Do I need a permit for a small shed in my backyard?

If the shed is under 200 square feet, has no electrical service, and is not in a sensitive area (floodplain, setback zone), many Billings sheds are over-the-counter with a simple application — usually approved same-day. But your footings still need to reach below frost depth (typically 54 inches in Billings). If the shed is 200+ sq ft or has electrical service, it's a full permit with plan review (2–3 weeks). Call the Building Department before you order materials — they'll tell you in 5 minutes whether your specific shed is exempt or needs a full permit.

How deep do deck footings need to be in Billings?

Billings' frost depth varies from 42 to 60 inches depending on microclimate, soil type, and elevation. The building department typically uses 54 inches as the standard for residential deck and post-foundation design. Your frost depth on your specific lot may differ — check with a soils engineer or ask the building department's inspector. They may have a map or local recommendation. If you're in the south-side clay zone, frost heave and soil movement are compounded, and the inspector will be stricter about footing design. Don't guess — ask.

Can I pull permits myself as an owner-builder in Billings?

Yes, for owner-occupied residential work. You can pull building, mechanical, plumbing, and structural permits. You cannot pull electrical permits — Montana law requires a licensed electrician to file electrical work, even if you're doing it yourself. If you're hiring contractors for parts of the job, the contractor's license holders will pull their own permits. Owner-builders pay the same permit fees and are held to the same code as contractors; there are no discounts or exemptions.

What happens if I build without a permit in Billings?

If the Building Department finds unpermitted work, they can issue a stop-work order and require you to demolish, bring the work into compliance, or pay fines. If you sell the house, the new owner's lender and title company will likely discover unpermitted work during due diligence — and you may be forced to pay for after-the-fact inspections, code corrections, or even removal. Unpermitted structural work (decks, additions, roof framing) is especially risky; insurance may deny claims if work was not permitted. The permit fee is cheap compared to the cost of fixing an unpermitted problem later.

How long does it take to get a permit in Billings?

Over-the-counter permits (fence, small shed, simple alterations) are issued same-day if you show up before 3 PM with a complete application. Full-review permits (additions, basement finishing, major electrical or structural work) take 2–3 weeks for plan review and typically one more week for final inspection scheduling. Total timeline from application to first inspection is usually 3–4 weeks, longer if the building department asks for revisions or if you're in a soil-investigation zone. Submit a complete application with all required drawings and calculations the first time — incomplete applications get rejected and reset the clock.

Do I need a soils investigation for my project in Billings?

If your lot is in an expansive-clay zone (south and central Billings are most at risk), and you're doing foundation, footing, or deck work, you may need a geotechnical investigation. The building department has a soil-hazard map; check your address. If you're in a clay zone, the inspector will likely require a soils report before approving foundation design or an extensive deck system. Cost is typically $300–$800. If you're on the north side or in a newer subdivision with sandy glacial soils, you probably won't need one — but don't assume. Ask the Building Department or your engineer.

What is the design snow load for roofs in Billings?

Billings uses approximately 25 psf ground snow load and 20 psf roof snow load. This is a moderate load — not as severe as mountain zones, but higher than southern plains. Roof trusses and connections are standard residential design for these loads. If you're replacing a roof with a material change (asphalt to metal, or significant structural changes), the building department may require a structural engineer's stamp confirming the roof can handle the design load. Like-for-like reroof of existing asphalt shingles usually doesn't require structural calculations.

Is radon a concern for new construction in Billings?

Billings is in EPA Zone 2, meaning radon potential is moderate to high depending on neighborhood and soil. Montana does not mandate radon testing or mitigation for new construction, but radon-resistant construction (passive radon system, vented soil depressurization) is a smart investment. If you're finishing a basement, the building department may recommend radon control. Test your home after occupancy — a $150–$300 radon test can tell you if active mitigation is needed. Don't leave this to chance if you have kids or plan to stay long-term.

Can I do electrical work myself in Billings?

No. Montana law requires a licensed electrician to file and oversee all electrical permits, even if you are an owner-builder. You cannot pull an electrical permit yourself, and you cannot do electrical work without a licensed electrician's involvement. If you hire an electrician, they pull the permit; if you want to do the work yourself, you must hire a licensed electrician to pull the permit and oversee the job. This is a state law, not a Billings local rule. Electrical work found to be unpermitted and unlicensed can result in fines, insurance denial, and forced correction.

What do I need to submit with a residential addition permit application?

You'll need site plan showing property lines and setbacks, floor plans and elevations of the addition, electrical layout, foundation/footing design, roof framing plan, and structural calculations if required. The building department also wants to see how the addition ties into existing utilities (water, sewer, electric, HVAC). If your lot is in an expansive-clay zone, include a soils investigation or engineering report. Submit everything at once — incomplete applications get rejected and add weeks to the review cycle. The Building Department can provide a full checklist; call and ask or check the online portal.

Building Permits in Billings, MT (2026)

Do I need a permit in Billings, Montana?

Billings sits in IECC Climate Zone 6B — cold, dry winters with a frost depth between 42 and 60 inches depending on your specific lot. That frost depth is the first thing the building department cares about for any project involving foundations, footings, or ground anchors. The City of Billings Building Department enforces the 2015 International Building Code with Montana state amendments, and they process permits at a steady pace — plan review takes 2–3 weeks for most residential projects, faster for over-the-counter items like fence permits and water-heater swaps.

Billings is also owner-builder friendly for owner-occupied residential projects. You can pull permits yourself if you're the homeowner doing the work, or you can hire a contractor. Either way, you're accountable to the same code: the same frost-depth requirements, the same electrical standards, the same roof-load calculations that account for Billings' moderate snow load (around 25 psf design load). What changes is paperwork — owner-builders file the same applications as contractors, but you don't need a contractor's license.

The tricky part for Billings isn't the building code itself — it's the soil. Yellowstone County's glacial soils are loaded with expansive clay in many neighborhoods. That means a standard deck footing or a basement foundation might need a geotechnical report or special design if you're in the wrong part of town. The building department won't let you guess. Bring a soils investigation if your lot sits on clay, or be ready to hire one.

Start by checking which projects you're planning — the list below covers the most common Billings permits. Then call the City of Billings Building Department or visit their online portal to confirm your specific project's requirements. Five minutes on the phone now saves five weeks of back-and-forth later.

What's specific to Billings permits

Billings' 42–60 inch frost depth is deeper than the IRC's blanket 36-inch requirement. This matters for every project that digs into the ground: deck posts, shed foundations, fence posts, garage slabs, basement footings. A deck post that would be legal in Texas at 36 inches is not legal in Billings — your footings need to bottom out below frost depth, typically 54 inches in most of Billings proper. The building department will call this out in plan review if your drawings show anything shallower. Some inspectors are stricter than others, but frost heave is not negotiable — a post that shifts 2–3 inches when the ground freezes will crack a deck rim and destroy attached structures.

Expansive clay is the second local wild card. Parts of Billings' south side and central neighborhoods sit on Tertiary clay deposits that swell when wet and shrink when dry. If you're building on a slope or in a newly developed area, the city may require a soils report before they'll approve a foundation, deck footing system, or even a large patio. This is not petty bureaucracy — clay movement has cracked plenty of Billings basements and shifted patios. The building department publishes a soil-hazard map; check your address on it. If you're in a clay zone, budget $300–$800 for a geotechnical investigation before you design anything. It's cheaper than redesigning after the city rejects your plans.

Billings uses the 2015 International Building Code with Montana state amendments. The main Montana-specific tweak for residential work is stricter R-value requirements for attic insulation (R-49 in Billings, versus the ICC's R-38). Radon testing is not mandatory for new construction in Montana, but it's recommended — Billings sits in EPA Zone 2 radon area, meaning some homes will have elevated levels. Check your radon potential before you finish a basement. The state also enforces the 2015 International Energy Code, which means windows, doors, and insulation must hit specific U-factors and R-values depending on your climate zone.

The City of Billings offers an online permit portal, but it's not a full-service system like some larger cities. You can file some permits online (fence, shed, residential additions) and track them, but you'll likely need to submit plan sets and pay in person or by check. The building department does not process credit-card payments online, so bring a check or be ready to pay at the counter. Over-the-counter permits (fence, some alterations) can be issued same-day if you show up before 3 PM and your application is complete. Don't assume — call ahead and confirm which permits they'll issue over the counter in your category.

Billings has moderate snow load (about 25 psf ground snow load, 20 psf roof load). Roof trusses and structure-to-deck connections are standard — there's no special snow-load allowance that changes residential work. But if you're adding a deck or expanding a roof area, the structural engineer or designer needs to spec for that load. The building department will ask for roof-load calculations in the plan set if you're doing a major roof or truss replacement. Owner-builders often skip this and get rejected; don't.

Most common Billings permit projects

These projects appear in the Building Department's queue every week. Each one has a different threshold, timeline, and fee. Click through to the project-specific page to get the yes/no, the filing checklist, and what to expect in plan review.

Do I need a building permit
in Billings, MT?

Do I need a permit in Billings, Montana?

What's specific to Billings permits

Most common Billings permit projects

Decks

Fences

Roof replacement

Electrical work

Room additions

Do I need a building permit in Billings, MT?

Do I need a permit in Billings, Montana?

What's specific to Billings permits

Most common Billings permit projects

Decks

Fences

Roof replacement

Electrical work

Room additions

Do I need a building permit
in Billings, MT?