Building Codes for a Finished Concrete Basement — The Concrete Network

Building Codes for a Finished Concrete Basement - The Concrete Network

Sample Code Requirements for Finished Concrete Basements

NOTE: The following information is supplied as a guideline of what MAY BE ENCOUNTERED as far as local building codes are concerned. It is meant as a GUIDELINE ONLY. Actual building codes may vary greatly depending upon region, state and city.

The following requirements are meant as a guideline, which may apply to most simple residential basement finishing projects. However, a plan reviewer may determine that unusual circumstances dictate the need for additional information on any particular project. It should also be emphasized that especially on interior renovation projects many code requirements are verified through the inspection process and are not necessarily reflected within the approved plan documents

Habitable Room Sizes & Ceiling Heights

Habitable rooms shall have an area of no less than 70 s.f. and shall not be less than 7 feet in any dimension. Habitable rooms, bathrooms, hallways, and laundry rooms shall have a minimum ceiling height of 7′-0. Finished box-outs for structural or decorative beams, ductwork, plumbing and electrical systems shall have a minimum clearance of 6′-6, with a spacing of not less than 4′-0 on center.

Insulation, Partitions & Walls

Concrete foundation walls in finished rooms/areas shall be furred out and insulated with a minimum of R-8 insulation extending down to the basement floor slab on basement walls less than 50% above grade and a minimum of R-13 insulation on basement walls that are more than 50% above grade.


Basements having concrete foundation walls with less than 20% exposure above finished grade (based on height of wall times basement perimeter excluding unheated basement garages) may be uninsulated walls.

Wall Construction

Indicate size and spacing of new partition studs and finish wall material.

Approved water-resistant gypsum backer board is required in bathtub and shower areas.

Interior finish materials shall not have a flame spread rating exceeding 200.

Studs may be utility grade or better. Stud spacing shall be per TABLE 1, shall have a pressure treated bottom plate and can have a single or double top plate.

Studs in non-loadbearing walls may be notched to a depth not to exceed 40 percent of a single stud width. Studs may be bored or drilled, provided that the diameter of the resulting hole is no greater than 40 percent of the stud width, the edge of the hole is no closer than 5/8 inch to the edge of the stud, and the hole is not located in the same section as a cut or notch.

A single flat 2×4 member may be used as a header in interior nonbearing walls for openings up to 8 feet in width if the wall above is not more than 24 inches.

Natural Light and Ventilation, Safety Glazing for Concrete Basements

Show all new and existing window locations and indicate the overall glass size and ventilation area for each. For proposed bedrooms indicate the sill height, clear opening width, and clear opening height for the required emergency escape window. Glass area in habitable rooms shall not be less than 8% of floor area served. One-half of this area must be available for unobstructed ventilation with screens included. Artificial lights and/or mechanical ventilation (see ventilation section) may be used as an alternative if the existing windows are of inadequate size. Remaining unfinished rooms/areas shall have windows with unobstructed ventilation area equal to 1% of the floor area served or artificial ventilation in the amount of .05 CFM/s.f. of area. All bedrooms must have one window for emergency escape meeting the following minimums:

Maximum opening height — 44 Minimum clear opening width 20Minimum clear opening height — 24 Minimum clear opening area 5.0 s.f.

The emergency escape window shall be operable from the inside without the use of special knowledge, tool, or extra force, beyond that required for normal window operation.

Glazing in doors intended for human passage, patio doors, windows within 24 of a door, and shower and bathtub enclosure walls, panels or doors, shall be fully tempered, laminated safety, approved wired glass or approved shatter-resistant plastic.

Basement Stairways

Existing stairways may need to be modified with new solid risers or toe board, with possibly new replacement treads having nosings (when solid risers are provided), with new graspable handrails, and/or with new intermediate balusters for open stair guards to meet current code requirements.

Guards along open-sided stairs shall be a minimum of 34 in height above the leading edge of the tread and minimum of 36 in height at the stair landings. Open guards shall have intermediate vertical balusters spaced less than 4 apart. Horizontal rails, rails parallel to stair treads, and ornamental patterns that provide a ladder effect are prohibited on stairs from finished basement areas.

Ceiling/Floor Draftstopping, Firestopping, Smoke Detectors

Dropped ceilings below wood joists or attached directly to wood floor trusses shall be draftstopped with drywall or 3/8 plywood at 500 s.f. intervals and parallel to framing members.

Firestopping consisting of 2 lumber, minimum 23/32 structural panel, or approved non-combustible materials shall be provided at the ceiling line in concealed spaces of stud walls/partitions, including furred or studded-off spaces of concrete foundation walls and at soffits, dropped ceilings and similar spaces.

An AC powered, UL listed smoke detector with battery backup shall be located in the vicinity of all bedroom entrance doors and inside each bedroom. Provide a minimum of one AC powered UL listed smoke detector with battery backup at the bottom of the stair for basements without bedrooms.

All detectors within the house shall be interconnected so that the activation of any alarm will sound all alarms throughout the house.

Bedroom Emergency Egress

Note: most municipalities require a plan submission for all finished basements with a bedroom.

Every bedroom shall have at least one operable window or exterior door approved for emergency egress or rescue. The units must be operable from the inside to a full clear opening without the use of a key or tool.

Where windows are provided as a means of egress or rescue they shall have a sill height of not more than 44 inches, a minimum net clear opening of 5 s.f. a minimum net clear opening height of 22 inches and a minimum net clear opening width of 20 inches.

Where emergency egress windows exit to a window well, the minimum area dimensions of that window well shall be equal to 3 feet by 5 feet.

Air Ventilation Systems Concrete Basements

Show location of existing furnace and main supply and return ducts. Indicate location and sizes of any new sub-ducts, register and diffuser locations for the finished area. Detail any artificial ventilation that may be proposed for any room/space, such as for new or downsized furnace rooms, bathrooms or any finished room that does not have adequate windows for natural ventilation.

Appliances and equipment, such as furnaces and hot water heaters, must remain accessible for inspection, service, repair and replacement without removing permanent construction. The furnace room shall have an opening or door large enough to permit removal of the largest piece of equipment, but not less than 20 inches wide. An unobstructed working space not less than 30 inches wide and not less than 30 inches high shall be provided along the control side of the equipment when the door of the furnace room is open.

Fuel-burning appliances shall be supplied with combustion air. Furnace rooms must be provided with two permanent openings to adjacent spaces; one shall be located within 12 inches of the top and one within 12 inches from the bottom of the adjoining wall. Each opening shall have free area equal to a minimum of 1 square inch per 1,000 Btu/h input rating of all appliances installed within the furnace room, but not less than 100 square inches. The openings are not required if a louvered door is provided or the furnace room area is greater than 50 cubic feet per 1,000 Btu/h input rating of all appliances installed in the room.

Using inside air:

1 shall be provided/1000 BTU/hr. each opening. Openings shall not be less than 100 One opening shall be provided within 12 of the ceiling and within 12 above finished floor, no common ducts.

Using outside air:

  1. Horizontal openings

1 sq. in./2000 BTU/hr. for ducted opening

1 sq. in./4000 BTU/hr. for direct opening

  • Vertical openings

    1 sq. in./4000 BTU ducted or direct

  • Minimum clearance from combustibles is 18 inches, unless the listed manufacturer’s installation instructions allow an alternate clearance dimension. 18 inches of clearance is required at the front of the appliance for service.

    Clothes dryers shall be independent of all other system, and exhaust to the exterior.

    Building Codes for a Finished Concrete Basement - The Concrete Network

    Residential bathrooms without windows for natural ventilation shall exhaust 50 CFM minimum to the exterior. It is not permissible to discharge exhaust to the attic or floor joist area.


    Half-baths without a tub or shower may exhaust to the attic.

    For finished rooms without adequate windows, outdoor air (artificial ventilation) shall be supplied at a rate of 0.35 air changes per hour or 15 cubic feet per minute per person, whichever is greater. The estimated occupant load to be used for a large common room/space such as a recreation room or a rathskeller shall be based on 2 for the first bedroom and 1 for each additional bedroom within the house.

    Gas piping shall be identified at intervals of no more than 25′ when placed in concealed locations.

    Concrete Basement Electrical

    Show location and size of electrical panel (if new) and location of all new receptacles, lights, ceiling fans, exhaust fans and switches on the floor plans or indicate as a performance specification. Identify all 240-volt receptacles/circuits. Indicate which light and/or switches control receptacles. If proposed, show baseboard heater locations.

    The dimension of the working space in the direction of access to panelboards shall not be less than 36 inches in depth and 30 inches in width. The workspace shall be clear and shall extend from the floor or platform to a height of 6 feet 6 inches. In all cases, the workspace shall allow at least a 90-degree opening of panel doors or hinged parts. A dedicated space directly over a panelboard that extends from the panelboard to the ceiling shall be kept clear of unrelated equipment. This required workspace shall not be designated for storage. Panelboards shall not be located in closets or bathrooms.

    Ground fault circuit interrupters are required for receptacles and/or circuits installed in the following locations:

    • Bathrooms
    • Unfinished basement spaces except for laundry circuit and single receptacle dedicated to sump pumps.
    • Receptacles to serve counter top surfaces within 6′ of a wet bar.

    Receptacles are required to be installed in the following areas:

    • In all habitable rooms except bathrooms so that no space along a wall is more than 6′ from a receptacle.
    • All wall areas 2′ wide or greater required receptacles.
    • In hallways of 10′ or more in length.
    • In bathrooms installed adjacent to the basin.
    • At least one receptacle in laundry area and at least one receptacle in basement unfinished area in addition to the laundry receptacle.

    Lighting is required in the following areas:

    • At least one wall switched lighting outlet shall be installed in every habitable room, bathroom, hallway, stairway and at exterior doors.
    • Lighting installed at interior stairways shall have an illuminated wall switch at each floor level separated by 6 or more steps.
    • At least one lighting outlet is required in each unfinished basement space or utility room that is used for storage or contains heating, air-conditioning or other equipment requiring servicing.
    • The light switch shall be located at the point of entry.

    Lighting in clothes closets:

    • The use of incandescent fixtures with open or only partially enclosed lamps and the use of pendant fixtures are prohibited.
    • Fixtures may be located only where there are the following minimum clearances to the nearest point of storage space.
    • Surface mounted incandescent fixtures — 12 minimum.
    • Surface mounted florescent fixtures and recessed fixtures — 6 minimum.

    Electrical panels:

    • Circuit breaker panels shall not be concealed and are not permitted in bathrooms or clothes closets.
    • Lighting is required in the vicinity of the electrical panel.
    • A minimum of 3′ clearance is required in front of existing electrical panels.

    Plumbing Code Requirements

    Show location of any new plumbing fixture such as bar sink(s), bathroom sinks, toilets, bathtubs, showers, hot water heater(s), floor drain(s) and other plumbing fixtures on the floor plans. Show location of plumbing chases. Show the location of new washer hose connection bibs and laundry standpipe in new laundry rooms/space.

    All cleanouts, valves, shut-offs and mechanical joints shall be accessible. Minimum clearance in front of cleanouts shall be 18 inches on 3 inches and larger pipes, and 12 inches on smaller pipes. Concealed cleanouts shall be provided with access of sufficient size to permit removal of the cleanout plug and rodding of the system. Cleanout plugs shall not be concealed with any permanent finishing material. Fixtures having concealed tubular traps shall be provided with an access panel or unobstructed utility space 12 inches in the least dimension.

    Showers: Hinged shower doors shall open outward. All glass which encloses a shower shall be safety glazed. Shower heads shall be water-conserving with a maximum flow rate of 2.5 gallons per minute. All shower control valves shall be anti-scald with a hot water limit of 120F.

    Bathroom sinks: Shall have waste outlets not less than 1 inch in diameter. A strainer, pop-up stopper, crossbar or other device shall be provided to restrict the clear opening of the waste outlet. Faucets shall be water-conserving with a maximum flow rate of 2.2 gallons per minute at 60 psi.

    Toilets: Shall be water-conserving low consumption at 1.6 gallons per flush and shall be provided with a flush tank or similar device designed and installed to supply water in sufficient quantity and flow to flush the contents of the fixture, to cleanse the fixture and refill the fixture trap.

    Bathtubs: Shall have outlets and overflows at least 1 inches in diameter, and the waste outlet shall be equipped with an approved stopper. All bathtub control valves shall be anti-scald with a hot water limit of 120F.

    Sinks: To be provided with waste outlets not less than 1 inches in diameter. A strainer, crossbar or other device shall be provided to restrict the clear opening of the waste outlet. Faucets shall be water-conserving with a maximum flow rate of 2.2 gallons per minute at 60 psi.

    Laundry tubs: Each compartment of a laundry tub shall be provided with a waste outlet not less than 1 inches in diameter and a strainer or crossbar to restrict the clear opening of the waste outlet.

    Clothes washers: The discharge of a clothes washer shall be through an air break.

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