Advance framing^d	0.052
R-37	10¼″ EPS foam core panel	0.027	R-15	7^e	Advance framing^d	0.047
R-44	12¼″ EPS foam core panel	0.023
FLOORS^a			R-19	3.5^e	Conventional framing	0.052
Insulation	Type	U-Factor	R-19	5^e	Conventional framing	0.048
R-21	Underfloor	0.046	R-19	7^e	Conventional framing	0.044
R-25	Underfloor	0.039	R-19	3.5^e	Advance framing^d	0.049
R-30	Underfloor	0.033	R-19	5^e	Advance framing^d	0.046
R-38	Underfloor	0.026	R-19	7^e	Advance framing^d	0.042
SLAB-ON-GRADE
Insulation	Type	F-Factor^f	R-21	3.5^e	Conventional framing	0.049
R-10	Slab edge	0.54	R-21	5^e	Conventional framing	0.045
R-15	Slab edge	0.52	R-21	7^e	Conventional framing	0.041
EPS FOAM CORE PANEL EXTERIOR WALLS			R-21	3.5^e	Advance framing^d	0.046
Insulation	Type	U-Factor	R-21	5^e	Advance framing^d	0.043
R-14.88	4½″ EPS foam core panel	0.059	R-21	7^e	Advance framing^d	0.039
R-22.58	6¼″ EPS foam core panel	0.040
R-29.31	8¼″ EPS foam core panel	0.031
BELOW GRADE WALLS
Insulation	Type	C-Factor
R-10 c.i.	R-10 continuous insulation	0.085
R-15 c.i.	R-15 continuous insulation	0.063
R-13	R-13 cavity and air space	0.080
R-21	R-21 cavity and air space	0.063

For SI: 1 inch = 25.4 mm.

U-factors are for wood frame construction. U-factors for other assemblies which include steel framing, brick or other masonry, stucco, etc., shall be calculated using standard ASHRAE Handbook of Fundamentals procedures.
Intermediate framing consists of wall studs placed at a minimum 16 inches (406 mm) on center with insulated headers. Voids in headers shall be insulated with rigid insulation having a minimum R-value of 4 per 1-inch (25.4 mm) (W/m³-k) thickness.
Advanced framing construction for ceilings as defined in Section N1104.6.
Advanced framing construction for walls as defined in Section N1104.5.1
Insulation sheathing shall be rigid insulation material, installed continuously over entire exterior or interior of wall (excluding partition walls).
F-Factor is heat loss coefficient in Btu/h/°F per lineal foot of concrete slab perimeter.

N1101.2 Application to existing buildings

Alteration and repairs, historic buildings and change of use or occupancy to buildings, structures or portions thereof shall comply with the requirements in Sections N1101.2.1 through N1101.2.3.

TABLE N1101.2
EXISTING BUILDING COMPONENT REQUIREMENTS
BUILDING COMPONENTS	REQUIRED PERFORMANCE	EQUIV. VALUE
Wall insulation	U-0.083	R-15
Flat ceiling	U-0.025	R-49
Vaulted ceiling > 10 inches nominal rafter depth	U-0.040	R-25
Vaulted ceiling > 8 inches nominal rafter depth	U-0.047	R-21
Underfloor > 10 inches nominal joist depth	U-0.028	R-30
Underfloor > 8 inches nominal joist depth	U-0.039	R-25
Slab edge perimeter	F-0.52	R-15
Windows	U-0.30	U-0.30
Skylights	U-0.60	U-0.60
Exterior doors	U-0.20	R-5
Exterior doors with > 2.5 ft² glazing	U-0.40	R-2.5
Forced air ducts	n/a	R-8

For SI: inch = 25.4 mm, 1 square foot = 0.0929 m².

N1101.2.1 Alteration and repair

Alterations and repairs affecting energy conservation measures shall conform to the requirements specified in this chapter.

Alterations or repairs which affect components of existing conditioned spaces regulated in this chapter, those components shall comply with this chapter.

Exception: The minimum component requirements as specified in Table N1101.2 may be used to the maximum extent practical.

N1101.2.2 Historic buildings

The building official may modify the specific requirements of this chapter for historic buildings and require in lieu thereof alternative requirements that will result in a reasonable degree of energy efficiency. This modification may be allowed for those buildings specifically designated as historically significant by the state historic preservation office(r) or by official action of a local government.

N1101.2.3 Change of occupancy or use

Definition of “Change of use” for purposes of Section N1101.2.3 is a change of use in an existing residential building and shall include any of the following: any unconditioned spaces such as an attached garage, basement, porch, or canopy that are to become conditioned spaces; any unconditioned, inhabitable space that is to become conditioned space, such as a large attic.

N1101.2.3.1 Change of use

A building that changes use, without any changes to the components regulated in this chapter, is required to comply with Table N1101.2 to the greatest extent practical. Changes of use that are greater than 30 percent of the existing building heated floor area or more than 400 square feet (37 m²) in area, whichever is less, shall be required to select one measure from Table N1101.3.

TABLE N1101.3
SMALL ADDITION ADDITIONAL MEASURES (Select one)
1	Increase the ceiling insulation of the existing portion of the home as specified in Table N1101.2.
2	Replace all existing single-pane wood or aluminum windows to the U-factor as specified in Table N1101.2
3	Insulate the floor system as specified in Table N1101.2 & install 100 percent of permanently installed lighting fixtures as CFL, LED, or linear fluorescent or a min. efficacy of 40 lumens per watt as specified in Section N1107.2.
4	Test the entire dwelling with a blower door and exhibit no more than 6.0 air changes per hour @ 50 Pascals.
5	Seal and performance test the duct system.
6	Replace existing 78 percent AFUE or less gas furnace with a 92 percent AFUE or greater system.
7	Replace existing electric radiant space heaters with a ductless mini split system with a minimum HSPF of 10.0.
8	Replace existing electric forced air furnace with an air source heat pump with a minimum HSPF of 9.5.
9	Replace existing water heater with a water heater meeting Conservation Measure D [Table N1101.1(2)]

N1101.2.3.2 Change of occupancy

Alteration and repair of conditioned nonresidential buildings, such as a small church or school, that are changing occupancy to residential shall use Table N1101.2 to the greatest extent practical and select one measure from Table N1101.1(2), or one measure from Table N1101.3.

Exception: The minimum component requirements shall be disregarded when thermal performance calculations are completed for change of use to Group R occupancy, when such calculations demonstrate similar performance to the requirements of Table N1101.2.

N1101.3 Additions

Additions to existing buildings or structures may be made without making the entire building or structure comply if the new additions comply with the requirements of this chapter.

N1101.3.1 Large additions

Additions that are equal to or more than 40 percent of the existing building heated floor area or 600 square feet (55 m²) in area, whichever is less, shall be required to comply with Table N1101.1(2).

N1101.3.2 Small additions

Additions that are less than 40 percent of the existing building heated floor area or less than 600 square feet (55 m²) in area, whichever is less, shall be required to select one measure from Table N1101.1(2) or comply with Table N1101.3.

Exception: Additions that are less than 15 percent of existing building heated floor area or 200 square feet (18.58 m²) in area, whichever is less, shall not be required to comply with Table N1101.1(2) or Table N1101.3.

N1101.4 Information on plans and specifications

Plans and specifications shall show in sufficient detail all pertinent data and features of the building and the equipment and systems as herein governed, including, but not limited to: exterior envelope component materials; R-values of insulating materials; HVAC equipment efficiency performance and system controls, lighting and other pertinent data to indicate conformance with the requirements of this chapter.

Section N1102 DEFINITIONS

AFUE (ANNUAL FUEL UTILIZATION EFFICIENCY). The energy output divided by the energy input, calculated on an annual basis and including part load and cycling effects. AFUE ratings shall be determined using the U.S. Department of Energy test procedures (10 CFR Part 430).

AUTOMATIC. Self-acting, operating by its own mechanism when actuated by some impersonal influence, such as a change in current strength, pressure, temperature or mechanical configuration. (See also “Manual.”)

BASEMENT WALL. The opaque portion of walls which encloses a basement and is partially or totally below grade walls.

BELOW GRADE WALLS. The walls or the portion of walls entirely below the finished grade or which extend 2 feet (610 mm) or less above the finished grade.

BTU (British Thermal Unit). The amount of heat required to raise the temperature of 1 pound (0.454 kg) of water (about 1 pint) from 59°F to 60°F (15°C to 16°C).

BUILDING ENVELOPE. That element of a building which encloses conditioned spaces through which thermal energy may be transmitted to or from the exterior or to or from unconditioned spaces.

C (Thermal Conductance). See “Thermal conductance.”

CONDITIONED SPACE. A space within the building, separated from unconditioned space by the exterior envelope, which by introduction of conditioned air, by heated and/or cooled surfaces, or by air or heat transfer from directly conditioned spaces is maintained at temperatures of 55°F (13°C) or higher for heating and/or 85°F (29.4°C) or below for cooling. (Enclosed corridors between conditioned spaces shall be considered as conditioned space. Spaces where temperatures fall between this range by virtue of ambient conditions shall not be considered as conditioned space.)

COOLED SPACE. A space within a building provided with a mechanical cooling supply.

EXTERIOR DOOR. A permanently installed operable barrier by which an entry is closed and opened. Exterior doors include doors between conditioned and unconditioned spaces, such as a door between a kitchen and garage.

EXTERIOR ENVELOPE. See “Building envelope.”

EXTERIOR WALL. Any member, or group of members, which defines the exterior boundaries of the conditioned space and which has a slope of 60 degrees (1.05 rad) or greater with the horizontal plane.

EXTERIOR WINDOW. An opening, especially in the wall of a building, for admission of light or air that is usually closed by casement or sashes containing transparent material (such as glass) and in some cases capable of being opened and shut. All areas, including frames, in the shell of a conditioned space that let in natural light, including skylights, sliding glass doors, glass block walls and the glazed portions of the doors.

When calculating the energy performance of the exterior envelope, the area of the window shall be the total area of glazing measured using the rough opening dimensions, and including the glass, sash and frame.

FENESTRATION. Windows and doors in the exterior envelope. See the definitions for “Exterior door” and “Exterior window.”

FLOOR AREA. The area included within the surrounding exterior walls of a building or portion thereof, exclusive courts. The floor area of a building or portion thereof, not provided with surrounding exterior walls shall be the usable area under the horizontal projection of the roof or floor above.

GLAZING. All areas including frames in the shell of a conditioned space that let in natural light, including windows, clerestories, skylights, sliding glass doors, glass block walls and the glazed portion of doors.

GROSS AREA OF EXTERIOR WALLS. Consists of wall areas, as measured on the exterior, including foundation walls above grade; peripheral edges of floors; window areas, including sash; and door areas, where such surfaces are exposed to outdoor air and enclose a heated or mechanically cooled space.

HEATED SPACE. A space within a building served by a mechanical, electrical or combustion source of heat. Spaces within a basement shall be defined as heated when any of the following apply: the space is finished, or has heating registers or contains heating devices.

HIGH-EFFICACY LAMPS. Compact fluorescent lamps, T-8 or smaller diameter linear fluorescent lamps, LED lamps, fixture-integrated illumination devices, or lamps with a minimum efficacy of:

60 lumens per watt for lamps over 40 watts.
50 lumens per watt for lamps over 15 watts to 40 watts.
40 lumens per watt for lamps 15 watts or less.

HSPF (HEATING SEASONAL PERFORMANCE FACTOR). The total heating output of a heat pump during its normal annual usage period for heating divided by the total electric power input in watt-hours during the same period.

HUMIDISTAT. An instrument which measures changes in humidity and controls a device or devices to maintain a desired humidity.

HVAC (HEATING, VENTILATING AND AIR-CONDITIONING) SYSTEM. Refers to the equipment, distribution network, and terminals that provide either collectively or individually the processes of heating, ventilating, and/or airconditioning processes to a building.

K (THERMAL CONDUCTIVITY). See “Thermal conductivity.”

MANUAL (nonautomatic). Action requires human intervention as the basis for control (see “Automatic”).

OTHER BUILDINGS. All buildings and structures, or portions thereof, that are not defined as residential buildings (see “Residential buildings”).

PERM RATING (DRY CUP). The measure of the ability of a material of specific thickness to transmit moisture in terms of the amount of moisture transmitted per unit time for a specified area and differential pressure. Dry cup perm rating is expressed in grains/hr/ft², inches of Hg. Permeance may be measured by using ASTM E96-72 or other approved dry cup method. The closer the dry cup perm rating approaches zero, the better the vapor retarder. Permeability is defined as the permeance of a material for specified unit length (perm/in).

R (THERMAL RESISTANCE). See “Thermal resistance.”

Rt (THERMAL RESISTANCE TOTAL). See “Thermal resistance total.”

RESIDENTIAL BUILDINGS. Buildings and structures, or portions thereof, housing Group R occupancies which are three stories or less in height.

THERMAL CONDUCTANCE (C). The constant time rate of heat flow through a unit area of a body induced by a unit temperature difference between the surfaces [Btu/(h • ft² • °F)]. It is the reciprocal of thermal resistance (see “Thermal resistance”).

THERMAL CONDUCTIVITY (K). The rate of heat flow through 1 square foot (0.0929 m²) of a homogeneous material 1-inch (25.4 mm) thick when there is a temperature difference of 1°F (-17.2°C) between the opposite faces of the material, expressed as Btu/h per square foot per °F temperature difference. Thermal conductivity is similar to thermal conductance (C), except thermal conductance applies to the actual thickness of the material.

THERMAL RESISTANCE (R). The measure of the resistance of a material or building component to the passage of heat, has the value of (hr • ft² • °F)/Btu, and is the reciprocal of thermal conductance.

THERMAL RESISTANCE TOTAL (Rt). The sum of the resistance for all of the individual components of the assembly, including framing members, multiple layer connections, insulation and air films expressed in (°F • ft² • Btu/h).

THERMAL TRANSMITTANCE (U). The coefficient of heat transfer. It is the time rate of heat flow per unit area under steady state conditions from the fluid on the warm side of the barrier to the fluid on the cold side, per unit temperature difference between the two fluids, Btu/(hr • ft² • °F).

THERMOSTAT. An instrument that measures changes in temperature and controls a device or devices to maintain a desired temperature.

TOTAL SOLAR RESOURCE FRACTION. The fraction of usable solar energy that is received by the solar panel/collector throughout the year. This accounts for the impacts due to external shading, collector tilt and collector orientation.

U (THERMAL TRANSMITTANCE). See “Thermal transmittance.”

VAULTED CEILING. A residential building is a ceiling with a minimum slope of 2 in 12.

WINDOW. See “Exterior window.”

ZONE. A space or group of spaces within a building with heating or cooling requirements sufficiently similar so that comfort conditions can be maintained throughout by a single controlling device.

Section N1103 ALTERNATIVE SYSTEMS

Alternative designs may be approved by the building official when it can be demonstrated that the proposed annual energy consumption will not exceed that of a similar building with similar forms of energy requirements designed in accordance with the provisions of this chapter. The only allowed trade-offs in this analysis are between building envelope components.

Proposed alternative designs submitted as requests for exception to the standard design criteria must be accompanied by an energy analysis prepared in accordance with criteria specified in Part II, Alternative Systems Analysis.

N1103.1 Design parameters

For calculations under this section, the following design parameters shall apply:

The outside temperature shall be taken from the 99-percent winter temperature values and the 1-percent summer temperature values listed in ASHRAE Handbook of Fundamentals. For areas not listed, the designer should obtain the most reliable design temperatures available. Selected values are subject to approval of the building official.

Section N1104 EXTERIOR ENVELOPE REQUIREMENTS

N1104.1 General

This section provides, minimum requirements for exterior envelope construction.

Exterior building envelope shall comply with Table N1101.1(1) or may be demonstrated using Table N1104.1(1). The requirements specified in Table N1101.1(2) shall apply to both Tables N1101.1(1) and N1104.1(1).

Buildings designed to incorporate passive solar elements may use Table N1104.1(1) to demonstrate building envelope requirements in this code, in addition to requirements specified in Table N1101.1(2).

N1104.2 Insulation materials

Insulation materials shall be installed in accordance with manufacturer’s listing and installation instructions and this code. Insulation R-values shall be specified as required in 16 CFR Ch. I (1-1-91 Edition) Part 460—Labeling and Advertising of Home Insulation. Cellulose insulation shall conform to Interim Safety Standard for Cellulose Insulation (16 CFR Part 1209) issued by the Consumer Product Safety Commission July 6, 1979 (44FR 39938). Foam plastic shall be as specified in Section R316.

N1104.2.1 Insulation clearance restriction

Blown, poured, batt and spray-on type insulation applied from above the ceiling level shall be limited in vented attic spaces where roof slope is 4 units vertical in 12 units horizontal (33.3-percent slope) or greater and there is at least 44 inches (1118 mm) of headroom at the roof ridge. (Clear headroom is defined as the distance from the top of the bottom chord of the truss or ceiling joists to the underside of the roof sheathing.) Netted or other applications that allow for verification of insulation application shall be allowed for low-slope roofs.

N1104.2.2 Batt-type insulation

Batt-type insulation shall be installed flush against the warm side of the cavity insofar as practicable.

N1104.2.3 Insulation protection

Insulation exposed to the exterior shall be protected from physical and solar damage.

N1104.2.4 Clearances

Recessed light fixtures shall be IC-labeled for direct insulation contact.

Thermal insulation shall not be installed within 3 inches (76 mm) of any metal chimney or gas vent that is not listed for insulation clearances.

A permanent sleeve of fine wire mesh screen, sheet metal or other noncombustible material shall be installed to maintain the required clearances.

N1104.2.5 Baffles

Baffles of a durable rigid material shall be provided to prevent obstruction of vent openings and to deflect incoming air above the surface of porous insulation so as to prevent wind-washing and blowing of loose material. Thermal insulation shall not be installed in a manner that would obstruct openings required for attic ventilation.

N1104.2.6 Air barriers

An air barrier shall be provided on every vertical portion of air-permeable insulation and on the warm side of horizontal, air-permeable insulation.

Exception: Unvented attics, continuous insulation walls and similar conditions where an impermeable insulation layer forms an air barrier.

N1104.2.7 Below grade exterior insulation

Below grade exterior insulation shall meet the following conditions:

The insulation shall be a material that is approved for below grade applications in wet environments.
Insulation shall be installed from the top of the footing to the top of the concrete basement wall.
Insulation shall be adequately protected from the elements (ultraviolet and mechanical) in accordance with manufacturer’s specifications.
The top of the insulation shall be installed in a manner to allow water run-off and prevent pooling.

N1104.2.8 Recessed lighting fixtures

Recessed lighting fixtures installed within the building envelope shall meet one of the following requirements.

Type IC-rated, manufactured with no penetrations between the inside of the recessed fixture and ceiling cavity, and the annular space between the ceiling cutout and lighting fixture shall be sealed.
Type IC-rated in accordance with ASTM E283 with no more than 2.0 cubic feet per minute (cfm) (0.944 L/s) air movement from the conditioned space to the ceiling cavity at 1.57 psi pressure (75 Pa) difference shall be labeled and the annular space between the ceiling cutout and lighting fixture shall be sealed.
Type IC-rated installed inside a sealed box constructed from a minimum 0.5-inch-thick (12.7 mm) gypsum wallboard or constructed from a preformed polymeric vapor retarder or other air-tight assembly manufactured for this purpose.

N1104.2.9 Doors and pull-down stairs to unconditioned spaces

Service doors between unconditioned and conditioned spaces shall meet the thermal requirements of Sections N1104.2.9.1 and N1104.2.9.2.

N1104.2.9.1 Vertical doors

U-factors for vertical doors providing access from conditioned to unconditioned spaces shall comply with the exterior door provisions of Table N1101.1(1).

N1104.2.9.2 Pull-down stairs

Horizontal pull-down stair-type access hatches in ceiling assemblies that provide access from conditioned to unconditioned spaces shall have a maximum average U-factor of U-0.10 or an R-value of not less than R-10, have a net area of the framed opening not exceeding 13.5 square feet, and have the perimeter of the hatch weather-stripped.

N1104.3 Exterior doors

Doors shall be tested according to the requirements of Section N1104.4. When calculating the energy performance of the exterior envelope, the area of doors shall be the actual unit size.

Exceptions:

Unglazed doors that are not tested according to the requirements of Section N1104.4 shall be assigned a default U-value of 0.54.
Sliding glass doors and swinging glass doors shall meet the specifications for windows and shall be treated as such.
Doors that incorporate glazed areas more than 2.5 square feet (0.23 m²) in area shall be considered exterior doors with greater than or equal to 2.5 square feet (0.23 m²) glazing. Doors shall meet the air leakage requirements of Section N1104.8.

N1104.4 Windows

All windows installed in Oregon shall meet the requirements of Part III, Fenestration Standard.

Decorative or unique architectural feature glazing not exceeding 1 percent of the heated space floor area is exempt from thermal performance requirements and does not need to be included in Table N1104.1(1) calculations.
Glass block assemblies may use a U-factor of 0.51.
The U-factor for windows may be a weighted average of total window area when all other building envelope measures are in compliance with performance requirements specified in this code. This calculation shall be provided to the building official and the windows that are less than required for prescriptive compliance shall be identified on the plans.

N1104.4.1 Thermal performance labeling

Labels shall be either:

National Fenestration Rating Council (NFRC) certified product; or
State-approved for windows produced in low volume. All windows shall have labeling:
1. That is imprinted, not handwritten,
2. Facing the interior of the room,
Attached to the window until the building inspector inspects and verifies the labeling, and
List the U-factor.

Exceptions:

Labeling is not required for decorative or unique architectural feature glazing not exceeding 1 percent of the heated space floor area.
Portions of labels for windows produced in low volume may be handwritten.

N1104.4.2 Combined products

When different window types are combined, mulled together by the manufacturer or manufactured to fit a framed rough opening, a single label may be used.

Exception: A solarium shall have one label providing a description of each of the glazed surfaces, such as the front, overhead and each side.

N1104.4.3 Air leakage requirements

Windows shall comply with the air leakage requirements of Section N1104.8.

Exception: Site-built windows.

N1104.4.4 Alterations

New windows shall have a maximum U-factor as required by Table N1101.1(1).

Exceptions:

Decorative or unique architectural feature glazing not exceeding 1 percent of the heated space floor area may be exempt from thermal performance requirements and Table N1104.1(1) calculations.
Where necessary to retain architectural consistency with remaining windows in the building, new windows shall have a maximum U-value of 0.65.

N1104.5 Walls

N1104.5.1 Advanced framing for walls

Advanced framing for walls is an optional construction method. Advanced framing, when used to qualify a design under the requirements of Table N1104.1(1), shall meet the following requirements:

Walls. Walls shall be framed with 2× studs at 24 inches (610 mm) on center and shall include the following, as detailed in Items 2 and 3.
Corners and intersections. Exterior wall and ceiling corners shall be fully insulated through the use of three-stud corners configured to allow full insulation into the corner, or two-stud corners and drywall backup clips or other approved technique. Intersections of interior partition walls with exterior walls shall be fully insulated through the use of single backer boards, mid-height blocking with drywall clips or other approved technique.
Headers. Voids in headers 1 inch (25.4 mm) or greater in thickness shall be insulated with rigid insulation that has a value of R-4 per 1 inch (25.4 mm) or greater. Nonstructural headers (such as in gable-end walls) can be eliminated and replaced with insulation to achieve equivalent levels as the surrounding area.

N1104.5.2 Intermediate framing for walls

Intermediate framing for walls is an optional construction method. Intermediate framing, when used to achieve improved wall performance under the requirements of Table 1101.1(1) or Table N1104.1(2), shall meet the following requirements:

Walls. Walls shall be framed with 2× studs at 16 inches (610 mm) on center and shall include the following, as detailed in Items 2 and 3.
Corners and intersections. Exterior wall and ceiling corners shall be fully insulated through the use of three-stud corners configured to allow full insulation into the corner, or two-stud corners and drywall backup clips or other approved technique. Intersections of interior partition walls with exterior walls shall be fully insulated through the use of single backer boards, mid-height blocking with drywall clips or other approved technique.
Headers. Voids in headers 1 inch (25.4 mm) or greater in thickness shall be insulated with rigid insulation that has a value of R-4 or greater per 1 inch (25.4 mm) thickness. Nonstructural headers (such as in gable-end walls) can be eliminated and replaced with insulation to achieve equivalent levels as the surrounding area.

N1104.5.3 Below-grade walls

Walls enclosing heated spaces below grade shall be insulated from the bottom of the above-grade sub-floor downward to the top of the below-grade finished floor.

N1104.6 Roof/ceiling: advanced framing for ceilings

Advanced framing for ceilings is an optional construction method. Advanced framing, when used to qualify a design under the requirements of Section N1104.1, shall meet the following requirements:

Framing techniques shall be used in attics and ceilings to provide full insulating value to the outside of exterior walls. This may be accomplished through the use of extra-depth or oversized trusses, double rafters, special insulation components installed at the edge of the wall, or other approved combinations of framing and insulation. The entire surface of the exterior ceiling shall be insulated to the required value including attic hatches, structural members, electrical fixtures (where allowed by the code) and plumbing penetrations.

N1104.7 Slab-on-grade floors

For slab-on-grade floors, the perimeter of the floor shall be insulated.

The insulation shall extend downward from the top of the slab for a minimum of 24 inches (610 mm) or downward to the bottom of the slab, then horizontally beneath the slab for a minimum total distance of 24 inches (610 mm).

Exception: For monolithic slabs, the insulation shall extend downward from the top of the slab to the bottom of the thickened edge.

N1104.7.1 Slab-on-grade floors with hydronic heat

For slab-on-grade floors that incorporate hydronic heating, in addition to perimeter insulation, the entire underside of slab shall be insulated to R-10.

N1104.8 Air leakage

The requirements of this subsection shall apply only to those locations separating outdoor ambient conditions from interior spaces that are heated or mechanically cooled and are not applicable to separation of interior spaces from each other. Compliance with the criteria for air leakage shall be determined by tests based on applicable engineering principles.

N1104.8.1 Acceptance criteria

Where specified, compliance with air infiltration rates for all exterior windows, swinging doors and sliding glass doors shall be certified using ASTM E283 “Standard Test Methods for Rate of Air Leakage through Exterior Windows, Curtain Walls and Doors Under Specified Pressure Differences Across the Specimen.” Tests shall be conducted at a differential pressure of 1.57 pounds per square foot (75 Pa) [equivalent to 25 mph (40 km/h) wind condition].

Windows—0.37 cubic feet per minute (cfm) per foot (0.17 L/s per m) of sash crack.
Swinging doors—0.37 cfm per square foot (0.17 L/s per m²) of door area.
Sliding doors—0.37 cfm per square foot (0.17 L/s per m²) of door area.

N1104.8.2 Sealing required

Exterior joints around windows and door frames, between wall cavities and window or door frames, between wall and foundation, between wall and roof, between wall panels, at penetrations or utility services through walls, floors and roofs and all other openings in the exterior envelope shall be sealed in a manner approved by the building official.

N1104.9 Moisture control

To ensure the effectiveness of insulation materials and reduce the hazard of decay and other degradation due to condensation within the structure, moisture- control measures shall be included in all buildings and structures or portions thereof regulated by this chapter.

N1104.9.1 Vapor retarders

A Class I vapor retarder shall be installed on the warm side (in winter) of all insulation.

Exceptions:

When insulation is installed in ceilings and ventilation is provided as specified in Section R806, a vapor retarder need not be installed.
Below grade walls are not required to have a vapor retarder.
Slab-on-grade floors need not have a warm-side vapor retarder.

N1104.9.2 Ground cover

A ground cover shall be installed in the crawl space for both new and existing buildings when insulation is installed. Ground cover shall be installed in accordance with Chapter 4.

Section N1105 HEATING, VENTILATING AND AIR-CONDITIONING SYSTEMS

N1105.1 General

This section provides minimum requirements for heating, ventilating and air-conditioning systems.

N1105.2 Insulation of ducts

All new duct systems, or new portions thereof, exposed to unconditioned spaces shall be insulated according to Table N1101.1(1).

Exception: The replacement or addition of a furnace, air conditioner or heat pump shall not require existing ducts to be insulated to current code.

N1105.3 HVAC controls

All heating, ventilating and air-conditioning systems shall be provided controls as specified herein.

N1105.3.1 Temperature

Each heating, ventilating and air-conditioning system shall be provided with at least one thermostat for the regulation of temperature. Each thermostat shall be capable of being set from 55°F to 75°F (13°C to 24°C) where used to control heating only and from 70°F to 85°F (21°C to 29°C) where used to control cooling only. Where used to control both heating and cooling, it shall be capable of being set from 55°F to 85°F (13°C to 29°C) and shall be capable of operating the system heating and cooling in sequence. It shall be capable of providing a temperature range of at least 5°F (-15°C) within which the supply of heating and cooling energy to the zone is shut off or reduced to a minimum.

N1105.3.2 Humidity

If a heating, ventilating and air-conditioning system is equipped with a means for adding moisture to maintain specific selected relative humidity in spaces or zones, a humidistat shall be provided. This device shall be capable of being set to prevent new energy from being used to produce space relative humidity above 30 percent. Where a humidistat is used in a heating, ventilating and air-conditioning system for controlling moisture removal to maintain specific selected relative humidity in spaces or zones, it shall be capable of being set to prevent new energy from being used to produce a space-relative humidity below 60 percent.

N1105.3.3 Temperature zoning

Each separate heating, ventilating and air-conditioning system shall be provided at least one thermostat for regulation of space temperature. In addition, a readily accessible manual or automatic means shall be provided to partially restrict or shut off the heating or cooling input to each zone or floor, excluding unheated or noncooled basements and garages.

N1105.3.4 Setback and shutoff

The thermostat, or an alternative means such as switch or clock, shall provide a readily accessible manual or automatic means for reducing the energy required for heating and cooling during periods of nonuse or reduced need.

Exceptions:

Where it can be shown that setback or shutdown will not result in a decrease in overall building energy.
Equipment with full load demand of 2 kilowatt (6.826 Btu/h) or less may be controlled by readily accessible off-hour controls.

Lowering thermostat set points to reduce energy consumption of heating system shall not cause energy to be expended to reach the reduced setting.

N1105.3.4.1 Heat pump controls

All heat pump system thermostats shall be capable of manual setback and limiting the use of supplemental heat during warm-up periods.

N1105.3.4.1.1 Outdoor thermostat required

An outdoor thermostat or factory installed temperature sensor with electronic controls shall be used to lock out supplemental heat based on outdoor air temperature. The lock-out temperature shall be set at 400°F (40°C). There shall be no compressor lock-out temperature.

N1105.4 Outside combustion air

See Section R1006 for required outside combustion air for masonry fireplaces, factory- built fireplace(s) and factory-built stoves.

N1105.5 Equipment performance requirements

N1105.5.1 Economizer cooling

Each fan system with mechanical cooling shall have an air economizer system capable of modulating outside air and return dampers to provide up to 100 percent of the design supply air quantity as outdoor air.

Exceptions:

Cooling equipment rated at less than 54,000 Btu/h (15827 W) total cooling capacity.
HVAC systems serving guest rooms or dwelling units.
One- and two-family dwellings.

Section N1106 PIPING INSULATION

N1106.1 Mechanical system piping insulation

Mechanical system piping capable of carrying fluids above 105°F (40.5°C) or below 55°F (13°C) shall be insulated to a minimum of R-3.

N1106.2 Domestic and service hot water systems

Domestic hot water piping located outside the building thermal envelope shall be insulated to a minimum of R-3.

Section N1107 LIGHTING

N1107.1 General

The provisions of this section apply to lighting equipment, related controls and electric circuits serving all conditioned and unconditioned interior floor space and exterior building facades of all dwelling units and guest rooms within residential buildings and structures, or portions thereof.

N1107.2 High-efficacy lamps

All permanently installed lighting fixtures shall contain high-efficacy lamps. Screw-in compact fluorescent and LED lamps comply with this requirement.

The building official shall be notified in writing at the final inspection that the permanently installed lighting fixtures have met this requirement.

Exception: Two permanently installed lighting fixtures are not required to have high-efficacy lamps.

N1107.3 High-efficacy exterior lighting

All exterior lighting fixtures affixed to the exterior of the building shall contain high-efficacy lamps.

Exception: Two permanently installed lighting fixtures are not required to have high-efficacy lamps.

N1107.4 Solar ready

Reserved. This section will be updated with an interim amendment. See oregon.gov/bcd.

N1107.5 Electric vehicles

Reserved. This section will be updated with an interim amendment. See oregon.gov/bcd.

Section N1108 PLUMBING FIXTURE EFFICIENCY

N1108.1 General

This section shall apply to plumbing fixture efficiency.

N1108.1.1 Water closets

Water closets shall be EPA WaterSense labeled, with an effective flush volume not exceeding 1.28 gallons per flush.

N1108.1.2 Shower heads

Shower heads shall be EPA WaterSense labeled, with maximum flow rate not exceeding 2.0 gallons per minute.

Section NA1109 ALTERNATIVE SYSTEMS ANALYSIS

This section provides an alternative method of demonstrating code compliance with this chapter by demonstrating that such deviation will result in an annual energy consumption equal to or less than a building that is in compliance with this chapter.

NA1109.1 Equivalent annual energy consumption

The baseline design, conforming to requirements specified in this chapter and the proposed design shall be analyzed using the same procedures. The analyses shall use equal floor area and equal environmental requirements. The comparison shall be expressed in Btu input per gross building square foot of conditioned space per year (MJ/m² per year).

NA1109.2 Basis for comparison

Both baseline and proposed alternative designs shall include parameters as specified in Table NA1109.2.

TABLE NA1109.2
BASIS FOR COMPARISON
INPUT PARAMETERS FOR ANALYSIS
Parameter	Proposed Building	Code Baseline
Building Envelope
Opaque construction materials	As designed	Code minimum
Fenestration performance	As designed	Code minimum
Shading devices	As designed	Same as proposed
Window area	As designed	Same as proposed
Skylight area	As designed	Same as proposed^b
Building orientation	As designed	Same as proposed
Solar gain	As designed	Same as proposed
Building infiltration	0.35 ACH Natural	Same as proposed
HVAC Systems
HVAC system type(s)	As designed	Same as proposed
HVAC efficiency	Code efficiencies^c	Same as proposed^c
Heating fuel	As designed	Same as proposed
Cooling fuel	As designed	Same as proposed
Temperature setpoints	As designed	Same as proposed
Equipment capacity	As designed	Same as proposed
Mechanical ventilation	As designed	Same as proposed
Lighting
Artificial lighting	As designed	Code required
Daylighting	As designed	Same as proposed
Design Conditions
Building occupancy	As designed	Same as proposed
Building operational schedules	As designed	Same as proposed
Climatic data	As designed	Same as proposed
Internal loads	As designed	Same as proposed
Cooking fuel	As designed	Same as proposed

For a single-family dwelling unit, detached or attached (townhouse) only, code baseline window area may be 13 percent of heated space floor area when proposed building has less than 13 percent of heated space floor area in windows.
Code baseline skylight area shall be same as proposed up to a maximum of two percent of the heated space floor area.
Systems not regulated by code, such as electric heat, shall comply with standard equipment efficiency for such equipment.

NA1109.2.1 Internal heat gain

The total internal heat gain shall be calculated by Equation NA1109.2.1(1). For single zone calculations, the daily total sensible internal gains (Btu/day) shall be determined by Equation NA1109.2.1(2). For multiple zone HVAC systems, the daily total sensible internal gains (Btu/day) shall be determined by Equation NA1109.2.1(2) for the living zone and Equation NA1109.2.1(3) for the sleeping zone. The daily total latent load for each zone shall be determined using Equation NA1109.2.1(4).

Internal heat gains shall be distributed over the day according to the profile in Table NA1109.2.

Where multiple zone space conditioning is modeled, the profile shown for Zone 2 shall be used for bedrooms and bathrooms; the profile shown for Zone 1 shall be used for all other conditioned rooms. Where single zone space conditioning is modeled, the hourly profile for single-zone designs shall be used.

Equation NA1109.2.1(1)
Total Heat Gains = Sensible Heat Gains + Latent Heat Gains

Equation NA1109.2.1(2)
Single Zone or Living Zone:
Sensible Heat Gains = (Floor Area of Zone 15 Btu/day ft²) + (Number of living units 20,000 Btu/day)

Equation NA1109.2.1(3)
Sleeping Zone:
Sensible Heat Gains = Floor Area of Zone 15 Btu/day ft²

Equation NA1109.2.1(4)
Latent Heat Gains = 0.2 Sensible Heat Gains

NA1109.2.2 Thermostat set-points

In the analysis for both the baseline and proposed designs, all conditioned spaces shall be maintained at the specified thermostat setpoints at all times except for minor deviations at thermostat setback and setup and when outdoor conditions exceed normal design conditions.

If the specified equipment in the proposed design is too small to meet the load, its capacity shall be increased in the calculations. If equipment to meet a load is not included in the design, such equipment shall be assumed in the calculations and its energy use included. In no case shall the energy use of proposed design be reduced by not conditioning its spaces.

For central space conditioning systems without zonal control, the entire conditioned floor area shall be on thermostatically controlled zone. The thermostat settings shall be those listed for a single zone in Table NA1109.2.2. For multiple zone designs, the multizone thermostat settings in Table NA1109.2.2 shall be used. Zone 1 represents all conditioned spaces other than Zone 2 (bedrooms and bathrooms). The effect of heat transfer between zones, including nonclosable openings shall be included in the calculation

TABLE NA1109.2.2
THERMOSTAT SETTINGS (°F)
TIME OF DAY	SINGLE ZONE		MULTIPLE ZONE
	Heat	Cool	Zone 1 Living		Zone 2 Sleeping
	Heat	Cool	Heat	Cool	Heat	Cool
6 – 9 a.m.	68	78	68	78	68	78
9 a.m. – 5 p.m.	68	78	68	78	60	85
5 – 11 p.m.	68	78	68	78	68	78
11 p.m. – 6 a.m.	60	78	60	85	60	78

NA1109.3 Analysis procedure

The analysis of the annual energy usage of the standard and the proposed alternative building and system designs shall meet the following criteria:

NA1109.3.1

The building heating/cooling load calculation procedure used for annual energy consumption analysis shall be of sufficient detail to permit the evaluation of effect of building data (such as orientation, size, shape, transfer characteristics of mass, air, moisture, and heat) and hourly climatic data.

NA1109.3.2

The calculation procedure used to simulate the operation of the building and its service systems through a full year operating period shall be of sufficient detail to permit the evaluation of the effect of system design, climatic factors operational characteristics, and mechanical equipment on annual energy usage. Manufacturer’s data or comparable field test data shall be used when available in the simulation of all systems and equipment. The calculation procedure shall be based on 8760 hours of operation of the building and its service systems and shall utilize techniques recommended in the appropriate ASHRAE publications or produce results consistent with such recommended procedures.

NA1109.3.2.1

The calculation procedure shall explicitly cover the following items:

Climatic data: coincident hourly data for temperatures, solar radiation, wind and humidity of typical days in the year representing seasonal variation.
Building data: orientation, size, shape, mass, air, moisture and heat transfer characteristics.
Operational characteristics: temperature, humidity, ventilation, illumination, control mode for occupied and non-occupied hours.
Mechanical equipment: design capacity, part load profile.
Internal heat generation: lighting, equipment, number of people during occupied and non-occupied periods.

NA1109.4 Documentation

Proposed alternative designs, submitted as requests for exception to the standard design criteria, shall be accompanied by an energy analysis comparison report prepared by a registered engineer. The report shall provide sufficient technical detail describing the differences between the two building and systems designs and on the data used in and resulting from the comparative analysis.

NA1109.4.1

The documentation shall demonstrate that the analysis used is consistent with the techniques and procedures specified in this section and the following ASHRAE documents:

2001 ASHRAE Handbook of Fundamentals.
2000 ASHRAE Handbook of HVAC Systems and Equipment.
ASHRAE Principles of Heating, Ventilating and Air Conditioning.

Section NF1110 SCOPE

NF1110.1 General

All windows installed in Oregon shall meet the requirements of this section.

Section NF1111 ALTERATIONS

NF1111.1 Windows

Windows shall be tested and labeled in accordance with Section N1104.4.

The following information is repeated for the reader’s convenience:

N1104.4 Windows. All windows installed in Oregon shall meet the requirements of Part III, Fenestration Standard.

Decorative or unique architectural feature glazing not exceeding 1 percent of the heated space floor area is exempt from thermal performance requirements and does not need to be included in Table N1104.1(1) thermal performance calculations.
Glass block assemblies may use a U-factor of 0.51.

The U-factor for windows may be a weighted average of total window area when all other building envelope measures are in compliance with performance requirements specified in this code. This calculation shall be provided to the building official and the windows that are less than required for prescriptive compliance shall be identified on the plans.

Section NF1112 DEFINITIONS

NF1112.1 General

For purposes of this section the following definitions are provided;

WINDOWS PRODUCED IN LOW VOLUME are a manufacturer’s product installed in Oregon during a calendar year that does not exceed: 750 windows, 500 glazed doors, 1,000 skylights covered in Section NF1114.2 and 25 complete sunrooms/ solariums.

MANUFACTURER produces windows, assembles window components or does both. A “manufacturer” includes its subsidiaries, divisions and all other companies under common control or ownership.

SUNROOM/SOLARIUM. A one-story structure attached to a dwelling with a glazing area in excess of 40 percent of the gross area of that structure’s exterior walls and roof.

ALUMINUM WITH VINYL. Fenestration framing material consisting of a composite of both aluminum and vinyl framing constructed in a manner where the aluminum framing is provided a complete thermal break by the vinyl framing.

Section NF1113 INSULATED GLASS CERTIFICATION

NF1113.1 General

Sealed insulated glass units shall conform to, or be in test for, ASTM E774–97 Standard Practice for Evaluating Solar Absorptive Materials for Thermal Applications, as Class A under a Sealed Insulated Glass Manufacturers Association (SIGMA) approved certification program and installed in accordance with the SIGMA glazing specifications.

Section NF1114 WINDOW THERMAL PERFORMANCE DESIGNATION FOR NEW BUILDINGS AND ADDITIONS

The requirements of this section are not intended to waive or supersede any window thermal performance requirements under state or federal laws.

NF1114.1 Manufactured windows

U-factors for manufactured fenestration products (windows, skylights and doors) shall be determined in accordance with the National Fenestration Rating Council (NFRC) 100 2001 Procedure for Determining Fenestration Product U-Factors The U-factors shall be labeled and certified in accordance with the NFRC Product Certification.

NF1114.2 Windows products exempt from testing

The following products are exempt from thermal performance testing as specified in Section NF1114.1.

Windows produced in low volume.
Glazing not exceeding 1 percent of the heated space floor area.
Solariums and sunrooms.
Skylights constituting no more than 10 percent of total glazing in a residential building.
Skylights constructed with wood, thermal break aluminum or aluminum with vinyl frames with a glazing configuration of either: a minimum 0.5-inch (12.7 mm) space between the panes and low-e glass; or triple layered acrylic.

NF1114.2.1 Thermal performance of exempted products

The thermal performance of window products exempted from testing shall be determined by the following procedures:

Windows produced in low volume are assigned default U-factors as specified in Section NF1114.3, Item 1.
Glazed doors produced in low volume are assigned default U-factors as specified in Section NF1114.3, Item 2.
Skylights produced in low volume are assigned default U-factors as specified in Section NF1114.3, Item 3.
Skylights constituting no more than 10 percent of total glazing in a residential building that are exempt from testing are assigned default U-factors as specified in Section NF1114.3, Item 3.
Vertical and overhead glazing contained in sunrooms/ solariums are assigned default U-factors as specified in Section NF1114.3, Items 1, 2 and 4.
Skylights specified in Section NF1114.2, Item 5 shall be assigned a default U-factor of 0.50.

NF1114.3 Thermal performance validation for windows produced in low volume or site-built

Windows, glazed doors, skylights and sunroom/solariums produced in low volume and meeting the requirements of this subsection may validate default U-factors:

By using Table NF1114.3(1) for windows,
By using Table NF1114.3(2) for glazed doors,
By using Table NF1114.3(1) for skylights based on an overall U-factor of U-0.50.
By using Table NF1114.3(1) for overhead glazing installed in sunrooms/solariums based on an overall U-factor of U-0.35.

TABLE NF1114.3(1)
APPROVED WINDOW DEFAULT U-VALUES^{a, b}
DESCRIPTION^{c, d, e, f, g} (inches)	FRAME TYPE^h
DESCRIPTION^{c, d, e, f, g} (inches)	ALUMINUM THERMAL BREAKⁱ	WOOD/VINYL	ALUMINUM CLAD WOOD/ REINFORCED VINYL^j
Double, Clear ¼	N/A	0.56	0.59
Double, Clear ¼ + argon	0.63	0.53	0.56
Double, Low-e 4, ¼	0.61	0.52	0.54
Double, Low-e 2, ¼	0.58	0.49	0.51
Double, Low-e 1, ¼	0.55	0.47	0.49
Double, Low-e 4, ¼ + argon	0.55	0.47	0.49
Double, Low-e 2, ¼ + argon	0.52	0.43	0.46
Double, Low-e 1, ¼ + argon	0.50	0.41	0.43
Double, Clear ⅜	0.63	0.54	0.57
Double, Clear ⅜ + argon	0.60	0.51	0.54
Double, Low-e 4, ⅜	0.57	0.48	0.51
Double, Low-e 2, ⅜	0.54	0.45	0.48
Double, Low-e 1, ⅜	0.51	0.43	0.46
Double, Low-e 4, ⅜ + argon	0.53	0.44	0.47
Double, Low-e 2, ⅜ + argon	0.49	0.41	0.44
Double, Low-e 1, ⅜ + argon	0.47	0.39	0.41
Double, Clear ½	0.60	0.50	0.54
Double, Clear ½ + argon	0.58	0.48	0.51
Double, Low-e 4, ½	0.53	0.44	0.47
Double, Low-e 2, ½	0.50	0.41	0.44
Double, Low-e 1, ½	0.47	0.39	0.42
Double, Low-e 4, ½ + argon	0.50	0.42	0.44
Double, Low-e 2, ½ + argon	0.46	0.37	0.40
Double, Low-e 1, ½ + argon	0.43	0.35	0.38
Triple, Clear ¼	0.52	0.42	0.44
Triple, Clear ¼ + argon	0.49	0.39	0.42
Triple, Low-e 4, ¼	0.50	0.40	0.40
Triple, Low-e 2, ¼	0.48	0.39	0.41
Triple, Low-e 1, ¼	0.47	0.38	0.40
Triple, Low-e 4, ¼ + argon	0.46	0.37	0.39
Triple, Low-e 2, ¼ + argon	0.43	0.34	0.37
Triple, Low-e 1, ¼ + argon	0.42	0.34	0.36
Triple, Clear ½	0.46	0.37	0.40
Triple, Clear ½ + argon	0.45	0.36	0.38
Triple, Low-e 4, ½	0.43	0.35	0.37
Triple, Low-e 2, ½	0.41	0.32	0.35
Triple, Low-e 1, ½	0.39	0.31	0.33
Triple, Low-e 4, ½ + argon	0.41	0.32	0.35
Triple, Low-e 2, ½ + argon	0.38	030	0.32
Triple, Low-e 1, ½ + argon	0.37	0.29	0.31

For SI: 1 inch = 25.4 mm.

Subtract 0.02 from the listed default U-factor for insulated spacers. Insulated spacer material includes fiberglass, wood and butyl or other material with an equivalent K-value.
Sunrooms/solariums may subtract 0.03 from the default U-factor.
¼″ = a minimum dead air space of 0.25 inch (6.4 mm) between the panes of glass.
⅜″ = a minimum dead air space of 0.375 inch (9.5 mm) between the panes of glass.
½″ = a minimum dead air space of 0.5 inch (12.7 mm) between the panes of glass.
Products with air spaces different than those listed above shall use the value for the next smaller air space; i.e. ¾ inch = ½-inch U-factor, ⁷⁄₁₆ inch = ⅜-inch U-factor, ⁵⁄₁₆ inch = ¼-inch U-factor.
Low-e 4 (emissivity) shall be 0.4 or less.
Low-e 2 (emissivity) shall be 0.2 or less.
Low-e 1 (emissivity) shall be 0.1 or less.
U-factors listed for argon shall consist of sealed, gas-filled, insulated units for argon, CO₂, SF₆ and argon/SF₆ mixtures. The following conversion factor shall apply to Krypton gas-filled units: ¼ inch (6.4 mm) or greater airspace with Krypton gas fill = ½-inch (12.7 mm) airspace with Argon gas-fill.
Dividers placed between glazing: The U-factors listed shall be used where the divider has a minimum gap of ⅛ inch (3.2 mm) between the divider and lite of each inside glass surface. Add 0.03 to the listed U-factor for True Divided Lite windows.
“Glass block” assemblies may use a U-factor of 0.51.
Insulated fiberglass framed products shall use wood/vinyl U-factors.
“Glass block” assemblies may use a U-factor of 0.51.
Insulated fiberglass framed products shall use wood/vinyl U-factors.
Aluminum Thermal Break = An aluminum thermal break framed window shall incorporate the following minimum design characteristics:
1. The thermal conductivity of the thermal break material shall be not more than 3.6 Btu-in/h • ft² • °F;
2. The thermal break material shall not be less than 0.210 inch; and
3. All metal framing members of the product to interior and exterior air must incorporate a thermal break meeting the criteria in 1 and 2 above.
Aluminum clad wood windows shall use the U-factors listed for Aluminum Clad Wood/Reinforced Vinyl windows. Vinyl clad windows shall use the U-factors listed for Wood/Vinyl windows. Any vinyl frame window with metal reinforcement in more than one rail shall use the U-factors listed for Aluminum Clad Wood Reinforced Vinyl windows.

TABLE NF1114.3(2)
APPROVED GLAZED DOOR DEFAULT U-VALUES^a
DESCRIPTION^{b, c, d, e} (inches)	DOOR MATERIAL
	INSULATED^f	WOOD^g
	Full-Lite^{h, i}	Half-Lite^{j, k}	Full-Lite^h	Half-Lite^j
Double, Clear ¼	0.39	0.31	0.47	0.42
Double, Clear ¼ + argon	0.37	0.30	0.45	0.41
Double, Low-e 4, ¼	0.36	0.30	0.44	0.41
Double, Low-e 2, ¼	0.35	0.29	0.43	0.40
Double, Low-e 1, ¼	0.24	0.28	0.41	0.39
Double, Low-e 4, ¼ + argon	0.33	0.28	0.41	0.39
Double, Low-e 2, ¼ + argon	0.31	0.26	0.39	0.38
Double, Low-e 1, ¼ + argon	0.31	0.26	0.38	0.37
Double, Clear ⅜	0.37	0.30	0.45	0.41
Double, Clear ⅜ + argon	0.36	0.29	0.44	0.41
Double, Low-e 4, ⅜	0.34	0.28	0.42	0.40
Double, Low-e 2, ⅜	0.33	0.28	0.41	0.39
Double, Low-e 1, ⅜	0.21	0.26	0.38	0.37
Double, Low-e 4, ⅜ + argon	0.32	0.27	0.40	0.38
Double, Low-e 2, ⅜ + argon	0.29	0.25	0.37	0.37
Double, Low-e 1, ⅜ + argon	0.29	0.25	0.36	0.36
Double, Clear ½	0.36	0.29	0.44	0.41
Double, Clear ½ + argon	0.34	0.28	0.42	0.40
Double, Low-e 4, ½	0.32	0.27	0.40	0.38
Double, Low-e 2, ½	0.30	0.26	0.38	0.37
Double, Low-e 1, ½	0.19	0.25	0.36	0.36
Double, Low-e 4, ½ + argon	0.30	0.26	0.38	0.37
Double, Low-e 2, ½ + argon	0.28	0.25	0.36	0.36
Double, Low-e 1, ½ + argon	0.28	0.24	0.34	0.35
Triple, Clear ¼	0.31	0.26	0.39	0.38
Triple, Clear ¼ + argon	0.29	0.25	0.37	0.37
Triple, Low-e 4, ¼	0.30	0.26	0.38	0.37
Triple, Low-e 2, ¼	0.29	0.25	0.37	0.36
Triple, Low-e 4, ¼ + argon	0.27	0.24	0.35	0.35
Triple, Low-e 2, ¼ + argon	0.26	0.24	0.34	0.35

For SI:1 inch = 25.4 mm.

Subtract 0.02 from the listed default U-factor for insulated spacers. Insulated spacer material includes fiberglass, wood and butyl or other material with an equivalent K-value.
¼″ = a minimum dead air space of 0.25 inch (6.4 mm) between the panes of glass. ⅜″ = a minimum dead air space of 0.375 inch (9.5 mm) between the panes of glass. ½″ = a minimum dead air space of 0.5 inch (12.7 mm) between the panes of glass.
Products with air spaces different than those listed above shall use the value for the next smaller air space; i.e., ¾ inch = ½-inch U-factor, ⁷⁄₁₆ inch = ⅜-inch U-factor, ⁵⁄₁₆ inch = ¼-inch U-factor.
Low-e 4 (emissivity) shall be 0.4 or less.
Low-e 2 (emissivity) shall be 0.2 or less.
Low-e 1 (emissivity) shall be 0.1 or less.
U-factors listed for argon shall consist of sealed, gas-filled, insulated units for argon, CO₂, SF₆ and argon/SF₆ mixtures. The following conversion factor shall apply to Krypton gas-filled units: ¼-inch or greater airspace with Krypton gas fill = ½ -inch airspace with Argon gas-fill.
Dividers placed between glazing: The U-factors listed shall be used where the divider has a minimum gap of ⅛ inch between the divider and lite of each inside glass surface. Add 0.03 to the listed U-factor for true divided lite windows.
Insulated = Any urethane insulated foam core door with a thermal break. Thermal Break = A thermal break door shall incorporate the following minimum design characteristics:
1. The thermal conductivity of the thermal break material shall be not more than 3.6 Btu-in/h/ft²/°F; and
2. The thermal break material shall not be less than 0.210 inch.
Wood = Any wood door.
Full lite = A door that consists of more than 35-percent glazing.
Add 0.05 to the listed U-factor for full-lite values if insulated door does not have a thermal break.
Half lite = A door that consists of 35-percent or less glazing.
Add 0.06 to the listed U-factor for half-lite values if the insulated door does not have a thermal break.

Section NF1115 THERMAL PERFORMANCE LABELING

The requirements of this section are not intended to waive or supersede any window label or disclosure requirements under state or federal laws.

NF1115.1 Labels

Labels shall be either:

National Fenestration Rating Council (NFRC) certified product; or
State-approved labels.

Labeling is not required for glazing not exceeding one percent of the heated space floor area and is exempt from Table N1104.1(1) thermal performance calculations.

NF1115.2 Label description

All windows shall have stateapproved labeling except as provided in Section NF1115.1, Item 1.

Exceptions:

Labeling is not required for glazing not exceeding 1 percent of the heated space floor area.
Portions of labels for windows produced in low volume may be handwritten.

NF1115.2.1 Windows produced in low volume labels

NF1115.2.1 Windows produced in low volume labels. Labels for windows produced in low volume under NF1112(1), due to its frame and glazing configuration shall:

Specify window components;
Show the allowed U-factor in the appropriate location;
Show a production count number that does not exceed the maximums established in NF1112(1);
Imprint “(Manufacturer’s name) certifies the attached window is constructed in a manner to obtain the specified U-factor” or “(Manufacturer’s name) certifies the attached skylight complies with the criteria specified in the Oregon building codes”;
Be imprinted, not handwritten;
Face the interior of the room; and
Remain attached to the window until the building inspector inspects and verifies the labeling.

NF1115.3 Labels for skylights exempted from thermal performance standards

Labels for skylights exempt from thermal performance standards under Section NF1114.2, Item 5, because of its frame and glazing configuration shall:

Specify skylight components;
State “U-0.50 Default U-factor”;
State “Limited Production Skylight Compliance U-factor Label” and “Maximum Allowable Skylight Area Shall Not Exceed Two Percent of the Heated Space Floor Area”;
Show a production count number that does not exceed the maximums established in Section NF1112.1.
Imprint “(Manufacturer’s name) certifies the attached skylight complies with the criteria specified in the Oregon building codes;”
Contain the statement, “This skylight is not required to be tested or evaluated for thermal performance”;
State “EXEMPT” in 0.75-inch (20 mm) high letters;
Specify “Issued (Date of issue)”;
Contain the statement, “Under ORS 455.525(4) this skylight is deemed to comply with Oregon’s thermal performance standards regardless of U-factor.”

NF1115.4 Labels for sunrooms/solariums produced in low volume or exempted from testing

Labels for solariums and sunrooms produced in low volume or with 0.5-inch (12.7 mm) airspace between the glazing shall:

Specify the components for each of the glazed surfaces, such as the front, overhead, and each side;
Show a production count number that does not exceed the maximums established in Section NF1112;
Show the U-factor determined by Section NF1114.2.1, Item 5 or NF1114.3, Item 4 for each of the glazed surfaces;
Imprint “(Manufacturer’s name) certifies the components of this sunroom or solarium are constructed in a manner to obtain the specified U-factor”; and
Have one label providing a description of each of the glazed surfaces.

NF1115.5 Labels for skylights exempt from testing

Labels for skylights that are exempt from testing in accordance with Section NF1114.2(4) shall:

Specify skylight components;
State “Calculated U-factor Skylight Compliance Label”;
State U-factor determined by Section NF1114.2.1, Item 4; and
Show a production count number that does not exceed the maximums established in Section NF1112.

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