Chapter 6 BUILDINGS AND BUILDING REGULATIONS*
Section 6-66 Amendments.
The code adopted by this article is hereby amended by substituting the following
lieu of those sections with corresponding numbers in the code, or, where there is no
corresponding section in the code, the following sections shall be enacted as additions to the
R101.1 Title: These provisions shall be known as the Residential Code for One- and Two-Family
Dwellings of the City of Columbia, and shall be cited as such and will be referred to
herein as this code.
R102.5.1 Appendices A, B, C, E,
G, H, K and N are hereby adopted as published.
R103.1 Creation of enforcement agency: Delete in its entirety.
R103.2 General: The building official is hereby authorized and directed to administer and
enforce all provisions of this code. The building official shall be the director of community
R104.10.1 Flood Hazard Areas: Delete in its entirety.
R105.1 Permits required. Add to paragraph: All building, electrical, plumbing, mechanical and
fuel gas permits may be issued to the general contractor, on behalf of master electrical, master
mechanical, and master plumbing contractors, for new one- and two-family dwellings and
building alteration or building additions to one- and two-family dwellings. All electrical,
mechanical, plumbing and fuel gas work must be performed by trade contractors licensed by the
City of Columbia for the appropriate trade or as allowed by ordinance.
R105.2, No. 2: Fences not over twelve (12) feet high.
R220.127.116.11 Elevation Documentation: Deleted.
R112.1 General: Any aggrieved person shall have the right to appeal a decision of the building
official to the building construction codes commission. Applications for appeal shall be filed
accordance with the procedures set out in Section 113 of the Building Code of Columbia,
R112.2.1 Determination of substantial improvements in areas prone to flood: Delete in its
R112.2.2 Criteria for issuance of a variance for areas prone to flooding: Delete in its entirety.
R112.3 Qualifications: Delete in its entirety.
R113.4 Violation penalties: Any person who shall violate a provision of this code or shall fail
comply with any of the requirements thereof, shall be guilty of a misdemeanor and upon
conviction thereof, shall be punished by a fine of not more than one thousand dollars ($1,000.00)
or by imprisonment not exceeding one (1) year, or by both such fine and imprisonment. Each
day that a violation continues shall be deemed a separate offense.
R202 Definitions: Accessory Structure. A structure not greater than three thousand (3,000)
square feet (279m) in floor area, and not over three (3) stories or exceeding twenty-four (24) feet
in height with separate means of egress, and shall not occupy more than thirty percent (30%) of
the required rear yard, and shall not exceed the height of the main structure, the use of which is
customarily accessory to and incidental to that of the dwelling(s) and which is located on the
R202: Add: Attic, Habitable. Add: 4. The occupiable space is provided with an egress door
accordance with Section R311.2 or by a ramp in accordance with Section R311.8 or a stairway in
accordance with Section R311.7.
Table 301.2 (1): The following values shall be inserted into Table R301.2 (1):
Ground Snow Load 20; Wind Speed (mph) 90; Topographic Effects No, Weathering -
Severe; Frost Line Depth Yes; 30-inches; Termite - Moderate to Heavy; Winter Design
Temperature - +4 Degrees Fahrenheit; Ice Barrier Underlayment Required No; Flood Hazards -
As regulated by City of Columbia Ordinance; Air Freezing Index - 0 to 1000; Mean Annual
Temperature - 55 degrees Fahrenheit.
Table R301.5: Add note g.4. Must also include a vertical egress component.
R302.1 Exterior walls: Add exception # 6: A detached accessory garage or shed located not less
than three (3) feet from any side lot line.
R302.2 Townhouses: Change exception to read: A common two (2) hour fire-resistance-rated
wall assembly tested in accordance with ASTM E 119 or Ul 263 is permitted for townhouses if
such walls do not contain plumbing or mechanical equipment, ducts or vents in the cavity of the
common wall. The wall shall be rated for fire exposure from both sides and shall extend to and
be tight against exterior walls and the underside of the roof sheathing. Electrical installations
shall be installed in accordance with Chapters 34 through 43. Penetrations of electrical outlet
boxes shall be in accordance with Section R302.4.
R302.5.1 Delete "equipped with a self-closing device."
R302.6 Dwelling/garage fire separation: Replace one-half (½) inch gypsum board with five-eighth
(5/8) inch gypsum board in referenced Table R302.6 Dwelling/garage fire separation. Add
last sentence to paragraph of R302.6: The garage shall be completely separated from the
residence and its attic area by means of five-eighth (5/8) inch gypsum board or equivalent
applied to the garage side.
R303.4 Mechanical ventilation. The dwelling unit shall be provided with whole-house
mechanical ventilation in accordance with Section M1507.3. Alternatively, an insulated duct
from the outside connected to the return air or HVAC unit ahead of the filter with balancing
damper may be provided. The duct size shall be based on the conditioned area the HVAC unit
serves. The duct shall be four (4) inch diameter for areas 1,500 S.F. or less, six (6) inch diameter
for areas over 1,500 S.F. and less than or equal to 2,400 S.F., and eight (8) inch diameter for
areas over 2,400 S.F.
R303.6 Add Exception: Bathroom exhaust fans may be exhausted into a soffit vent if composed
of approved materials as determined by the building official.
R307.3 Water closet: All water closets shall be spaced at least fifteen (15) inches from the
centerline of the fixture to any wall or plumbing fixture, except the centerline of the water closet
may be spaced twelve (12) inches if located next to a bathtub.
R318.104.22.168 Risers: Change the first sentence to read: The maximum riser height shall be seven
and seven-eighth (7-7/8) inches (200mm). The rest of the paragraph remains as stated.
R322.214.171.124 Risers: Add Exception: Closed risers are not required on exterior stairs where
riser is less than ten (10) feet above grade.
R312.1.1 Where Required: Add: Grassed or landscaped areas a minimum of three (3) feet wide
behind a retaining wall shall not be deemed a walking surface.
R312.2 Deleted in its entirety.
R313.1 Townhouse automatic fire sprinkler systems. Delete in its entirety.
R313.2 One- and two-family dwelling automatic fire sprinkler systems. Delete in its entirety.
R313.3 Automatic Fire Sprinkler Systems: A builder of a single-family dwelling or residences or
multi-unit dwellings of four (4) or fewer units shall offer to any purchaser on or before the time
of entering into the purchase contract the option at the purchasers cost to install or equip an
automatic fire sprinkler system in the dwelling, residence, or unit. Not withstanding any other
provision of law to the contrary, no purchaser of such a single-family dwelling, residence, or
multi-unit dwelling shall be denied the right to choose or decline to install an automatic fire
sprinkler system in such dwelling or residence being purchased by any code, ordinance, rule,
regulation, order or resolution by any county or other political subdivision. Pursuant to Section
67.281 RSMo, the mandatory option for purchasers to have the right to choose and the
requirement that the builders offer to purchasers the option to purchase an automatic fire
sprinkler system in connection with the purchase of any single-family dwelling, residence, or
multi-unit dwelling of four (4) or fewer units is hereby incorporated into the code.
R322.1 General: Section 29-22 of the Code of Ordinances applies. Delete the rest of section
R322 Flood-Resistant Construction in its entirety.
R401.1 Application: Add Exception: Foundation repairs for one- and two-family dwellings
shall not require geotechnical evaluation or structural calculations.
Table R401.4.1 PRESUMPTIVE LOAD-BEARING VALUES OF FOUNDATION
MATERIALS: Load-Bearing pressure (pounds per square foot) column, change value for clay,
sandy clay, silty clay, clayey silt, silt and sandy silt (CL, ML, MH, and CH) from 1,500 to 2,000
leaving footnote b.
Figure R403.1(1) Concrete and Masonry foundation details: A monolithic slab with integral
footing shall have the following: a #4 reinforcement bar spaced a minimum of forty-eight (48)
inches on centers to provide connection of footing to slab. The vertical rods shall extend to
within four (4) inches of the bottom of the footing and be turned to provide a horizontal leg that
extends a minimum of twelve (12) inches into the slab.
R403.3 Frost-protected shallow foundations: Delete in its entirety.
R404.1 Concrete and masonry foundation walls: Add additional paragraph: Drawings showing
options labeled as drawing 1.1, 1.2, 1.3, 1.4, 2.1, 2.2, 3.1 and 3.2 are intended to be alternative
methods to comply with lateral support of foundation walls and subsections for connection of
foundation to floor; and option labeled as drawing 4 is intended to be in compliance with
subsections for reinforcement in walls and connection of foundation walls to floor.
NOTE: Drawings as stated above are on file in the office of the building official.
R404.4 Retaining Walls: Change twenty-four (24) inches (610 mm) to read forty-eight (48)
inches (1219 mm); rest of paragraph remains as stated.
R405.1 Concrete or masonry foundations. Drains shall be provided around all concrete or
masonry foundations that retain earth and enclose habitable or usable spaces located below
grade. Drainage tiles, gravel or crushed stone drains, shall be installed at or below the area
protected and shall discharge by gravity or mechanical means into an approved drainage system.
Gravel or crushed stone drains shall extend at least one (1) foot (305 mm) beyond the outside
edge of the footing and six (6) inches (152 mm) above the top of the footing and be covered with
an approved filter membrane material and shall include a drain tile pipe surrounded with an
approved filter membrane or the filter membrane shall cover the washed gravel or crushed rock
covering the drain as shown in figure R405.1. The drain pipe can be placed directly on top of
footing. The top of open joints of the drainage tiles or perforated pipe shall be protected with
strips of building paper, and the drainage tiles or perforated pipe shall be placed directly on the
top of the footing or placed on a minimum of two (2) inches (51 mm) of washed gravel or
crushed rock at least one size larger than the tile joint opening or perforation and covered with
not less than six (6) inches (152 mm) of the same material. Foundation Drainage Figure R405.1
as adopted, shall be considered to satisfy the provisions of this subsection.
NOTE: Foundation Figure R405.1 as stated above, is on file in the office of the building
R802.3.1 Ceiling joist and rafter connections: Add last sentence to second paragraph: Rafter
ties shall be spaced not more than four (4) feet (1219 mm) on center.
M1501.1 Outdoor discharge: List first exception as number 1. and add exception number 2.: Air
may be exhausted into a soffit vent if composed of approved materials as determined by the
M1507.2 Recirculation of air: Add exception: Air may be exhausted into a soffit vent if
composed of approved materials as determined by the building official.
M2103.2.2 Suspended floor installation. Add exception: For direct contact plate systems, no
insulation is required as long as space below is habitable.
G2414.5.2 Copper tubing: Replace second paragraph with: Copper pipe and copper tubing shall
not be allowed for fuel gas piping systems.
G2415.14 Add to last sentence: Any underground gas piping allowed by this section shall only
be approved for gas that is less dense than the atmospheric pressure and shall be installed in
accordance with G2415.12.1.
G2415.14.2 Delete in its entirety.
G2417.4.1 Test pressure: The test pressure to be used shall be not less than one and one-half
(1.5) times the proposed maximum working pressure, but not less than thirty (30) psig,
irrespective of design pressure. (Rest of section remains as stated.)
G2419.4 Sediment trap. Change "any length" to "three and one-half (3½) inch
P2602.1.1 Individual water supply: Where a potable public water supply is not available,
individual sources of potable water supply shall be utilized.
P2602.1.2 Availability: A potable public water supply system shall be considered available to a
building when any portion of the property is located within two hundred twenty-five (225) feet of
the public water main.
P2603.2.1 Protection against physical damage: Delete.
P2603.4: Add the following: Alternatively, the sleeve may be sized in accordance with the
sealing system manufacturer's published recommendations.
P2603.5 Freezing: A water, soil or waste pipe shall not be installed outside of a building, or
concealed in outside walls, or in any place subjected to freezing temperature, unless adequate
provision is made to protect such pipe from freezing by insulation, heat or both. Water pipes
shall not be installed in an exterior wall cavity in one and two family dwellings. For purposes of
this section exterior wall cavities shall mean all walls that rain can fall upon. Water service
piping shall be installed below recorded frost penetration but not less than thirty (30) inches
P2603.5.1 Sewer depth: Is amended to read: Building sewers that connect to private sewage
disposal systems shall be a minimum of thirty (30) inches below finished grade at the point of
septic tank connection. Building sewers shall be a minimum of thirty (30) inches below grade.
P2604.3 Backfilling: Delete last sentence from section which reads: Loose earth shall be
carefully placed in the trench in six (6) inch (152mm) layers and tamped in place.
P2705.1 #5 Water closets, lavatories and bidets: Amend first sentence to read: All water closets
shall be spaced fifteen (15) inches from the centerline of the fixture to any wall or plumbing
fixture except the centerline of the water closet may be spaced twelve (12) inches is located next
to the bathtub. Rest of the paragraph remains as stated.
P2903.5 Water hammer: Add exception: A water-hammer arrestor is not needed in water
distribution systems using PEX piping or systems using a combination of PEX and copper.
P2905.4 Water service pipe: Where this section references one hundred sixty (160) pounds per
square inch replace with two hundred (200) pounds per square inch.
P2905.9.1.3 PVC plastic pipe. A primer that conforms to ASTM F 656 shall be applied to PVC
solvent-cemented joints. Purple primer shall be used below grade. Solvent cement for PVC
plastic pipe conforming to ASTM D 2564 shall be applied to all joint surfaces. If purple primer
is used, Section P2503 Inspections and Tests shall not be required.
P3005.2.4 Change of direction: Cleanouts shall be installed at each fitting with a change of
direction more than 45 degrees (0.79 rad) horizontal to horizontal in the building sewer, (rest of
paragraph remains as stated).
P3008.1 Sewage backflow. Delete last sentence.
P3111.1 Type of fixtures: Add exception: Residential food waste grinders shall be allowed to
discharge into a combination waste and vent system provided an air admittance valve is installed.
P3113.1 Size of vents: Add sentence to paragraph: At least one (1) vent shall be three (3) inch
unreduced in size extending from the main building drain through the roof.
P3201.2 Trap seals and trap seal protection: Delete.
Except as stated in sections E3608.1.1 Exception, E3609.6.1 and E3609.7 of this ordinance,
Chapters 34 through 43 of the 2012 International Residential Code are superseded by the
requirements as stated in the 2011 National Electrical Code (NFPA 70-2011).
E3608.1.1 Exception: When a concrete-encased electrode and/or ground ring are not available
for use in a grounding electrode system, a rod or other electrode as specified in E3608.1.4 Rod
and pipe electrodes and 3608.1.5 Plate electrodes can be used as a substitute. The second rod
electrode shall not be connected in series with the first rod electrode except where there exists a
metal water pipe in contact with earth for ten (10) feet or more, for one- and two-family
dwellings a single grounding electrode placed at the outside of the building at the nearest point of
the service disconnect shall be permitted to fill the requirements of this section.
E3609.6.1 Water Heater Bonding Jumper: The interior metal water piping bonding shall include
a bonding jumper between the hot and cold waterlines at the water heater fixture if the entire
system is copper excluding the service.
E3609.7 Bonding other metal piping: Delete including gas piping from section.
Appendix F, Radon Control Methods, Section AF101 Scope, AF101.1 General: Is amended
read: This appendix contains requirements for new construction and shall apply without regard
to zone designation in Figure AF101 and Table AF101(1).
Appendix F, Radon Control Methods, is amended by deleting subsection AF103.12 Power
Source in its entirety.
Appendix G, Swimming Pools, Spas and Hot Tubs, section AG105.2 Outdoor swimming pool:
An outdoor swimming pool, including an in-ground, above-ground pool, hot tub or spa shall be
surrounded by a barrier which shall comply with the following:
1. The top of the barrier shall be at least seventy-two (72) inches (1836 mm)
ground level measured on the side of the barrier which faces away from the swimming pool. The
maximum vertical clearance between finished ground level and the barrier shall be two (2) inches
(51 mm) measured on the side of the barrier which faces away from the swimming pool. Where
the top of the pool structure is above grade, such as an above ground pool, the barrier may be at
ground level, such as the pool structure, or mounted on top of the pool structure. Where the
barrier is mounted on top of the pool structure, the maximum vertical clearance between the top
of the pool structure and the bottom of the barrier shall be four (4) inches (102mm).
Exception: The top of the barrier shall be at least forty-eight (48) inches (1219 mm) above
ground level measured on the side of the barrier which faces away from the swimming pool
provided the swimming pool is equipped with a rigid safety cover complying with ASTM F
2. through 10. Same as stated in International Residential Code.
(Ord. No. 14119 § 1, 7-5-94; Ord. No. 15397, § 1, 10-20-97; Ord. No. 15629,
§ 1, 6-1-98; Ord.
No. 17501, § 1, 11-4-02; Ord. No. 19355, § 1, 1-2-07; Ord. No. 19767, § 1, 12-17-07;
20910, § 1, 3-21-11;
Ord. No. 21808, § 1, 9-16-13; Ord. No. 21940, § 1, 1-6-14
(Ord. 21940, Amended, 01/06/2014, Prior Text; Ord. 21808, Amended, 09/16/2013, Prior Text; Ord. 21095, Amended, 09/22/2011, Prior Text; Ord. 20910, Amended, 03/21/2011, Prior Text; Ord. 19767, Amended, 12/17/2007, Prior Text; Ord. 19355, Amended, 01/02/2007, Prior Text; Ord. 17501, Amended, 11/04/2002, Prior Text; 15629, Amended, 06/01/1998, Prior Text)