Code Comparison

HUD Code
(Federal Manufactured Home Construction and Safety Standards – 24 CFR 3280)
vs.
ORSC Code 
(2011 Oregon Residential Specialty Code)

Design Element HUD
Manufactured Housing Standards
Oregon Residential
Code with OR Amendments***
FIRE SAFETY
Exit doors Two @ 28 in (min) width
Must be 20 ft apart (12 ft on single section home)
3280.105 (a) & (2)
One @ 32 in width
R  311.2
Specific exit door location relationship to bedrooms Yes
3280.105
None
Window height in bedroom
from floor to opening of window
36 in (max)
3280.106(b)
44 in (max)
R  310.1
Bedroom egress window opening size 24 in (min) high clear opening
20 in (min) width clear opening
24 in (min) high clear opening
20 in (min) width clear opening
R 310.1.2 & 310.1.3
Required window area 5 sq ft (min) All egress openings min. 5.7 sq. ft.
R 310.1.1
Hallways 28 in wide (min)
3280.112
36 in wide
R 311.6
Smoke Alarms Yes
3280.208(b)
Yes
R 314.1
Carbon Monoxide Alarm None YesR 315
Flame spread
Walls 200 flame spread rating
3280.203(1)
200 flame spread rating
R 302.9.1
Ceilings 75 flame spread rating
3280.203(2)
200 flame spread rating
R 315.1
Furnace, water heater & cooking area Special protection with gypsum
25 flame spread
3280.203(3)
Minimum clearances specified
Lesser clearance allowed with protective materials, unless under a stairway
Flame spread of plastic bathtubs, shower units and tub or shower doors 200 flame spread rating
3280.203(6)
Shall comply with ANSE
Z 124.1-95 & 124.2-95
ELECTRICAL
Requirements based on National Electric Code Yes
3280.801 NEC NFPA 70 2005
Yes
NEC NFPA 70 2008
Required listed materials and devices Yes
3280.801(d)
Yes
NEC 110.2
Aluminum wire in branch circuits Not permitted
3280.801(e)
Permitted
NEC 310.2(b)
Receptacle location Comparable
3280.806
Comparable
NEC 210.52-210.63
Load Circulations Comparable
3280.804
Comparable
NEC 210.23
Separate neutral and ground circuits on branch circuit wiring and panel board(s) for range and dryer Yes
3280.806
Yes
NEC 220.52 (a & b)
Electric disconnecting means required at panel board Yes No
Single disconnecting means required at sub-panel board Yes No
Tests required on all parts Yes
3280.810
No
NEC 550.17
PLUMBING
Water supply piping Plastic allowed (CPVC or PEX)
3280.604
Plastic allowed (CPVC or PEX)
UPC 301.1.1
Drain-waste-vent piping Plastic allowed (PVC or ABS)
3280.610
Plastic allowed
OPSC 701.1
Venting of plumbing fixtures Wet venting and anti-siphon (mechanical vents) permitted in addition to required direct venting
3280.611(2 & 3)
Wet venting permitted only for fixtures located vertically above lower fixture
in the same story
OPSC 908.1
Material National accepted standards
3280.603
National accepted standards and Building Official approvals
OPSC 301.2
Test and inspections Water systems, drainage and
fixtures are tested
3280.612
Water systems, drainage vent
systems and fixtures are tested
OPSC 103.5.1
STRUCTURAL DESIGN
Moisture in framing lumber Kiln dried lumber required 19% max. moisture content  3280.304 Green lumber permitted
R 318.2 (19% max if interior
finish is applied)
Roof live load 20 PSF (min) Depends on design zone
3280.305 (4)(c)
25 PSF (min) Depends on
county and elevation
Table R 301.2(1)
Wind load (horizontal) 15 PSF (min) Depends on design zone
3280.305
15 PSF (min)  Depends on design zone and exposure
R 301.2(1)
Wind load (vertical) 9 PSF (min) Depends on design zone
3280.305
20 PSF (min)
Table R 301.2(2)
Floor live load 40 PSF
3280.305 (g)
40 PSF (min) Dwelling area
30 PSF Sleeping rooms
Table 301.5
Horizontal load on interior walls 5 PSF
3280.305 (f)(2)
See Chapter 6
Roof trusses Engineered and Tested Engineered only
R 802.10.2
LOAD DEFLECTION
Floors L/240 Span (max)
3280.305
1/360 Span (max)
Table R 502.3.1 (1 & 2) & TR301.7
Roof and ceiling L/180 Span (max)
3280.305
1/240 Span (max)
Table R 802.4.1 or  TR301.7
Walls L/180 Span (max)
3280.305
L/120 Span (max)
Table R 301.7
Plans and Specifications Engineered
3280.303 (B)
Layman-if using conventional framing methods
R 106 (Const. Doc.)
ARCHITECTURAL DESIGN BUILDING PLANNING
Minimum Room Sizes
One living area 150 square feet
3280.109 (a)
120 square feet
R 304.1
Double bedroom 70 square feet
3280.109.2
70 square feet
R 304.2
Single bedroom 50 square feet
3280.109.2
70 square feet
R 304.2
Room width 5 ft (min)
3280.110
7 ft (min)
R 304.3
Room height 7 ft 0 in (min) (exceptions)
3280.104
7 ft 0 in. (min)
R 305.1
Hallway height 6 ft 6 in (min)
3280.104(b)
7 ft. 0 in. (min)
R 305.1
Closet depth 22 in (min)
3280.109(c)
Not specified
Light and Ventilation
Glazed area 8% (min) gross floor area of room
3280.103(a)
8% of habitable room floor area
R 303.1
Ventilation area 4% (min) gross floor area of room
3280.103(b)
4% (min) gross floor area of room
R 303.1
Mechanical Habitable; .35 air changes per hour
3280.103(b)
Mechanical ventilation (optional)
0.35 air changes per hour
R 303.1 except #1
Ventilation Bath 50 cfm
3280.103(C)(3)
Bath 50 cfm
Table 1506.3 & MI507.3
Ventilation to improve indoor air quality above minimum standard Required 15cfm per occupant R 303.1 except #1
Formaldehyde emission control Required Not specified
Attic Ventilation
Fraction of floor area 1/300 (min)
3280.504(c)
1/150 (min) reduction possible
R 806.2
THERMAL ENERGY CONSERVATION
Moisture control (vapor barrier) Yes
3280.504 (all)
Yes
R 1104.9
Walls Yes
3280.504(b)
Yes
R 1104.1
Ceiling Yes
3280.504(a)
Variable
R 1104.1
Floor Specified
3280.504
Yes
R 1104.1
Air infiltration control Specified
3280.505
Specified
R 1104.8
Double glazing or storm windows Specified R 1104.1
Design basis for heating (winter) 70 F (max)
3280.506 & 3280.510
Standard
R 1103.1
Thermal insulations Performance standard Prescriptive or thermal performance
R 1104
Foam plastic insulation restrictions Yes R 316

Building Code Comparison of Single Family Homes
(Revised 2011)