Report City of Tigard—2017 RESIDENTIAL CODE SUMMARY
1. The glazing areas need not be openable where the opening is not required by R310 and an approved
mechanical ventilation system is provided capable of 0.35 air changes per hour in the room or a whole-house
mechanical ventilation system is installed capable of supplying outdoor ventilation air of 15 cfm per
occupant computed on the basis of two occupants for the first bedroom and one occupant for each
additional bedroom.
2. The glazed areas need not be provided in rooms where EXCEPTION 1 above is satisfied and artificial light
is provided capable of producing an average illumination of 6 foot-candles over the area of the room at a
height of 30"above the floor level.
3. Use of sunroom additions and patio covers,as defined in R202, shall be permitted for natural ventilation if
in excess of 40%of the exterior sunroom walls are open,or are enclosed only by insect screening.
3. Rooms with bathing or spa facilities. Any room with a bathtub, shower or spa facility shall be provided with
mechanical ventilation which shall be designed and installed in accordance with M1507.4,R303.3.1.
Bathrooms without bathing or spa facilities. Water closet compartments or toilet rooms without bathtub, shower or
spa facilities shall be provided with aggregate glazing area of not less than three square feet, one-half of which must be
openable R303.3.2.
EXCEPTION:The glazed areas shall not be required where artificial light and a mechanical ventilation system
are provided.The minimum ventilation rate shall be in accordance with Table M1507.3.
4. Safety glazing is required in windows where the nearest vertical edge is within 24"of a door,at sliding glass doors,French
doors,tub enclosures and glazing adjacent to stairways,landings and ramps.For specific requirements,refer to R308.4.
5. Required heating.Every dwelling unit shall be provided with heating facilities capable of maintaining a minimum room
temperature of 68°F at a point 3' above the floor and 2' from exterior walls in all habitable rooms at the design
temperature. The installation of one or more portable space heaters shall not be used to achieve compliance with this
section R303.8.
MINIMUM ROOM AREAS,AND CEILING HEIGHT
6. Every dwelling unit shall have at least one habitable room that shall have not less than 120 square feet of floor area.
Other habitable rooms shall have a floor area of not less than 70 square feet. Habitable rooms,except kitchens, shall not
be less than 7'in any horizontal dimension R304.
7. Habitable rooms,hallways,corridors,bathrooms,toilet rooms,laundry rooms and basements, shall have a ceiling height
of not less than 7'.The required height shall be measured from the finished floor to the lowest projection from the ceiling
R305.
EXCEPTIONS:
1. Beams and girders spaced not less than 4'on center may project not more than 6"below the required ceiling
height.
2. Ceilings in basements without habitable spaces may project to within 6'-8"of the finished floor;and beams,
girders,ducts or other obstructions may project to within 6'-4"of the finished floor.
3. Not more than 50%of the required floor area of a room or space is permitted to have a sloped ceiling less
than 7'in height with no portion of the required floor area less than 5'in height.
4. Not more than 75%of the floor area of a bathroom or toilet room is permitted to have a sloped ceiling less
than 7' in height, provided an area of 21"x 24"is front of toilet and lavatories has a minimum of 6'-4"in
height,measured from the finished floor.An area of 24"x30"is front of and inside a tub shower shall have a
minimum of 6'-4"in height,measured from the standing surface of the fixture.
TOILET,BATH,AND SHOWER SPACES
8. Space required.Fixtures shall be spaced as shown in Figure R307.1.
9. Bathtub and shower spaces. Bathtub and shower floors and walls above bathtubs with installed showerheads and in
shower compartments shall be finished with a nonabsorbent surface.Such wall surfaces shall extend to a height of not less
than 6'above the floor R307.2.
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City of Tigard—2017 RESIDENTIAL CODE SUMMARY
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r."..: 7-4 MEANS OF EGRESS
10. Means of Egress.All dwelling units shall be provided with a means of egress as provided in this section. The means of
24 egress shall provide an unobstructed path of vertical and horizontal egress travel to the exterior without passing through a
garage or carport.R311.1
. 11. Egress Door. At least one egress door shall be provided for each dwelling unit. This door shall be side hinged and
X04) provide minimum clear width of 32 inches. The minimum clear height shall not be less than 78 inches. It shall be open
able from the inside without the use of a key or special knowledge. R311.2
12. Attachment. Required exterior exit balconies, stairs and similar exit facilities shall be positively anchored to the primary
}kms ' structure to resist both vertical and lateral forces. Such attachment shall not be accomplished by use of toenails or nails
'' > subject to withdrawal R311.5.1
,:` -CLOTHES DRYER EXHAUST
"13. ; Dryer exhaust systems shall be independent of all other systems, shall convey the moisture to the outdoors and shall
terminate on the outside of the building. Exhaust duct terminations shall be made with a full opening exhaust outlet or in
accordance with the dryer manufacturer's installation instructions. Screens shall not be installed at the duct termination.
Exhaust ducts shall not be connected with sheet-metal screws or fastening means which extend into the duct. Exhaust
ducts shall be equipped with a backdraft damper.The entire exhaust system,excluding transition ducts,shall be supported
and secured in place. Exhaust ducts shall be constructed of minimum 0.016" thick rigid metal ducts, having smooth
' - ;1'4,71interior surfaces with joints running in the direction of airflow. Flexible transition ducts used to connect the dryer to the
" exhaust duct system shall be limited to single length, not to exceed 8'in length. Transition ducts shall not be concealed
� r
i•Wri.",i'':*"*F-A"tt within construction,M1502.1,M1502.2,M1502.4 and M1502.5.
Exhaust duct size.The diameter of the exhaust duct shall be a minimum of 4"or as required by the clothes dryer's listing
and the manufacturer's installation instruction M1502.3.
Length limitation.The maximum length of a clothes dryer exhaust duct shall not exceed 35' from the dryer location to
t the wall of roof termination. The maximum length of the duct shall be reduced 2.5' for each 45%bend and 5' for each
•
90%bend per Table 1502.4.4.1.The maximum length of the exhaust duct does not include the transition duct M1502.7.
EMERGENCY ESCAPE AND RESCUE OPENINGS
*,� 14. Emergency Escape and Rescue.Basements and every sleeping room shall have at least one openable emergency escape
and rescue opening. Where basements contain one or more sleeping rooms, emergency egress and rescue openings shall
be required in each sleeping room,but shall not be required in adjoining areas of the basement.Where emergency escape
?' and rescue openings are provided they shall have a sill height of not more than 44"above the floor.Where a door opening
• having a threshold below the adjacent ground elevation serves as an emergency and rescue opening and is provided with.a
" `s' �-= bulkhead enclosure,the bulkhead enclosure shall comply with R310.3.The net clear opening dimensions required by this
section shall be obtained by the normal operation of the emergency escape and rescue opening from the inside. Escape
and rescue and rescue openings with a finished sill height below the adjacent ground elevation shall be provided with a
window well in accordance with R310.2.Emergency escape and rescue openings shall open directly into a public way, or
a =. �, to a yard or court that opens to a public way R310.1
-14
EXCEPTION: Basements used only to house mechanical equipment and not exceeding total floor area of 200
square feet.
n" Minimum opening area:All emergency escape and rescue openings shall have a minimum net clear opening of 5.7 sq. ft.
R310.1.1.
f EXCEPTION: Grade floor openings sill height not more than 44"above or below finished ground level shall
t ,01, have a minimum net clear opening of 5 sq. ft.
Minimum opening height:The minimum net clear opening height shall be 24"R310.1.2.
fi
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f Minimum opening width:The minimum net clear opening width shall be 20"R310.1.3.
Operational constraints: Emergency escape and rescue openings shall be operational from the inside of the room
without the use of keys,tools or special knowledge R310.1.4.
LANDINGS
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City of Tigard—2017 RESIDENTIAL CODE SUMMARY
15. Landings at doors. There shall be a floor or landing on each side of each exterior door. The floor or landing at the
exterior door shall not be more than 1.5"lower than the top of the threshold. 8311. The landing shall be permitted to
have a slope not to exceed 0.25"unit vertical in 12"units horizontal(2%) R311.3
EXCEPTIONS:
1. Where a stairway of three or fewer risers is located on the exterior side of a door, other than the required
exit door,a landing is not required for the exterior side of the door provided the door,other than an exterior
storm or screen door does not swing over the stairway.
2. The exterior landing at an exterior doorway shall not be more than 8" below the top of the threshold,
provided the door,other than an exterior storm or screen door does not swing over the landing.
3. The height of floors at exterior doors other than the exit door required by R311.4.1 shall not be more than
8"lower than the top of the threshold.
The width of each landing shall not be less than the door served.R311.3
At stairs:There shall be a floor or landing at the top and bottom of each stairway. R311.7.5
EXCEPTION:At the top of a flight of stairs,provided a door does not swing over the stairs R311.7.5
Size: The width of each landing shall not be less than the stairway or door served. Every landing shall have a minimum
dimension of 36"measured in the direction of travel,R311.3
STAIRWAYS
16. Width: Stairways shall be not less than 36"in clear width at all points above the permitted handrail height and below the
required headroom height. Handrails shall not project more than 4.5"on either side of the stairway and the minimum clear
width at and below the handrail height, including treads and landings, shall not be less than 31.5"where a handrail is
installed on one side and 27"where handrails are provided on both sides. R311.7.1
Treads and risers:The maximum riser height shall be 8"and the minimum tread depth shall be 9".The riser height shall
be measured vertically between the leading edges of the adjacent treads.The tread depth shall be a minimum of 6 inches
and shall be measured horizontally between the vertical planes of the foremost projection of adjacent treads and at a right
angle to the tread's leading edge.The walking surface of treads and landings of a stairway shall be sloped no steeper than
one unit vertical in 48 units horizontal (2%slope).The greatest riser height within any flight of stairs shall not exceed the
smallest by more than 3/8".The greatest tread depth within any flight of stairs shall not exceed the smallest by more than
3/8".R311.7.4,R311.7.4.2
Profile: The radius of curvature at the leading edge of the tread shall be no greater than 9/16". A nosing not less than
3/4"but not more than 1-1/4"shall be provided on stairways with solid risers. The greatest nosing projection shall not
exceed the smallest nosing projection by more than 3/8"between two stories, including the nosing at the level of the
floors and landings. Beveling of nosing shall not exceed 1/z". Risers shall be vertical or sloped from the underside of the
leading edge of the tread above at an angle not more than 30° from the vertical. Open risers are permitted,provided that
the opening between treads does not permit the passage of a 4"diameter sphere R311.7.4.3.
EXCEPTIONS:
1. A nosing is not required where the tread depth is a minimum of 10".
2. The opening between adjacent treads is not limited on stairs with a total rise of 30"or less.
Steps.The rise of a step shall not be less than 4"or greater than 8",R311.7.4.5.
Slope. Where the top or bottom riser adjoins a slopping walk,garage floor or driveway, the top or bottom riser may be
reduced to less than 4"in height with the variation height of the riser not to exceed 3"in every 3'of walk or stairway width
R311.7.4.6.
Headroom. The minimum headroom in all parts of the stairway shall not be less than 6'-8" measured vertically from the
sloped plane adjoining the tread nosing,or from the floor surface of the landing platform R311.7.2.
Winders. Winder treads shall have a minimum tread depth of 9" measured as above at a point 12" from the side where
the treads are narrower.Winders tread shall have a minimum tread depth of 6"at any point.Within any flight of stairs,the
greatest winder tread depth at the 12"walk line shall not exceed the smallest by more than 3/8",R311.7.4.2.
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City of Tigard-2017 RESIDENTIAL CODE SUMMARY
Spiral stairways:R311.7.9.1
Stairway illumination:All interior and exterior stairways shall be provided with a means to illuminate the stair,including
landing and treads. Interior stairways shall be provided with an artificial light source located in the immediate vicinity of
each landing of the stairway R303.6.
RAMPS
17. Ramps shall have a maximum slope of one unit vertical in twelve units horizontal(8.3%slope).
EXCEPTION: Where it is technically infeasible to comply because of site constraints, ramps may have a
maximum slope of one unit vertical to eight units horizontal(12.5%slope) R311.8.1.
Accessibility: Dwelling units required to be accessible by ORS 447.231 shall comply with Chapter 11 of the ORSC as
Al applicable.
.�R
HANDRAILS AND GUARDRAILS
18. st Handrails shall be provided on at least one side of each continuous run of treads or flight with four or more risers.The
#: , continuous handrail required for winders shall be located on the side where the tread is narrower R311.7.7.
i;42;#014.4-itilt: Handrails height, measure vertically from the sloped plane adjoining the tread nosing, or finish surface of ramp slope,
-' shall be not less than 30"and not more than 38"R311.7.7.1.
Continuity: Handrails for stairways shall be continuous for the full length of the flight, from a point directly above the
top riser of the flight to a point directly above lowest riser of the flight. Handrail ends shall be returned or shall terminate
in newel posts or safety terminals. Handrails adjacent to a wall shall have a space of not less than 1 1/2"between the wall
p I ' and the handrail R311.7.7.2.
EXCEPTIONS:
1. Handrails shall be permitted to be interrupted by a newel post at a turn.
N 2. The use of a volute,turnout,starting easing or starting newel shall be allowed over the lowest tread.
r•V't 4 Handrail grip size. All required handrails shall be of one of the following types or provide equivalent graspability
ig) _ ;itOto R311.7.7.3.
1. Type I.Handrails with a circular cross section shall have an outside diameter of at least 11/4"and not greater than 2".If
`" the handrail is not circular it shall have a perimeter dimension of at least 4"and not greater than 61/4"with a maximum
cross section of dimension of 2'/4".
2. Type II.Handrails with a perimeter greater than 61/4"shall provide a graspable finger recess area on both sides of the
profile.The finger recess shall begin within a distance of 3/4"measured vertically from the tallest portion of the profile
and achieve a depth of at least 5/16"with 7/8"below the widest portion of the profile. The minimum width of the
handrail above the recess shall be 11/4"to a maximum of 23/4".Edges shall have a minimum radius of 0.01".
19. Guards required. Porches,balconies or raised floor surfaces located more than 30"above the floor or grade below shall
have guards not less than 36"in height. R312.1, R312.2. Open sides of stairs with a total rise of more than 30" above the
floor or grade below shall have guards not less than 34" in height measured vertically from the nosing of the treads
R312.1.
Guard opening limitations. Required guards on open side of stairways, raised floor area, balconies and porches shall
have intermediate rails or ornamental closures which do not allow passage of a sphere 4"or more in diameter R312.3.
EXCEPTIONS:
1. The triangular openings formed by the riser,tread and bottom rail of a guard at the open side of a stairway
are permitted to be of such size that a sphere 6"cannot pass through.
2. Openings for required guardrails on the sides of stair shall not allow passage of a sphere 5" or more in
diameter to pass through.Opening limitations are applicable above the second riser of the stair.
SMOKE ALARMS
rti4
20. Smoke alarms shall be installed in the following locations:
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City of Tigard—2017 RESIDENTIAL CODE SUMMARY
1. In each sleeping rooms.
2. Outside of each separate sleeping area in the immediate vicinity of the bedrooms.
44.
3. On each additional story of the dwelling, including basements and cellars but not including crawl spaces and T.
uninhabitable attics. In dwellings or dwelling units with split levels and without an intervening door between the
adjacent levels, a smoke alarm installed on the upper level shall suffice for the adjacent lower level provided that the
lower level is less than one full story below the upper level.
Activation. When more than one smoke alarm is required to be installed within an individual dwelling unit the alarm
device shall be interconnected in such a manner that the actuation of one alarm will activate all of the alarms in the .'
individual unit.All smoke alarms shall be listed and installed with the provisions of this code.R314.5.
Prohibited locations: Required smoke alarms shall not be located within kitchens or garages or in other spaces where r >'
temperatures can fall below 40°F.Ionization smoke alarms shall not be located closer than 3'horizontally from: 74ae
1. The door to a kitchen.
2. The door to a bathroom containing a tub or shower;
3. The supply registers of a forced air heating or cooling system,outside the airflow from those registers. a
A smoke alarm installed within 20' of a cooking appliance shall be a photoelectric or the alarm shall have an approved
alarm silencing means. R314.3
Alterations, repairs and additions: When alterations, repairs or additions requiring a structural permit occur, or when
one or more sleeping rooms are added or created in existing dwellings,the individual dwelling unit shall be equipped with
smoke alarms located as required for new dwellings;the smoke alarms shall be interconnected and hard wired R314.3.1.
34,
EXCEPTIONS: 400�
1. Interconnection and hard-wiring of smoke alarms in existing areas shall not be required where alterations or *t'
kE�' �
repairs do not result in the removal of interior wall or ceiling finishes exposing the structure. X44 i
f
r,
2. Work involving the exterior surfaces of dwellings, such as the replacement of roofing or siding, or the f :
addition or replacement of windows or doors, or the addition of a porch or deck, are exempt from the
requirements of this section. 717*-41
New buildings power source: In new construction, the required smoke alarms shall receive their primary power from
the building wiring when such wiring is served from a commercial source, and when primary power is interrupted, shall i
receive power from a battery.Wiring shall be permanent and without a disconnecting switch other than those required for
overcurrent protection R314.4.
Existing buildings power source: Smoke alarms shall be permitted to be battery operated when installed in buildings lite t
without commercial power or in buildings that undergo alternations,repairs or additions regulated by R314.4.
GARAGES AND CARPORTS
21. Openings from a private garage directly into a room used for sleeping purposes shall not be permitted R302.5.1. „ $G
22. Garage separation.The garage shall be separated from the residence and its attic area by not less than 1/2"gypsum board 1 �
applied to the garage side. Garages beneath habitable rooms shall be separated from all habitable rooms above bynot less
PP g p Mel
than 5/8"Type X gypsum board or equivalent. Where the separation is a floor-ceiling assembly, the structure supporting rb
the separation shall also be protected by not less than'/2"gypsum board or equivalent. Garages located less than 3' from a ' _'
dwelling unit on the same lot shall be protected with not less than 1/2"gypsum board applied to the interior side of exterior
walls that are within this area. Openings between the garage and residence shall be equipped with solid wood doors not
less than 1-3/8"in thickness, solid or honeycomb core steel doors not less than 1-3/8 " thick, or 20-minute fire-rated ' o'
ti
doors R302.5,R302.6. M'
23. Garage and carport floors shall be of approved noncombustible materials. The area of floor used for parking of
automobiles or other vehicles shall be sloped to facilitate the movement of liquids to a drain or toward the main vehicle
entry doorway,R309.1.
EXCEPTION:Asphalt surfaces shall be permitted at ground level in carports R309.2. gin'"
ffiA
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City of Tigard—2017 RESIDENTIAL CODE SUMMARY
24. Protection from impact.Appliances located in a garage or carport shall be protected from impact by automobiles.Figure
M1307.1 contains examples of acceptable types of protection M1307.3.1.
• 25. Elevation of ignition source. Appliances having an ignition source shall be elevated such that the source of ignition is
TliV4e11; not less than 18"above the floor in garages M1307.3.
• FOOTINGS AND FOUNDATIONS
1. 4; 26. Minimum Compressive Strength at 28 Days:
Basement walls,foundation walls and other concrete not exposed to the weather 2500 psi
}` i ' • Basement slabs and interior slabs on grade,except garage floor slabs 2500 psi
Basement,foundation,exterior walls,other vertical concrete exposed to the weather .3000 psi
Porchescarport slabs and steps exposed to the weather and garage floor slabs, 3000 psi
Concrete shall be air entrained 5%-7% for strengths of 3000 and 3500 psi, and when subject to freezing and thawing
during construction for 2500 psi concrete,Table R402.2.
27. F• ootings shall be placed on undisturbed natural soil or engineered fill R403.1.
' <
28. 'Minimum depth. Bottoms of exterior wall, bearing wall, pier and column footings shall be not less than 12" below
`'finished grade R403.1.5.
1 ,
29. � M• inimum sizes for concrete or masonry footings shall be as set forth in Table R403.1,Figure R403.1 (1),and R403.1.1.
_. 30. Slope.The top surfaces of footings shall be level.The bottom surface of footings shall not have a slope exceeding one in
ten.Footings shall be stepped where the ground surface slopes more than one in ten,R403.1.6.
31 =. Ground clearance. Wood siding, sheathing and wall framing on the exterior of a building shall have a clearance of not
less than 6"from the ground or less than 2 inches vertically from exposed concrete.R317.1(6).
32. 4' Seismic reinforcing. Foundation with stem walls shall be provided with a minimum of one#4 bar within 12" of the top
1,6
of the wall and one#4 bar located 3"to 4"from the bottom of the footing R403.1.4.1.
EXCEPTION: Foundations constructed monolithically shall be permitted to have a minimum of two #4 bars
placed in the footing.
Where a construction joint is created between a concrete footing and stem wall, a minimum of one #4 bar shall be
provided at no more than 4'on center.The vertical bar shall extend 3"clear of the bottom of the footing,have a standard
hook and extend a minimum of 14"into the stem wall R403.1.4.
NOTE:Unless otherwise detailed on plan,a 6"90 degree bend on the short leg(hook)will be considered as meeting the
intent of this section.
33. Grounding electrodes. When concrete reinforcing bars are installed in concrete footings, the following requirements
shall be met to provide for a grounding electrode system:
1. Uncoated#4 reinforcing bar installed not less than 3"from the bottom of the footing,and not less than 20'in length
encased with a minimum of 2"of concrete.
2. An uncoated #4 reinforcingbar stubbed upat least 12# above the floorplate line and tightly attached to the
reinforcing bar located in the fooling with three ties. The spliced lap of the stubbed up bar to the footing bar shall be
a minimum of 12"R403.1.7.
34. Wood sill plate anchor bolts shall be min. 1/2" diameter, 7" embedment,maximum 6'on center and not more than 12"
from a corner or mudsill splices or less than seven bolt diameters from mudsill splice. Provide a minimum two anchor
bolts per plate R403.1.8 and R403.1.8.1.
Plate washers conforming to R602.11.1 shall be provided for all anchor bolts over the full length of required braced wall
lines. Properly sized cut washers shall be permitted for anchor bolts in wall lines not containing braced wall panels. Plate
washers,a minimum of 0.229 inches by 3"x 3"in size,shall be installed between the foundation sill plate and the nut.The
hole in the plate washer is permitted to be diagonally slotted with a width of up to 3/16 inch larger than the bolt diameter
., and a slot length not to exceed 1-3/4", provided a standard cut washer is placed between the plate washer and the nut
R602.11.1.
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City of Tigard—2017 RESIDENTIAL CODE SUMMARY
35. Concrete slab on ground floors shall be not less than 31/2"thick.Where slabs and footings are constructed monolithically,
footings shall comply with requirements in Figure 403.1(1).
36. Concrete foundation walls. Concrete foundation walls shall be constructed as set forth in Tables R404.1.1(1) thru
R404.1.1(4) and shall also comply with the provisions of R404 and the applicable provisions of R402.2. In Seismic Design
Categories D1 and D2,concrete foundation walls shall comply with R404.1.4.
CRAWLSPACES
37. Access opening. Crawl spaces shall be provided with a minimum 18"x 24" inches access opening. Openings through a
perimeter wall shall be not less than 16"x 24".R408.3.
38. When any portion of the through-wall access is below grade, an areaway not less than 16"x 24" shall be provided. Pipes,
ducts and other construction must not obstruct accessibility to and within the crawlspace R408.3. See M1305.1.4 for
access requirements where mechanical equipment is located under-floor.
39. Under-floor space ventilation. The under-floor space between the bottom of the floor joists and the earth under any
building(except space occupied by a basement) shall have ventilation openings through foundation walls or exterior walls.
The minimum net area of ventilation openings shall not be less than 1 square foot for each 150 sq. ft. of under floor area
but may be increased to 1 sq. ft.per 1500 sq. ft. of under-floor area where the ground surface is covered by a 6-mil black
polyethylene sheeting with joints lapped 12 inches and extends up the walls 12 inches. One ventilating opening shall be
required within 3' of each corner of the building. The openings shall be covered with corrosion resistant wire mesh or
equivalent with 1/8" minimum dimension. Ventilation openings may be omitted on one side of a building. Ventilation
openings may be omitted when continuously operated mechanical ventilation is provided at a rate of one cfm for each 50
sq.ft.of under-floor area and ground surface is covered with an approved vapor barrier material R408.1 and R408.1(2).
40. Drainage.Provide water drainage from the crawl space by means of crawl space and foundation drains sloped for gravity
drainage and extending to a storm sewer, street gutter, road ditch or other drainage way or raise the finish grade in the
crawl space to the level of finish grade outside R408.5.
41. Removal of debris. The under-floor grade shall be cleaned of all vegetation and organic material. All wood forms used
for placing concrete shall be removed before a building is occupied or used for any purpose. All construction materials
shall be removed before a building is occupied or used for any purpose R408.4.
SURFACE AND GROUNDWATER CONTROL
42. Drainage. Surface drainage shall be diverted to a storm sewer conveyance or other approved point of collection so as not
to create a hazard.Lots shall be graded so as to drain surface water away from the foundation walls.The grade shall fall at
least 6"in the first 10'R401.3.
EXCEPTION: Where lot lines,walls, slopes or other physical barriers prohibit 6" of fall within 10', the final
grade shall slope away from the foundation at a minimum slope of 5%,and the water shall be directed to drains
or swales,or other means shall be provided to ensure drainage away from the structure. Swales shall be sloped a
minimum of 2% when located within 10' of the building foundation. Impervious surfaces within 10' of the
building foundation shall be sloped a minimum of 2%away from the building.
WATERPROOFING
43. Waterproofing. Exterior foundation walls that retain earth and enclose interior spaces and floors below grade shall be
waterproofed from the top of the footing to the finished grade R406.2.
PROTECTION AGAINST DECAY
44. Ground contact. All wood in contact with the ground, embedded in concrete in direct contact with the ground or
embedded in concrete exposed to the weather that supports permanent structures intended for human occupancy shall be
approved pressure-preservative-treated wood suitable for ground contact use,except untreated wood may be used where
entirely below groundwater level or continuously submerged in fresh water R317.1.2.
Location required. Protection from decay shall be provided in the following locations by the use of naturally durable
wood or wood that is preservative treated in accordance with AWPA U1 for species, product,preservative and end use.
Preservatives shall be listed in Section 4 of AWPA U1,R319.1.
1. Wood joists or bottom of wood structural floor when closer than 18" or wood girders when closer than 12" to-
exposed
oexposed ground in crawl spaces or unexcavated area located within the periphery of the building foundation.
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City of Tigard—2017 RESIDENTIAL CODE SUMMARY
2. All wood framing members and sill plates in contact with concrete or masonry foundation walls.
3. Sills and sleepers on a concrete or masonry slab that is in direct contact with the ground,unless separated from such
slab by an impervious moisture barrier.
4. The ends of wood girders entering exterior masonry or concrete walls having clearances of less than 1/2"on tops,side
and ends.
5. Wood siding, sheathing and wall framing on the exterior of a building having a clearance of less than 6" from the
ground.
6. Wood structural members supporting moisture permeable floors or roofs that are exposed to the weather, such as
concrete or masonry slabs,unless separated from such floors or roofs by an impervious moisture barrier.
7. Wood furring strips or other wood framing members attached directly to the interior of exterior masonry walls or
concrete walls below grade except where an approved vapor retarder is applied between the wall and the furring strips
or framing members.R317.1
Field Treatment. Field-cut ends, notches and drilled holes or preservative-treated wood shall be treated in the field in
accordance with AWPA M4,R317.1.1.
Wood columns. Wood columns shall be approved wood of natural decay resistance or approved pressure-preservative-
treated wood R317.1.4.
EXCEPTIONS:
1. Columns exposed to the weather or in basements when supported by concrete piers or metal pedestals
projecting 1" above a concrete floor or 6" above exposed earth and the earth is covered by an approved
impervious moisture barrier.
2. Columns in enclosed crawl spaces or unexcavated areas located within the periphery of the building when
supported by a concrete pier or metal pedestal at a height more than 8" from exposed earth and the earth is
covered by an impervious moisture barrier.
45. Fasteners. Fasteners and washers for pressure-preservative and fire-retardant-treated wood shall be of hot-dipped zinc-
coated galvanized steel, stainless steel,silicon,bronze,or cooper.The coating weights for zinc-coated fasteners shall be in
accordance with ASTM A 153.R317.3.
EXCEPTIONS:
1. 1/2"diameter or larger steel bolts.
2. Fasteners other than nails and timber rivets shall be permitted to be of mechanically deposited zinc-coated
steel with coating weights in accordance with ASTM B 695 Class 55 minimum.
FRAMING
46. Grading, Fasteners, and Moisture Content. Load bearing dimension lumber (including logs used in log home
construction) shall be identified by a grade mark.Refer to Tables R602.3 (1) &R602.3 (2) for fastener requirements R502
and R602.
Moisture Content.At the time of the installation of interior finishes,all moisture-sensitive wood framing members used
in construction shall have a moisture content of not more that 19%of the weight of dry wood framing members. Prior to
the issuance of a certificate of occupancy, the general contractor or the owner who was issued the structural permit shall
notify the building official on a division approved form that the contractor or the owner who was issued the structural
permit is aware of and has taken steps to meet this code requirement R318.2.
47. Design and construction. Floor framing shall be designed and constructed in accordance with Chapter 5, Figure
R502.2,and nailed in accordance with Tables R602.3 (1)and R602.3 (2).
48. Bearing.Joists and beams or girders must have not less than 1 1/2"inches of bearing on wood or metal or 3"on concrete
or masonry except where supported on a 1"x 4" ribbon strip and nailed to the adjacent stud or by the use of approved
joist hangers R502.6.
49. Floor systems.Joist framing from opposite sides over a bearing support shall lap a minimum of 3" and shall be nailed
together with a minimum of three 10d face nails. A wood or metal splice with strength equal to or greater than that
provided by the nailed lap is permitted R502.6.1.
50. Joists under bearing partitions shall be of adequate size to support the load. Double joists, sized to adequately support
the load, that are separated to permit the installation of piping or vents shall be full depth solid blocked with lumber not
less than 2"in nominal thickness spaced not more than 4'on center.Bearing partitions perpendicular to joists shall not be
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offset from supporting girders,walls or partitions more than the joist depth unless such joists are of sufficient size to carry
the additional load R502.4.
51. Joist framing.Joists framing into the side of a wood girder shall be supported by approved framing anchors or on ledger
strips not less than nominal 2"x 2"R502.6.2.
52. Lateral restraint at supports.Joists shall be supported laterally at the ends by full-depth solid blocking not less than 2"
nominal thickness; or by attachment to a full-depth header, band or rim joist, or to an adjoining stud or otherwise
provided with lateral support to prevent rotation R502.7.
53. Plywood gussets.Where posts and beam or girder construction is used,plywood gussets shall be provided at all post-to-
beam connections.Lateral bracing is required at the bottom end of posts exceeding 4'in length R502.9.
54. Wood floor and roof trusses shall be of approved design and shall be installed and braced in accordance with the design.
Trusses shall not be notched drilled cut or altered unless so provided in the design,R502.11.3 and R802.10. -
55. Cripple walls.Foundation cripple walls shall be framed of studs not less in size than the studding above.When exceeding
4' in height, such walls shall be framed of studs having the size required for an additional story. Cripple walls supporting
three stories shall be framed with 2"x 6" studs spaced not more than 16"on center R602.9.
Cripple walls with a stud height less than 14" supporting exterior walls or an interior braced wall line which is
supported by a continuous foundation as required by R602.10.9 shall be sheathed on at least one side with wood structural
panel that is fastened to both the top and bottom plates in accordance with Table 602.3(1),or these cripple walls shall be
constructed of solid blocking R602.9.
56. Wall bracing. Walls shall be braced in accordance with R602.10. For building in Seismic Design Categories D1 and D2,
walls shall be constructed in accordance with the additional requirements of R602.10.9,R602.10.11 and R602.11.
57. Stud grade.Studs shall be a minimum No.3,Standard or Stud grade lumber.
EXCEPTION:Bearing studs not supporting floors and nonbearing studs may be Utility grade lumber,provided
the studs are spaced in accordance with Table R602.3 (5),R602.2.
58. Fireblocking shall be provided to cut off all concealed draft openings (both vertical and horizontal) and to form an
effective fire barrier between stories,and between a top story and the roof space. R302.11 Wood fireblocking shall be 2"
nominal thickness,or two thicknesses of 1"nominal lumber with broken lap joints,or 23/32"wood structural panels with
joints backed by 23/23 wood structural panels or 3/4" particleboard with joints backed with same material, 1/2" gypsum
board,1/4"cement-based millboard or other noncombustible material securely fastened in place. Where unfaced fiberglass
is used as fireblocking,it must fill the entire cross section of the wall cavity to a minimum height of 16"R302.11.1.
Fireblocking shall be provided in wood-frame construction in the following locations:
1. In concealed spaces of stud walls and partitions, including furred spaces, at the ceiling and floor level and at 10'
intervals both vertical and horizontal. Batts or blankets of mineral wool or glass fiber or other approved non-rigid
materials shall be allowed as fireblocking in walls constructed using parallel rows of studs or staggered studs.
2. At all interconnections between concealed vertical and horizontal spaces such as occur at soffits, drop ceilings,cove
ceilings.
3. In concealed spaced between stair stringers at the top and bottom of the run. Enclosed spaced under stairs shall
comply with R302.7.
4. At openings around vents,pipes,ducts,cables and wires at ceiling and floor level,with an approved material to resist
the free passage of flame and products of combustion.
5. For the fireblocking of chimneys and fireplaces,see R1003.19.
6. Fireblocking of cornices of a two-family dwelling is required at the line of dwelling unit separation,
59. Draftstopping required. When there is usable space both above and below the concealed space of a floor/ceiling
assembly, draftstops shall be installed so that the area of the concealed space does not exceed 1,000 square feet.
Draftstopping shall divide the concealed space into approximately equal areas. Where the assembly is enclosed by a floor
membrane above and a ceiling membrane below draftstopping shall be provided in floor/ceiling assemblies under the
following circumstances:
1. Ceiling is suspended under the floor framing.
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2. Floor framing is constructed of truss-type open-web or perforated members R302.12.
60. Draftstopping materials shall be 1/2" gypsum board, 3/8" wood structural panels, and 3/8" Type 2-M-W particleboard
or other approved material adequately supported. Draftstops shall be installed parallel to the floor framing members
R302.12.1.
WALL AND CEILING COVERING
61. Gypsum wallboard shall be installed in accordance with Table R702.3.5,R702.3.
62. Flame spread. Wall and ceiling finishes shall have a flame spread classification of not greater than 200, and a smoke-
developed index of not greater than 450,R315.1 and R315.2.
63. Installation.Exterior sheathing shall be dry before applying exterior cover R701.2.
64. Water-resistive barrier. One layer of#15 asphalt felt, free from holes and breaks, complying with ASTM D 226 for
Type 1 felt or other approved water-resistive barrier shall be applied over studs or sheathing of all exterior walls. Such felt
or material shall be applied horizontally,with the upper layer lapped over the lower layer not less than 2". Where joints
occur,felt shall be lapped not less than 6".The felt or other approved materials shall be continuous to the top of walls and
terminated at penetrations and building appendages in a manner to meet the requirements of the exterior wall envelope as
described in R703.1.
65. Siding.Weather resistant siding shall be installed per Table R703.4.
66. Flashing. Approved corrosion-resistive flashing shall be applied shingle-fashion in such a manner to prevent entry of
water into the wall cavity or penetration of water to the building structural framing components. The flashing shall extend
to the surface of the exterior wall finish R703.8.
Approved corrosion-resistant flashings shall be installed at all of the following locations:
1. Exterior window and door openings. Flashing at exterior window and door openings shall extend to the surface of
the exterior wall finish or to the water-resistive barrier for subsequent drainage.
2. At the intersection of chimneys or other masonry construction with frame or stucco walls, with projecting lips on
both sides under stucco copings.
3. Under and at the ends of masonry,wood or metal copings and sills.
4. Continuously above all projecting wood trim.
5. Where exterior porches,decks or stairs attach to a wall or floor assembly of wood-frame construction.
6. At wall and roof intersections.
7. At built-in gutters.
ROOF CEILING CONSTRUCTION
67. Grade mark.Load bearing dimension lumber shall be identified by a grade mark R802.1.
68. Drainage control. All dwellings shall have a controlled method of water disposal from roofs that will collect and
discharge all roof drainage in accordance with the Plumbing Code,R801.3 and R801.4.
69. Framing details.Rafters shall be framed to ridge board or to each other with a gusset plate as a tie. Ridge boards shall be
at least 1" nominal thickness and not less in depth than the cut end of the rafter. At all valley and hips there shall be a
valley or hip rafter not less than 2"nominal thickness and not less in depth than the cut end of the rafter. Hip and valley
rafters shall be supported at the ridge by a brace to a bearing partition or be designed to carry and distribute the specific
load at that point. Where the roof pitch is less than three units vertical in 12 units horizontal, structural members that
support rafters and ceiling joists,such as ridge beams,hips and valleys,shall be designed as beams R802.3.
70. Ceiling joist and rafter connections. Ceiling joists and rafters shall be nailed to each other in accordance with Table
R802.5.1(9), and rafters shall be nailed to the top plate in accordance with Table R602.3(1). Ceiling joists shall be
continuous or securely joined in accordance with Table R802.5 (9)where they meet over interior partitions and are nailed
to adjacent rafters to provide a continuous tie across the building when such joists are parallel to the rafters. Where ceiling
joists are not connected to the rafters at the top plate,joists connected higher in the attic shall be installed as rafter ties,or
rafter ties shall be installed to provide a continuous tie. Where ceiling joists are not parallel to rafters,rafter ties shall be
installed. Rafter ties shall be a minimum of 2"x 4" nominal,installed in accordance with the connection requirements in
Table R802.5.1 (9), or connections of equivalent capacities shall be provided. Where ceiling joists or rafter ties are not
provided, the ridge formed by these rafters shall be supported by a wall or girder designed in accordance with accepted
engineering practice.Collar ties shall be spaced not more than 4'on center R802.3.1.
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71. Ceiling joists lapped. Ends of ceiling joists shall be lapped a minimum of 3"or butted over bearing partitions or beams
and toenail to the bearing members. Where ceiling joists are used to resist rafter thrust, lapped joists shall be nailed
together in accordance with Table R602.3 (1) and butted joists shall be tied together in a manner to resist such thrust
R802.3.2.
72. Bearing. The ends of each rafter or ceiling joist shall have not less than 1 1/2" of bearing on wood or metal and not less
than 3" on masonry R802.6.
73. Lateral support. Rafters and ceiling joists having a depth-to-thickness ratio exceeding five to one based on nominal
dimensions shall be provided with lateral support at points of bearing to prevent rotation R802.8.
74. Lumber sheathing. Allowable spans for lumber used as roof sheathing shall conform to Table R803.1. Spaced lumber
sheathing for wood shingles and shake roofing shall conform to the requirements of R905.7 and R905.8. Spaced lumber
sheathing is not allowed in Seismic Design Category D2 R803.1.
75. Attic access. Attics with a clear height of 30" or more must be provided with an access. The rough-framed access
opening shall be not less than 22"x 30"and shall be located in a hallway or other readily accessible location R807.1.
76. Ventilation required. Enclosed attics and enclosed rafter spaces formed where ceiling is applied to the underside of roof
rafters shall have cross ventilation for each separate space by ventilated openings protected against the entrance of rain or
snow. Ventilation openings shall be provided with corrosion-resistant wire mesh,with 1/8" minimum to 1/4" maximum
openings R806.1.For unvented attic assemblies,see R806.4.
77. Minimum area. The total net free ventilating area shall be not less than 1/150 of the space ventilated. The area may be
reduced to 1/300 if at least 50%but not more than 80%of the openings are in the upper part of the ventilated space and
at least 3' above the eave or cornice vents or when a vapor barrier not exceeding 1 perm transmission rate is installed on
the warm-in-winter side of the ceiling R806.2.
ROOF COVERING
78. Fasteners for roof covering shall be in accordance with Chapter 9 of the Oregon Residential Specialty Code, based on
type of material used. In all cases, fasteners shall be long enough to penetrate into roof sheathing 3/4" or through the
thickness of sheathing,whichever is less R905.2.6 and R905.3.6
79. Roof covering application. Roof coverings shall be applied in accordance with the applicable provisions of this section
and the manufacture's installation instructions R905.1.
CHIMNEYS AND FIREPLACES
80. Seismic reinforcing. Masonry or concrete chimneys in Seismic Design Category D1 or D2 shall be reinforced.
Reinforcing shall conform to the requirements set forth in Table R1001.1,R609,R1001.3,R1001.3.1,R1001.3.2,R1001.4
and RI001.4.1.
81. Foundation. Masonry fireplaces and their chimneys shall be supported on foundations of solid masonry or concrete at
least 12" thick and shall extend at least 6" beyond the face of the fireplace or foundation wall on all sides. Footings shall
be placed on natural,undisturbed earth or engineered fill below frost depth. In areas not subjected to freezing, footings
shall be at least 12 inches below finished grade R1001.2.
82. Termination. Chimneys shall extend at least 2' higher than any portion of the building within 10', but shall not be less
than 3'above the highest point where the chimney passes through the roof R1003.9.
83. Chimney clearances.Any portion of masonry chimney located in the interior of the building or within the exterior wall
of the building shall have a minimum air space clearance to combustibles of 2". Chimneys located entirely outside the
exterior walls of the building,including chimneys that pass through the soffit or cornice, shall have a minimum air space
clearance of 1".The air space shall not be filled,except to provide fire blocking in accordance with R1003.19,R1003.18.
84. Fireplace clearances. All wood beams, joists, studs and other combustible materials shall have a clearance of not less
than 2" from the front faces and sides of the masonry fireplace and not less than 4" from the back faces of masonry
fireplaces.The air space shall not be filled,except to provide fire blocking in accordance with R1001.12,R1001.11.
85. Chimney crickets. Chimney shall be provided with crickets when the dimension parallel to the ridgeline is greater than
30" and does not intersect the ridgeline. The intersection of the cricket and the chimney shall be flashed and counter
flashed in the same manner as normal roof-chimney intersections. Crickets shall be constructed in compliance with Figure
R1003.20 and Table RI003.20,R1003.20.
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86. Lintel and throat. Masonry over a fireplace opening shall be supported by a lintel of noncombustible material. The
minimum required bearing length on each end of the fireplace opening shall be 4".The fireplace throat or damper shall be
located a minimum of 8"above the lintel R1001.7.
87. Mantel and trim. Woodwork or other combustible materials shall not be placed within 6" of fireplace opening.
Combustible material within 12"of the fireplace opening shall not project more than 1/8"for each 1"distance from such
opening R1001.11,Exception 4.
88. Hearth and hearth extensions. Masonry fireplaces hearths and hearth extensions shall be constructed of concrete or
masonry, supported by noncombustible materials and reinforced to carry their own weight and all imposed loads. No
combustible material shall remain against the underside of hearths and hearth extensions after construction R1001.9.
89. Hearth thickness.The minimum thickness of fireplace hearths shall be 4"R1001.9.1.
90. Hearth extension dimensions. Hearth extensions shall extend at least 16"in front of,and at least 8"beyond each side
of the fireplace opening. Where the fireplace opening is 6 square feet or larger, the hearth extension shall extend at least
20"in front of,and at least 12"beyond each side of the fireplace opening R1001.10.
91. Exterior air. Factory-built or masonry fireplaces covered in Chapter 10 shall be equipped with an exterior air supply to
ensure proper fuel combustion unless the room is mechanically ventilated and controlled so that indoor pressure is neutral
or positive R1006.1.
92. Exterior air intake. The exterior air intake shall be capable of supplying all combustion air from the exterior of the
dwelling or from spaces within the dwelling ventilated with outside air such as non-mechanically ventilated crawl or attic
spaces.The exterior air intake shall not be located within the garage or basement of the dwelling nor shall the air intake be
located at an elevation higher than the firebox.The exterior air intake shall be covered with a corrosion-resistant screen of
1/4"mesh R1006.2.
MECHANICAL REQUIREMENTS
93. Listed and labeled. Appliances regulated by this code shall be listed and labeled for the application in which they are
installed and used,unless otherwise approved in accordance with R104.11,M1302.1.
94. Appliances access for inspection service, repair and replacement. Appliances shall be accessible for inspection,
service, repair and replacement without removing permanent construction, other appliances, or any piping or ducts not
connected to the appliance being inspected,serviced,repaired or replaced. A level working space at least 30"x 30" shall be
provided in front of the control side to service an appliance M1305.1.
95. Central furnaces. Central furnaces within compartments, alcoves or similar spaces shall conform to M1305.1.1 and
M1305.1.2.
96. Appliances in attics. Attics containing appliances requiring access shall be provided with an opening and a clear and
unobstructed passageway large enough to allow removal of the largest appliance,but not less than 30"high and 22"wide
and not more than 20'in length when measured along the centerline of the passageway from the opening to the appliance.
The passageway shall have continuous solid flooring not less than 24"wide. A level service space at least 30" x 30" shall
be present along all sides of the appliance where access is required. The clear access opening dimensions shall be a
minimum of 20"x 30"where such dimensions are large enough to allow removal of the largest appliance M1305.1.3.
EXCEPTIONS:
1. The passageway and level service space are not required where the appliance is capable of being serviced
while standing on a portable ladder extending through the required opening.
2. Where the passageway is unobstructed, and not less than 6' high and 22" wide for its entire length, and is
not more than 50'long.
3. In existing structures the access opening shall be large enough for removal and replacement of the largest
piece of the equipment.
97. Appliance clearance. Appliances shall be installed with the clearances from unprotected combustible materials as
indicated on the appliance label and in the manufacturer's installation instructions M1306.1.
98. General piping support. Where mechanical system piping support requirements are not specified in other sections of
this code,mechanical systems piping shall be supported in accordance with this section,M1309.1,and Table 1309.4.
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99. Installation. Heating and cooling equipment and appliances shall be installed in accordance with the manufacturer's
installation instructions and the requirements of this code. The equipment shall be sized based on building loads
calculated in accordance with ACCA Manual J,or other approved heating and cooling calculation methodologies,M1401.1
and M1401.3.
100. Outdoor discharge. The air removed by every mechanical exhaust system shall be discharged to the outdoors. Air shall
not be exhausted into an attic,soffit,ridge vent or crawlspace M1501.1.
EXCEPTION: Whole-house ventilation-type attic fans that discharge into the attic space of dwelling units
having private attics shall be permitted.
101. Range hoods general. Range hoods and down draft exhaust systems shall comply with the requirements of M1503.1,
M1503.2,M1503.3 and M1503.4.
102. Mechanical ventilation general. Where R303.3 requires toilet rooms, bathrooms and rooms with bathing or spa
facilities to be mechanically ventilated,the ventilation equipment shall be installed in accordance with M1507.1.
103. Recirculation of air. Exhaust air from range hoods, bathrooms, toilet rooms and rooms with bathing or spa facilities
shall not be recirculated within a residence or to another dwelling unit and shall be exhausted directly to the outdoors.
Exhaust air from range hoods,bathrooms,toilet rooms and rooms with bathing or spa facilities shall not discharge into an
attic,crawl space or other areas inside the building M1507.2.
104. Rooms with bathing and spa facilities. All rooms containing bathing or spa facilities shall be provided with a
mechanical ventilation system controlled by a dehumidistat,timer,or similar means of automatic control M1507.4.
105. Duct systems. Building cavities used for return air duct or plenums in new construction shall conform to M1601.1.1.1;
and for existing buildings,M1601.1.1.2.
106. Combustion air.Liquid and solid fuel-burning appliances shall be provided with a supply of air for fuel combustion,
draft hood dilution and ventilation of the space in which the appliance is installed,in accordance with M1702
andM1703,M1701.1.
ENERGY EFFICIENCY
107. All conditioned spaces within residential buildings shall comply with Table N1101.1(1)and one additional
measure from Table N1101.1(2).
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TABLE N1101.1(1)
PRESCRIPTIVE ENVELOPE REQUIREMENTS*
` 3
BUILDING COMPONENT STANDARD BASE CASE LOG HOMES ONLY
Required Performance Equiv.Valueb Required Performance Equiv.Valueb
Wall insulation-above grade U-0.060 R-215 d e
Wall insulation-below gradee F-0.565 R-15 F-0.565 R-15
Flat ceilings( U-0.031 R-38 U-0.025 R-49
Vaulted ceilinns8 U-0.042 R-388 U-0.027 R-38Ah
Underfloors U-0.028 R-30 U-0.028 R-30
Slab edgeyerimeter F-0.520 R-15 F-0.520 R-i5
Heated slab interior' n/a R-10 n/a R-10
Windows] U-0.35 1J-0.35 U-0.35 U-0.35
Window area limitation" n/a n/a n/a n/a
Skylights' U-0.60 U-0.60 U-0.60 U-0.60
Exterior doors"' U-0.20 U-0.20 U-0.54 U-0.54
Exterior doors w/>2.5 ft2 glazing" 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=0.093 m2,1 degree=0.0175 rad.
a.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-value standards.Calculations to document equivalent heat loss shall be performed using the procedure and approved U-values
contained in Table N1104.1(1).
b.R-values used in this table are nominal,for the insulation only in standard wood framed construction and not for the entire assembly.
c.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.R-
19 Advanced Framed or 2 x 4 wall with rigid insulation may be substituted if total nominal insulation R-value is 18.5 or greater.
d.The wall component shall be a minimum solid log or timber wall thickness of 3.5 inches(90 mm).
e.Below-graded 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 above grade.
f.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(13.9m2)in area may be reduced to not less than R-21.When reduced,the cavity shall be filled(except for required ventilation spaces).
g.The maximum vaulted ceiling surface area shall not be greater than 50 percent of the total heated space floor area unless area has a U-factor no greater than U-
0.031.The U-factor of 0.042 is representative of a vaulted scissor truss.A 10-inch deep rafter vaulted ceiling with R-30 insulation is U-0.033 and complies with
this requirement,not to exceed 50 percent of the total heated space floor area.
h.A=advanced frame construction,which shall provide full required insulating value to the outside of exterior walls.
i.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.
j.Sliding glass doors shall comply with window performance requirements.Windows exempt from testing in accordance with Section NF111.2 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 coating 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.
k.Reduced window area may not be used as a trade-off criterion for thermal performance of any component
1.Skylight area installed at 2%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 overhead plane per NFRC standards.
m.A maximum of 28 square feet(2.6m2)of exterior door area per dwelling unit can have a U-factor of 0.54 or less.
n.Glazing that is either double pane with low-e coating or one surface,or triple pane shall be deemed to comply with U-0.40 requirement.
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TABLE N1101.1(2)
•
ADDITIONAL MEASURES(select one)°
Measure
High efficiency HVAC system:
1 Gas-fired furnace or boiler with minimum AFUE of 90%a,or
Air-source heat pump with minimum HSPFof 8.5 or
Closed-loop ground source heat pump with minimum COP of 3.0
High efficiency duct sealing:
2 Certified performance tested duct systemsb or
All ducts and air handler are contained within building envelopes
High efficiency building envelope:
Replace corresponding Table N1101.1(1)components with all of the following:
3 Wall insulation-above grade U-0.0471 R-24 and
Vaulted ceilings—U-0.033/R-30Ac°,and
Flat ceilings—U-0.0251 R-49,and
Windows—U-0.32
Zonal electric,ductless furnace or ductless heat pumps:
75 percent of permanently installed lighting fixtures as CFL or linear fluorescent or a min efficacy of 40 lumens per watt,
4 or
Windows—U-0.32,or
Flat ceilings—U-0.025/R.-49 and vaulted ceilings-U-0.033/R-30A or
Exterior walls—U-0.047/R-24
High efficiency ceilings&windows/lighting:
Replace corresponding Table N1101.1(1)components with all of the following:
5 Vaulted ceilings—U-0.033/R-30A`.d,and
Flat ceilings—11-0.025/R-49,and
Windows—U-0.32,and
75 percent of permanently installed lighting fixtures as CFL or linear fluorescent or a min efficacy of 40 lumens per watt
High efficiency ceilings&windows/water heating:
Replace corresponding Table Ni 101.1(1)components with all of the following:
6 Vaulted ceilings—U-0.033/R-30Ac,a,and
Flat ceilings—U-0.025/R-49,and
Windows=-U-0.32,and
Natural gas/pro_pane,on-demand water heating with min EF of 0.80
High efficiency water heating/lighting:
7 Natural gas/propane,on-demand water heating with min EF of 0.80,and
75 percent of permanently installed lighting fixtures as CFL or linear fluorescent or a min.efficacy of 40 lumens per watt
8 Solar photovoltaic:
Minimum I watt/sq ft conditioned floor space3
9 Solar water heating:
Minimum of 40 ft2 of gross collector arear
For Si:I square foot=0.093 m2,1 watt per square foot=10.8 W/m2.
a.Furnaces located within the building envelope shall have sealed combustion air installed.Combustion air shall be ducted directly from the outdoors.
b. Documentation of Performance Tested Ductwork shall be submitted to the Building Official upon completion of work.This work shall be performed by a contrac-
tor that is certified by the Oregon Department of Energy's(ODOE)Residential Energy Tax Credit program and documentation shall be provided that work demon-
strates conformance to ODOE duct performance standards.
c. Advanced frame construction,which shall provide full required ceiling insulation value to the outside of exterior walls.
d.The maximum vaulted ceiling surface area shall not be greater than 50percentof the total heated space floor area unless vaulted area has a U-factor no greater than
U-0.026.
e. Solar electric system size shall include documentation indicating that Total Solar Resource Fraction is not less than 75%.
1. Solar water heating panels shall be Solar Rating and Certification Corporation(SRCC)Standard 0G-300 certified and labeled,with documentation indicating that
Total Solar Resource Fraction is not less than 75%.
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City of Tigard—2017 RESIDENTIAL CODE SUMMARY
EXTERIOR ENVELOPE REQUIREMENTS
• 108. Insulation materials. Insulation materials shall be installed per manufacturer's listing and specifications and this section.
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 N1104.2.
109. Loose-fill insulation. Blown, poured and spray-on type insulation complying with R316 may be used in attic spaces
where roof slope is 4 units vertical in 12 units horizontal(33.3%slope) or greater and there is at least 44" 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.)Adequate baffling of the vent opening shall be provided so as to deflect the incoming
air above the surface of the blown or poured insulation. Baffles shall be of weather-resistant, rigid material capable of
retaining the insulation and shall be in place at the time of framing inspection N1104.2.1.
110. Batt-type insulation.Batt-type insulation shall be installed flush against the warm side of the cavity insofar as practicable
N1104.2.2.
111. Insulation protection.Insulation exposed to the exterior shall be protected from physical and solar damage.N1104.2.3.
112. Clearances N1104.2.4.
Recessed light fixtures shall not be installed in cavities intended to be insulated.
EXCEPTION: Fixtures designed and labeled as suitable for being installed in direct contact with insulation; i.e.,
insulation coverage(IC)rated.
Thermal insulation shall not be installed within 3" of any metal chimney or gas vent that is not listed for insulation
clearances
$`; Thermal insulation shall not be installed in a manner that would obstruct openings required for attic ventilation.
1,: A permanent sleeve of fine wire mesh screen, sheet metal or other noncombustible material shall be installed to maintain
' the required clearances.
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 (44FR39938). For other insulation, see R316. Foam plastic shall be as
specified in R314.
k "
is
113. Recessed lighting fixtures. Recessed light fixtures installed within the building envelop shall meet one of the following
ktil requirements N1104.2.6.
Wit
1. Type IC rated, manufacture 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.
k
2. Type IC rated in accordance with ASTM E283 with not more than 2 cfm air movement from the conditioned space
to the ceiling cavity at 1.57 psi pressure (75Pa) difference and shall be labeled and the annular space between the
ceiling cutout and lighting fixture shall be sealed.
04, 3. Type IC rated installed inside a sealed box constructed from a minimum 1/2"gypsum wallboard or constructed from a
preformed polymeric vapor barrier,or other air-tight assembly manufactured for this purpose.
DOORS AND WINDOWS
l'�= 114. Air leakage requirement.All windows and doors must meet the air leakage requirements of N1104.8.
115. Sealing required. Exterior joints around window and doorframes, between wall cavities and windows or door frames,
between wall and foundation,between wall and roof,between wall panels,at penetrations of 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
i*: official N1104.8.2.
k .. 116. Exterior doors. Doors shall be tested according to the requirements of Section N1104.4. When calculating the energy
Elii
41
' performance of the exterior envelop,the area of doors shall be the actual unit size N1104.3.
EXCEPTIONS:
l z:
. ' 1. Unglazed doors that are not tested according to the requirements of N1104.4 shall be assigned a default U-value of
`1. ; 0.54.i-6,
i-..*,-,-;,.i.
.„.±.„...„.„,
wa,,,,, _
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City of Tigard—2017 RESIDENTIAL CODE SUMMARY
2. Sliding glass doors and swinging glass doors shall meet the specification for glazing and shall be treated as such.
3. Doors that incorporate glazed areas more than 2-1/2 square feet in area shall be considered windows.
Doors shall meet the air leakage requirements of N1104.8.
117. Windows.All windows installed in Oregon shall meet the requirements of Part 111,Fenestration Standard N1104.4.
1. Decorative or unique architectural feature glazing not exceeding 1% 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.
2. Glass block assemblies may use a U-factor of 0.51.
3. 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.
118. Thermal performance labeling.All windows shall have performance labels N1104.4.1 and N1104.4.2.
VAPOR BARRIERS
119. Vapor retarders. A 1-perm, dry cup rating vapor retarder shall be installed on the warm in winter side of all insulation
N1104.9.1.
EXCEPTIONS:
1. When insulation is installed in ceilings in an existing structure and ventilation is provided as specified in R806,a vapor
retarder need not be installed.
2. Below-grade walls are not required to have a vapor retarder.
3. Slab-on-grade floors need not have a warm-side vapor retarder.
120. 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 6-mil black polyethylene or other approved material of equivalent perm rating. Ground
cover shall be lapped 12" at all joints and cover the entire surface area extending full width and length of the crawl space
and turn 12" up the foundation wall. Ground cover of 6-mil polyethylene or an approved equal shall be installed on the
ground beneath concrete floor slabs located in conditioned spaces N1104.9.2.
SLAB-ON-GRADE FLOORS
121. 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" or downward to the bottom of the slab, then horizontally
beneath the slab for a minimum total distance of 24"N1104.7. /R506.2.3
EXCEPTION:For monolithic slabs,the insulation shall extend downward from the top of the slab to the bottom of the
thickened edge.
122. 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,N1104.7.1.
HVAC
123. Insulation of ducts. All new duct systems, or new portions thereof,exposed to unconditioned spaces shall be insulated
according to Table N1101.1 (1)N1105.2.
EXCEPTION:The replacement or addition of a furnace,air conditioner or heat pump shall not require existing ducts to
be insulated to current code.
124. HVAC controls. All heating,ventilating and air-conditioning systems shall be provided with controls as specified herein
N1105.3.
125. 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 where used to control heating
only and from 70°F to 85°F 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 and shall be capable of operating the system heating and cooling in sequence.It
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City of Tigard—2017 RESIDENTIAL CODE SUMMARY
shall be capable of providing a temperature range of at least 5°F within which the supply of heating and cooling energy to
• the zone is shut off or reduced to a minimum N1105.3.1.
126. '",r Humidity. If a hvac 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%. 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%,
N1105.3.2.
_ .", 127. Temperature zoning. Each separate hvac system shall be provided with 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 unconditioned basements and garages N1105.3.3.
lag
128. Setback and shutoff. The thermostat, or an alternate means such as a 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 N1105.3.4.
EXCEPTION:
1. Where it can be shown that setback or shutdown will not result in a decrease in overall building energy.
, " 2. Equipment with full load demand of 2 kilowatt(6.826 Btu/h) or less may be controlled by readily accessible off-hour
controls.
t Lowering thermostat set points to reduce energy consumption of the heating system shall not cause energy to be
:, expended to reach the reduced setting.
? 129. Heat pump controls. All heat pump system thermostats shall be capable of manual setback and limiting the use of
41 supplemental heat during warm-up periods NI 105.3.4.1.
130.,:;;;1- Outdoor thermostat required. The cut-on temperature for the compression heating shall be higher than the cut-on
temperature for the supplementary heat and the cut-off temperature for the compression heating shall be higher than thecut-off temperature for the supplementary heat N1105.3.4.1.1.
131. Outside combustion air. See R1006 for required outside combustion air for masonry fireplaces, factory-built fireplaces
.J and factory-built stoves N1105.4.
'14-1- LIGHTING
132. High-efficiency lighting systems.A minimum of 50%of the permanently installed lighting fixtures shall be compactor
linear fluorescent, or a lighting source that has a minimum efficacy of 40 lumens per input watt. Screw-in M compact
"' florescent lamps comply with this requirement.
CARBON MONOXIDE ALARMS
133. For new construction. Approved single station carbon monoxide alarms or a household carbon monoxide detection
system shall be installed.R315.1
134. Where required in existing dwellings. Where a new carbon monoxide source is introduced or work requiring a
structural permit occurs in existing dwellings,carbon monoxide alarms shall be provided.R315.5
RADON CONTROL
135. For new construction. New residential buildings will be required to mitigate radon entry as provided for in Appendix
Chap F
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