Yellowstone County, MT Building Setbacks & Zoning: Lot Coverage Limits (2026)
Key Facts
- N4 residential cap
- 30% max building coverage
- Agricultural district cap
- 15% max lot coverage
- I1/I2 industrial cap
- 75% max lot coverage
- Administrative relief
- Up to 10% increase, select districts
- Beyond that
- Variance required under § 27-1626
- Penalty
- Misdemeanor, fine or up to 6 months jail
Summary
Unincorporated Yellowstone County caps how much of a lot a building can cover, and the limit changes by zoning district: 30% in the N4 large-lot residential district, 15% in the Agricultural district, and up to 75% in the I1 and I2 industrial districts. The Yellowstone County Zoning Code sets each cap in its own district's site and structure table.
The following site and structure regulations apply to any lot in the N4 district. Refer to 27-303 for general regulations applicable to all districts and Table 27-300-3, below, for regulations specific to this district, keyed to illustrations in Figure 27-300(2). See Article 27-1800 for definitions and information on how to measure the following regulations. TABLE 27-300-3. SITE AND STRUCTURE REGULATIONS ... 7&9 Maximum Total Building Coverage (%) 30
Full Breakdown
Section 27-304 governs the N4, Large Lot Suburban Neighborhood Residential district, and its Table 27-300-3 sets Maximum Total Building Coverage at 30 percent, alongside a 20-foot minimum front setback, 5-foot side setback, and 34-foot maximum height. 1, adopted under Section 27-903, caps Lot Coverage at 15 percent on a minimum 10-acre lot, well below the residential figure because agricultural parcels carry larger required setbacks (35 feet front, side-adjacent-to-street, and rear). 2 under Section 27-602 allow both the I1 Light Industrial and I2 Heavy Industrial districts to cover up to 75 percent of the lot.
Every district table in Article 27-300 and Article 27-900 works the same way: the coverage percentage is a maximum, not a target, and it is measured together with the district's minimum lot size, setbacks, and height limit rather than in isolation. A property that needs to exceed its district's cap has two paths: Section 27-1614, Administrative Relief, lets the zoning coordinator approve up to a 10 percent increase in lot coverage for the A, RMH, RRMH, C3, CX, I1, I2, and P1-3 districts, while a larger increase, or an increase in a district Section 27-1614 does not cover, requires a variance under Section 27-1626 reviewed by the review authority. C.
Violations & Fines
Building beyond a district's maximum lot coverage is a zoning violation under Section 27-1702.C (making lot area or setbacks nonconforming) and Section 27-1702.A. Section 27-1704.G classifies the violation as a misdemeanor: a fine up to the state statutory limit, up to six months in the county jail, or both, plus all costs and expenses, with each day the excess coverage remains counted as a separate offense.
Frequently Asked Questions
What is the maximum lot coverage for a house in unincorporated Yellowstone County?
Can a property get more lot coverage than its district allows?
How does the Agricultural district's lot coverage compare to residential?
What happens when a building exceeds its lot's coverage limit?
Sources & Official References
Other rules in Yellowstone County
Compare Yellowstone County to another location·View the Montana building setbacks & zoning overview
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