Do I need a permit to build a deck in Billings, MT?

Yes. In Billings, any deck attached to the home requires a building permit, and so does any freestanding deck that is more than 30 inches above finished grade. You will need to submit a site plan showing the deck's dimensions, its distance from all property lines, and its relationship to the existing house footprint. The site plan must be drawn to scale and include a north arrow. Permit fees are based on the estimated construction value of the project. The City of Billings Building Services Division reviews residential deck permits, and standard plan review typically takes 10 to 15 business days for a complete application. Work started before a permit is issued can result in stop-work orders and additional fees.

How much does a building permit and site plan cost in Billings?

Permit fees in Billings are calculated based on the estimated fair-market construction value of your project. For a simple residential project such as a small shed or fence, the plan review and permit fee may be as low as $75 to $150. For a deck, the fee commonly falls in the $150 to $400 range. Larger projects such as room additions or ADUs can carry fees of several hundred to over a thousand dollars depending on valuation. Site plan preparation is a separate cost: if you hire a drafter or use an online tool like Site Plan Creator, costs can range from free to a few hundred dollars. Licensed architects or surveyors will charge more. Always confirm current fee schedules directly with the City of Billings Building Services Division, as fees are updated periodically.

How long does it take to get a building permit approved in Billings, MT?

For standard residential projects with a complete application, the City of Billings Building Services Division typically completes plan review in 10 to 15 business days. That means roughly two to three calendar weeks from submission to permit issuance, assuming no correction comments are issued. If the reviewer identifies deficiencies in your site plan or construction drawings, you will receive a correction letter and the clock resets once you resubmit. Projects in FEMA floodplain zones, historic overlay districts, or those requiring a zoning variance can take considerably longer, sometimes six to eight weeks or more. Submitting a complete, accurate site plan the first time is the single best way to minimize delays.

What does Billings require on a residential site plan?

A residential site plan submitted to the City of Billings should include: the lot boundaries with dimensions, a north arrow, a graphic scale bar, the location and footprint of all existing structures on the property, the location and dimensions of the proposed structure, setback distances from all property lines, driveways and access points, utility and drainage easements (taken from your plat), and any relevant topographic features such as slopes or watercourses. For floodplain properties, the base flood elevation and finished floor elevation must also be noted. The plan does not need to be prepared by a licensed surveyor for most residential projects, but it must be drawn to scale and be legible. Inaccurate or incomplete site plans are the leading cause of permit application rejections in Billings.

Can I draw my own site plan in Billings, or do I need a licensed surveyor?

For most standard residential permits in Billings, such as decks, sheds, pools, and smaller additions, you are not required to hire a licensed surveyor or engineer to prepare your site plan. Homeowners and contractors can draw their own site plans, provided the plan is accurate, to scale, and includes all required elements. Tools like Site Plan Creator allow you to produce a professional-quality, to-scale site plan without CAD software. However, if your project involves a new home, a large addition, a structure near the property line, or a property in a floodplain or hillside area, the city may require stamped drawings from a licensed Montana architect or engineer. Always confirm requirements with the Building Services Division before you start.

What are the setback requirements for residential properties in Billings?

Setback requirements in Billings vary by zoning district. In typical single-family residential zones (R-1), the front yard setback is generally 20 to 25 feet from the front property line. Side yard setbacks are typically 5 to 7 feet for interior lots, while corner lots often require a 10- to 15-foot setback from the street-side property line. Rear yard setbacks for principal structures are usually 20 to 25 feet. Detached accessory structures such as garages and sheds may be placed closer to the rear and side property lines, sometimes as close as 3 to 5 feet depending on the zone. These are general ranges: your specific parcel may have different requirements based on its zoning designation, overlay district, or recorded plat. Always verify with the City of Billings Planning and Community Services Department before finalizing your plans.

Where do I submit my site plan and permit application in Billings?

The City of Billings accepts residential permit applications both online and in person. Online submissions are made through the city's Citizen Self-Service portal, accessible from the Building Services Division page on the City of Billings website (billingsmt.gov). You will need to create an account, upload your site plan and supporting documents, and pay the plan review fee electronically. In-person submissions can be made at City Hall, located at 210 N 27th St, Billings, MT 59101. The Building Services Division counter is open during regular business hours. Online submission is generally faster and allows you to track your application status in real time. For questions before submitting, you can reach Building Services at (406) 657-8261.

What happens if I build without a permit in Billings, MT?

Building without a required permit in Billings can have serious consequences. If a code enforcement officer or neighbor complaint triggers an inspection, the city may issue a stop-work order requiring all construction to halt immediately. You may be required to obtain an after-the-fact permit, which typically costs double the standard permit fee. In some cases, the city can require you to remove or demolish unpermitted work if it cannot be brought into compliance. Unpermitted structures can also create problems when you sell your home, as title companies and buyers' lenders often require permit documentation. Additionally, your homeowner's insurance may deny claims related to unpermitted construction. The safest and most cost-effective approach is always to pull the permit before work begins.

Does my Billings property fall in a FEMA floodplain, and how does that affect my permit?

Portions of Billings along the Yellowstone River, Alkali Creek, and other drainageways fall within FEMA-designated Special Flood Hazard Areas (SFHAs), shown on Flood Insurance Rate Maps (FIRMs). If your property is in an SFHA, any development, including additions, accessory structures, and grading, requires a separate floodplain development permit from the City of Billings in addition to the standard building permit. Your site plan must show the base flood elevation, and finished floor elevations for new or substantially improved structures must meet or exceed that level. An elevation certificate prepared by a licensed surveyor is typically required. You can check your property's flood zone status using the FEMA Flood Map Service Center at msc.fema.gov. Floodplain requirements add time and cost to a project, so identify your flood zone status early in the planning process.

What are the rules for building an ADU in Billings, MT?

Billings has broadened its ADU allowances in recent years, permitting accessory dwelling units in most single-family and two-family residential zones. Both attached ADUs (such as a basement apartment) and detached ADUs (such as a backyard cottage) are permitted, subject to specific requirements. The ADU generally cannot exceed 50% of the primary dwelling's floor area or a maximum square footage set by the zone. The lot must meet minimum size thresholds, and the ADU must comply with setback rules, which may be reduced for detached units in rear yards. Utility connections, parking, and in some zones owner-occupancy requirements also apply. A full building permit and site plan are required. Billings Planning and Community Services can provide a pre-application meeting to walk through ADU requirements for your specific parcel before you invest in drawings.

Site Plan Requirements in Billings, MT (Permit Guide)

By Site Plan Creator Team • May 30, 2026

Billings, Montana homeowners need a compliant site plan for most residential building permits, from decks and sheds to ADUs and additions. This guide covers Billings-specific permit triggers, setback rules, zoning quirks, and how to submit your application to the City of Billings Building Services Division.

Site plan requirements for residential properties in Billings, Montana

Residential Site Plans and Building Permits in Billings, MT

Billings is Montana's largest city, a fast-growing hub on the Yellowstone River where new construction, backyard upgrades, and accessory dwelling units are reshaping neighborhoods from the South Side to the Heights. Whether you're adding a deck to your rimrock-view home, converting a garage into a rental unit, or installing a pool in the Westpark area, the City of Billings requires a building permit and, in most cases, a site plan before any work begins. Understanding what the city expects can save you weeks of back-and-forth with the Building Services Division and keep your project on schedule.

What Is a Residential Site Plan and Why Does Billings Require One?

A residential site plan is a scaled, bird's-eye drawing of your property showing the lot boundaries, existing structures, proposed construction, setbacks from property lines, driveways, utilities, and drainage features. Billings uses site plans to verify that proposed work complies with the city's zoning ordinance, the 2021 International Building Code (IBC) and International Residential Code (IRC) as adopted by Montana, and any applicable overlay district rules.

The city's plan reviewers check your site plan to confirm:

The proposed structure respects required setbacks from all property lines
Lot coverage limits are not exceeded
Access, drainage, and utility easements are not encroached upon
The project is consistent with the zoning district designation for your parcel

Without a compliant site plan, your permit application will be returned incomplete, delaying your project start date.

Which Residential Projects Require a Permit in Billings?

The City of Billings Building Services Division administers residential permits. Most structural or land-disturbing improvements require a permit. Common residential permit triggers include:

Decks and Patios

Any deck attached to the home, or a freestanding deck more than 30 inches above grade, requires a building permit and a site plan showing setbacks and dimensions.

Sheds and Accessory Structures

Detached sheds or garages over 200 square feet require a permit. Smaller sheds may be exempt from the building permit but must still comply with setback rules. When in doubt, confirm with Building Services before you build.

Swimming Pools and Hot Tubs

Above-ground and in-ground pools with a water depth exceeding 24 inches require a permit. Barrier and fencing requirements under the IRC apply, and your site plan must show pool placement relative to property lines and the home.

Fences

Fences in Billings generally do not require a building permit, but they must comply with height limits by zone (typically 4 feet in front yards, 6 feet in side and rear yards) and cannot be placed within certain easements. Always check your plat for utility easements before installing.

Room Additions and Garage Conversions

Any addition to the home's footprint or interior conversion that changes the use of a space (such as converting a garage to living area) requires a full building permit with architectural drawings and a site plan.

Accessory Dwelling Units (ADUs)

Billings has expanded its allowance for ADUs in recent years, permitting them in most residential zones. A detached ADU requires a building permit, a site plan, and must meet minimum lot size, setback, and utility connection requirements. ADUs cannot exceed the square footage limits set by the zone or 50% of the primary dwelling's floor area, whichever is less in most cases.

Driveways

New driveways or driveway expansions that connect to a public street require a Right-of-Way permit from the Public Works Department in addition to any applicable building review. Your site plan should show the driveway width, apron location, and proximity to lot lines.

Zoning and Local Considerations in Billings

Billings is divided into several zoning districts, including R-1 (Single-Family Residential), R-2 (Two-Family), R-3 (Multiple-Family), and various mixed-use and commercial zones. The city's zoning map is administered through the Planning and Community Services Department.

A few locally important considerations:

Rimrock and hillside areas: Properties near the rimrock escarpment may face additional geotechnical review requirements due to slope stability concerns. If your lot is near the rim, expect the city to request a soils report or engineer's letter.
Floodplain properties: Portions of Billings along the Yellowstone River and its tributaries fall within FEMA-designated Special Flood Hazard Areas (SFHAs). Projects in these zones require a floodplain development permit and must comply with FEMA floodplain management standards. Finished floor elevations must be documented.
Historic districts: Billings has a designated historic preservation overlay in portions of the downtown and surrounding neighborhoods. Exterior alterations in these areas may require a Certificate of Appropriateness from the Historic Preservation Officer before a building permit is issued.
HOA restrictions: Many Billings subdivisions, particularly in the West End and Heights, have active homeowners associations with additional design standards. HOA approval does not replace city permits, and city permits do not override HOA rules. Check both before you build.

Typical Setback Requirements in Billings

Setbacks vary by zoning district. The following are general ranges for standard residential zones in Billings:

Front yard setback: 20 to 25 feet from the front property line (varies by district and street classification)
Side yard setback: 5 to 7 feet for interior lots; corner lots may have a 10- to 15-foot street-side setback
Rear yard setback: 20 to 25 feet for principal structures; accessory structures may be placed closer, typically 5 feet from the rear property line
Garage setbacks: Detached garages and ADUs often have reduced setback allowances (as little as 3 to 5 feet from the rear and side in some zones)

Always verify your parcel's specific setbacks using the Montana Code Annotated and the City of Billings zoning ordinance before finalizing your site plan dimensions.

How to Submit a Permit Application in Billings

Billings has moved toward online permit submission through its Citizen Self-Service portal, though in-person submissions at City Hall are still accepted.

Gather your documents. Prepare your site plan, construction drawings, property survey (if available), and any specialty reports (soils, floodplain elevation certificate).
Create an account on the city's online portal. Visit the Building Services Division page on the City of Billings website and access the permit portal to submit applications electronically.
Submit your application and pay the plan review fee. Fees are based on the estimated construction value. Residential plan review fees in Billings typically range from around $100 for simple projects to several hundred dollars for larger additions or ADUs.
Wait for plan review. Standard residential plan review in Billings typically takes 10 to 15 business days for complete applications. Complex projects, those in floodplain zones, or applications requiring zoning variance review may take longer.
Respond to correction comments. If the reviewer identifies deficiencies, you will receive a correction letter. Revise your site plan and resubmit promptly to avoid losing your place in the queue.
Receive your permit and schedule inspections. Once approved, post your permit on site, begin work, and call for required inspections at each phase (foundation, framing, final).

Common Reasons Billings Permit Applications Are Rejected

Plan reviewers in Billings frequently flag these issues:

Site plan is not drawn to scale or lacks a north arrow and scale bar
Setback dimensions are missing or do not match the zoning district requirements
Proposed structure encroaches on a platted utility or drainage easement
Lot coverage calculation is not included or exceeds the maximum for the zone
Floodplain elevation certificate is missing for properties in an SFHA
Construction drawings lack sufficient detail (missing dimensions, materials, or structural notes)
ADU application does not address utility metering or owner-occupancy requirements

Avoiding these mistakes starts with a clean, complete site plan that clearly communicates your project to the reviewer.

Create Your Billings Site Plan with Site Plan Creator

Site Plan Creator makes it straightforward for Billings homeowners and contractors to produce professional, to-scale site plans that meet city requirements. You don't need CAD software or a surveying background. Simply enter your property dimensions, place structures, add setback lines, and export a print-ready PDF ready for submission to the City of Billings Building Services Division. Start your site plan today at siteplancreator.com and move your permit application forward with confidence.

Frequently Asked Questions

Do I need a permit to build a deck in Billings, MT?: Yes. In Billings, any deck attached to the home requires a building permit, and so does any freestanding deck that is more than 30 inches above finished grade. You will need to submit a site plan showing the deck's dimensions, its distance from all property lines, and its relationship to the existing house footprint. The site plan must be drawn to scale and include a north arrow. Permit fees are based on the estimated construction value of the project. The City of Billings Building Services Division reviews residential deck permits, and standard plan review typically takes 10 to 15 business days for a complete application. Work started before a permit is issued can result in stop-work orders and additional fees.
How much does a building permit and site plan cost in Billings?: Permit fees in Billings are calculated based on the estimated fair-market construction value of your project. For a simple residential project such as a small shed or fence, the plan review and permit fee may be as low as $75 to $150. For a deck, the fee commonly falls in the $150 to $400 range. Larger projects such as room additions or ADUs can carry fees of several hundred to over a thousand dollars depending on valuation. Site plan preparation is a separate cost: if you hire a drafter or use an online tool like Site Plan Creator, costs can range from free to a few hundred dollars. Licensed architects or surveyors will charge more. Always confirm current fee schedules directly with the City of Billings Building Services Division, as fees are updated periodically.
How long does it take to get a building permit approved in Billings, MT?: For standard residential projects with a complete application, the City of Billings Building Services Division typically completes plan review in 10 to 15 business days. That means roughly two to three calendar weeks from submission to permit issuance, assuming no correction comments are issued. If the reviewer identifies deficiencies in your site plan or construction drawings, you will receive a correction letter and the clock resets once you resubmit. Projects in FEMA floodplain zones, historic overlay districts, or those requiring a zoning variance can take considerably longer, sometimes six to eight weeks or more. Submitting a complete, accurate site plan the first time is the single best way to minimize delays.
What does Billings require on a residential site plan?: A residential site plan submitted to the City of Billings should include: the lot boundaries with dimensions, a north arrow, a graphic scale bar, the location and footprint of all existing structures on the property, the location and dimensions of the proposed structure, setback distances from all property lines, driveways and access points, utility and drainage easements (taken from your plat), and any relevant topographic features such as slopes or watercourses. For floodplain properties, the base flood elevation and finished floor elevation must also be noted. The plan does not need to be prepared by a licensed surveyor for most residential projects, but it must be drawn to scale and be legible. Inaccurate or incomplete site plans are the leading cause of permit application rejections in Billings.
Can I draw my own site plan in Billings, or do I need a licensed surveyor?: For most standard residential permits in Billings, such as decks, sheds, pools, and smaller additions, you are not required to hire a licensed surveyor or engineer to prepare your site plan. Homeowners and contractors can draw their own site plans, provided the plan is accurate, to scale, and includes all required elements. Tools like Site Plan Creator allow you to produce a professional-quality, to-scale site plan without CAD software. However, if your project involves a new home, a large addition, a structure near the property line, or a property in a floodplain or hillside area, the city may require stamped drawings from a licensed Montana architect or engineer. Always confirm requirements with the Building Services Division before you start.
What are the setback requirements for residential properties in Billings?: Setback requirements in Billings vary by zoning district. In typical single-family residential zones (R-1), the front yard setback is generally 20 to 25 feet from the front property line. Side yard setbacks are typically 5 to 7 feet for interior lots, while corner lots often require a 10- to 15-foot setback from the street-side property line. Rear yard setbacks for principal structures are usually 20 to 25 feet. Detached accessory structures such as garages and sheds may be placed closer to the rear and side property lines, sometimes as close as 3 to 5 feet depending on the zone. These are general ranges: your specific parcel may have different requirements based on its zoning designation, overlay district, or recorded plat. Always verify with the City of Billings Planning and Community Services Department before finalizing your plans.
Where do I submit my site plan and permit application in Billings?: The City of Billings accepts residential permit applications both online and in person. Online submissions are made through the city's Citizen Self-Service portal, accessible from the Building Services Division page on the City of Billings website (billingsmt.gov). You will need to create an account, upload your site plan and supporting documents, and pay the plan review fee electronically. In-person submissions can be made at City Hall, located at 210 N 27th St, Billings, MT 59101. The Building Services Division counter is open during regular business hours. Online submission is generally faster and allows you to track your application status in real time. For questions before submitting, you can reach Building Services at (406) 657-8261.
What happens if I build without a permit in Billings, MT?: Building without a required permit in Billings can have serious consequences. If a code enforcement officer or neighbor complaint triggers an inspection, the city may issue a stop-work order requiring all construction to halt immediately. You may be required to obtain an after-the-fact permit, which typically costs double the standard permit fee. In some cases, the city can require you to remove or demolish unpermitted work if it cannot be brought into compliance. Unpermitted structures can also create problems when you sell your home, as title companies and buyers' lenders often require permit documentation. Additionally, your homeowner's insurance may deny claims related to unpermitted construction. The safest and most cost-effective approach is always to pull the permit before work begins.
Does my Billings property fall in a FEMA floodplain, and how does that affect my permit?: Portions of Billings along the Yellowstone River, Alkali Creek, and other drainageways fall within FEMA-designated Special Flood Hazard Areas (SFHAs), shown on Flood Insurance Rate Maps (FIRMs). If your property is in an SFHA, any development, including additions, accessory structures, and grading, requires a separate floodplain development permit from the City of Billings in addition to the standard building permit. Your site plan must show the base flood elevation, and finished floor elevations for new or substantially improved structures must meet or exceed that level. An elevation certificate prepared by a licensed surveyor is typically required. You can check your property's flood zone status using the FEMA Flood Map Service Center at msc.fema.gov. Floodplain requirements add time and cost to a project, so identify your flood zone status early in the planning process.
What are the rules for building an ADU in Billings, MT?: Billings has broadened its ADU allowances in recent years, permitting accessory dwelling units in most single-family and two-family residential zones. Both attached ADUs (such as a basement apartment) and detached ADUs (such as a backyard cottage) are permitted, subject to specific requirements. The ADU generally cannot exceed 50% of the primary dwelling's floor area or a maximum square footage set by the zone. The lot must meet minimum size thresholds, and the ADU must comply with setback rules, which may be reduced for detached units in rear yards. Utility connections, parking, and in some zones owner-occupancy requirements also apply. A full building permit and site plan are required. Billings Planning and Community Services can provide a pre-application meeting to walk through ADU requirements for your specific parcel before you invest in drawings.

How to Create a Site Plan in Billings

Confirm Your Permit Requirements: Before drawing anything, contact the City of Billings Building Services Division or check the city's website to confirm whether your specific project requires a building permit and site plan. Describe your project type, size, and location. If your property is near the rimrock, in a FEMA floodplain, or within a historic overlay district, identify those conditions early, as they add review steps and documentation requirements that affect your timeline and budget.
Gather Your Property Information: Collect your property survey, plat map, and any existing as-built drawings for your home. Your plat map, available from Yellowstone County or the City of Billings, shows lot dimensions, easements, and right-of-way lines that must appear on your site plan. Measure existing structures on your property so their footprints can be accurately represented. Note any utility easements that could restrict where you place the proposed structure.
Create a To-Scale Site Plan: Use Site Plan Creator or similar software to draw your site plan to scale. Include lot boundaries with dimensions, a north arrow, a scale bar, all existing structures, the proposed structure with dimensions, setback distances from all property lines, driveways, and any easements. For floodplain properties, add base flood elevation notes. Make sure all text is legible when printed at the plan sheet size you intend to submit. A complete, accurate site plan is the single most important factor in getting your Billings permit approved on the first review.
Submit Your Application Online or In Person: Log in to the City of Billings Citizen Self-Service portal to submit your permit application electronically, or bring printed documents to Building Services at City Hall, 210 N 27th St. Upload or provide your site plan, construction drawings, and any required supplemental documents such as an elevation certificate. Pay the plan review fee at time of submission. Online submission allows you to track review status and receive correction comments digitally, which speeds up the process.
Respond to Reviewer Comments and Get Approved: If the plan reviewer identifies deficiencies, you will receive a correction letter, typically within 10 to 15 business days of submission. Review each comment carefully, revise your site plan or drawings accordingly, and resubmit through the same portal or in person. Once all corrections are resolved, the city will issue your permit. Post the permit card visibly on your job site before starting construction and schedule required inspections at each phase of the project.