Utah Basement Building Code Checklist

Which codes apply

Utah Code 15A-2-103 adopts the 2021 International Residential Code for houses, the 2023 National Electrical Code, and other codes, each with statewide amendments. For energy, Utah replaced the IRC's energy chapter with its own text effective July 1, 2026.

Bedrooms and egress

• Every sleeping room needs an emergency escape and rescue opening.
• Clear opening at least 24 in. high and 20 in. wide, with the bottom no more than 44 in. above the floor.
• Net clear area: 5 sq ft when the bottom of the opening is within 44 in. above or below the ground outside (a "grade-floor" opening), otherwise 5.7 sq ft.
• Window wells at least 9 sq ft and 36 in. each way, with a permanent ladder or steps when deeper than 44 in.
• Bars, grilles and well covers must open from inside without keys, tools or special knowledge.

Full details: basement egress requirements.

Ceiling height

Habitable rooms

7 ft minimum, including basement portions containing them.

Basement obstructions

Beams, girders and ducts may project down to 6 ft 4 in.

Bathrooms and laundry

6 ft 8 in, and 6 ft 8 in over a 30 by 30 in. area at the showerhead.

Non-habitable basement

6 ft 8 in, or 6 ft 4 in at obstructions.

Smoke and carbon monoxide alarms

When a permitted alteration happens, Utah's amended code requires the dwelling to have smoke alarms located as for new construction. Utah specifically added accessory dwelling units to this trigger. Smoke alarms go:

• in each sleeping room;
• outside each separate sleeping area, near the bedrooms;
• on each additional story, including basements;
• at least 3 ft from a bathroom door with a tub or shower.

Alarms must be interconnected, and listed wireless alarms are allowed. Alarms added because of an alteration may be battery powered. Carbon monoxide alarms are required where there's a fuel-fired appliance or an attached garage, and Utah's amendment places them on each level of the dwelling and outside each separate sleeping area.

Insulation and energy

Utah's replacement energy chapter, effective July 1, 2026, lists for conditioned basements:

Basement walls

R-10 continuous or R-13 cavity

Verification

Inspected before interior finishes are installed

Some city handouts predate this change and list different values. Utah's code also says it doesn't require modifying building components that aren't being altered, so how the table applies to an existing basement is a question for your building department. See basement insulation.

Foam plastic and fireblocking

• Foam insulation must be separated from the interior by an approved thermal barrier, such as 1/2-inch gypsum board.
• Fireblocking is required in concealed spaces of stud walls and furred walls, vertically at ceiling and floor levels and horizontally at intervals no greater than 10 ft, plus at soffits and around pipe and duct openings.

Electrical

• Utah applies the IRC's electrical provisions to houses and the 2023 NEC with amendments.
• Utah deleted NEC 210.12 and the IRC's AFCI location sections, so there's no statewide AFCI requirement for basement rooms.
• GFCI protection applies to unfinished portions of the basement not intended as habitable rooms, along with the usual GFCI locations like bathrooms and near sinks.

Some city checklists still ask plans to label GFCI and arc-fault outlets. Follow your city's submittal requirements.

Radon

Radon-resistant construction is voluntary in Utah. If passive radon controls are installed, they must follow IRC Appendix F. Utah DEQ recommends testing, and retesting the basement level when you start using it. See radon in Utah basements.

City-specific requirements

Cities add their own submittal details: Kaysville's basement checklist lists 14 plan items including ceiling height, furnace clearances and a gas line diagram, Farmington's checklist spells out egress and alarm requirements, and Syracuse's inspection checklist names a four-way, insulation and final inspection. See your city page and the permits guide.

Common questions