Boise, ID Zoning
Districts & Requirements

Every zoning district in Boise with permitted uses, setbacks, height limits, and density requirements — in plain English. Boise adopted a Modern Zoning Code effective late 2023 — the first rewrite since 1966. Districts use an R/MX/I framework: R-1A through R-3 for residential, MX-1 through MX-5 for mixed-use, I-1 through I-3 for industrial. No maximum density in any MX district. Mixed-use zones have 0-ft minimum setbacks and build-to-max requirements to create urban street walls.

15

Zoning districts

8

Overlay districts

250,000

Population

2024

Code adopted

Quick Reference

Find your district, see what you can do. Click any row for details.

DistrictAt a glanceHeightCoverage
R-1AEstate lots, 20K SF minimum, 2.1 units/acre cap. Single-family only. No subdivision potential.35 ftNot specified
R-1BSuburban single-family, 9,000 SF lots, 4.8 units/acre. Standard Boise subdivision product.35 ftNot specified
R-1CTraditional neighborhood, 3,500 SF lots, 12.4 units/acre. Duplexes with CUP. 3 stories / 40 ft.3 stories / 40 ftNot specified
R-2Missing middle by right: duplex, triplex, fourplex, townhouse, apartment. 4 stories / 45 ft. No max density.4 stories / 45 ftNot specified
R-3Urban multifamily, 4 stories / 50 ft. Attached units at 1,500 SF lots. Highest-density residential zone.4 stories / 50 ftNot specified
MX-1Neighborhood-scale mixed-use, 45 ft. No lot minimums, 0-ft front setback. Small-scale retail + residential.45 ftNot specified
MX-2General mixed-use, 45 ft. Community-scale commercial + residential. No density cap.45 ftNot specified
MX-3Active mixed-use, 70 ft. 4-story minimum on large sites. 60% active ground floor required.70 ftNot specified
MX-4Transit-oriented development, 70 ft. 4-story minimum. Highest-intensity corridor district.70 ftNot specified
MX-5No height limit, no density cap, 0-ft setbacks on all sides. Boise's most valuable zoning. 80% active ground floor.No limitNot specified
MX-UBoise State area. Unlimited height with conditions. Student housing, campus commercial, institutional.70 ft (up to unlimited with conditions)Not specified
MX-HHealthcare campus district, 78 ft. Medical office, hospital, senior housing. Scaled setbacks by height.78 ftNot specified
I-1Light manufacturing, flex, warehouse. 55 ft, 0-ft side/rear setbacks. No lot minimums.55 ftNot specified
I-2Heavy industrial. 55 ft, 30-ft frontage minimum. Hazardous uses need CUP.55 ftNot specified
I-3Tech campus, 150 ft max. Massive setbacks scale with height. Data centers, advanced manufacturing.150 ftNot specified

Residential

5 districts in Boise

R-1A

Residential Large Lot

Large-lot single-family on half-acre parcels. Density capped at 2.1 units/acre — no path to multifamily without a rezone. If you're looking at R-1A land, you're building custom homes.

What you can build

  • Single-family detached
  • One ADU (up to 900 SF)
  • Home occupation
  • Duplex (conditional use permit)
  • Townhouses, triplexes, or apartments
  • Commercial or retail
  • Subdivision below 20,000 SF lots

Key numbers

Height
35 ft
Lot min
20,000 SF (~0.46 acres)
Width
75 ft avg
Coverage
Not specified
Front
20 ft (garage/entry), 15 ft (remainder)
Side
10 ft interior, 20 ft street side
Rear
20 ft

What this means in practice

At 2.1 units/acre, a 1-acre R-1A parcel yields exactly 2 lots. The 20,000 SF minimum and 75-ft width mean you're building on half-acre pads — custom home territory. ADUs are allowed up to 900 SF with no additional parking required. If you have a large R-1A parcel near an R-1C or R-2 boundary, the rezone play is worth exploring.

R-1B

Residential Suburban

The standard Boise suburban residential district. 9,000 SF lots, 50-ft wide — bread-and-butter spec home territory. Duplex allowed with CUP.

What you can build

  • Single-family detached
  • One ADU (up to 900 SF)
  • Duplex (conditional use permit)
  • Home occupation
  • Townhouses or multifamily
  • Triplex, fourplex, or apartments
  • Commercial or retail

Key numbers

Height
35 ft
Lot min
9,000 SF
Width
50 ft avg
Coverage
Not specified
Front
20 ft (garage/entry), 15 ft (remainder)
Side
10 ft interior, 20 ft street side
Rear
20 ft

What this means in practice

4.8 units/acre on a 1-acre parcel = 4 lots at 9,000 SF each. At 35 ft height, you're building 2-story homes up to ~3,500 SF. This is Boise's largest residential zone by acreage — lenders and appraisers know it well. ADU potential adds rental income on every lot.

R-1C

Residential Traditional

Traditional neighborhood infill at 3,500 SF minimum lots. 50% more density than pre-2023 code. Three stories allowed. Duplexes via CUP, ADUs by right.

What you can build

  • Single-family detached
  • One ADU (up to 900 SF)
  • Duplex (conditional use permit)
  • Manufactured home
  • Corner-lot neighborhood cafe or retail (up to 2,000 SF)
  • Townhouses or multifamily by right
  • Standalone commercial (except corner lots)
  • Triplex or fourplex (need R-2)

Key numbers

Height
3 stories / 40 ft
Lot min
3,500 SF
Width
25 ft avg
Coverage
Not specified
Front
20 ft (garage/entry), 15 ft (remainder)
Side
5 ft or 10 ft interior, 15-20 ft street side
Rear
15 ft

What this means in practice

12.4 units/acre is the real story — nearly triple the R-1B density. A 25-ft-wide lot at 3,500 SF fits a narrow 2-story home. The 2023 code added the third story, which changes the math: 3 floors on a 1,400 SF footprint = 3,600+ SF of living space. Corner lots can add a 2,000 SF cafe or shop — that's a live/work play on a residential lot.

R-2

Residential Compact

Boise's missing middle district. Duplexes through apartments all permitted by right. 4 stories, 45 ft, 2,500 SF minimum lots. This is where small multifamily pencils.

What you can build

  • Single-family detached or attached
  • Duplex, triplex, fourplex
  • Multifamily apartments
  • Townhouses
  • Cottage village
  • Live/work units
  • ADU (up to 900 SF)
  • Neighborhood cafe/retail (up to 2,000 SF)
  • Standalone commercial over 2,000 SF
  • Industrial
  • Drive-throughs

Key numbers

Height
4 stories / 45 ft
Lot min
2,500 SF
Width
20 ft avg
Coverage
Not specified
Front
10 ft (remainder), 20 ft (garage/entry)
Side
5 ft or 10 ft interior, 15 ft street side
Rear
15 ft

What this means in practice

R-2 is the developer play in Boise. Multifamily by right, no maximum density — your unit count is limited only by lot coverage, height, setbacks, and parking. On a 10,000 SF lot at 4 stories, you can fit 8-12 units depending on unit mix. The 50% parking reduction for projects with 5+ units near transit (25% affordable at 80% AMI) dramatically improves the math. Neighborhood transition rules require stepping back above 35 ft when adjacent to R-1 zones.

R-3

Residential Urban

Boise's densest residential district. 50-ft height, 1,500 SF minimum for attached units. No density cap. Built for urban apartment and townhouse projects near downtown and BSU.

What you can build

  • Single-family attached or detached
  • Duplex through fourplex
  • Multifamily apartments
  • Townhouses
  • Cottage village
  • Live/work units
  • ADU (up to 900 SF)
  • Boarding house
  • Standalone commercial
  • Industrial
  • Drive-throughs

Key numbers

Height
4 stories / 50 ft
Lot min
1,500 SF (attached), 2,000 SF (other)
Width
20 ft avg
Coverage
Not specified
Front
10 ft (remainder), 20 ft (garage/entry)
Side
5 ft or 10 ft interior, 15 ft street side
Rear
15 ft

What this means in practice

The extra 5 ft of height over R-2 (50 ft vs 45 ft) gives you true 4-story construction with generous floor-to-floor heights. The 1,500 SF minimum for attached units is the density driver — on a quarter-acre site, that's 7 townhouse lots. For apartments, the math is even better: no density cap means a half-acre site at 4 stories can support 30-40 units. Same 50% parking reduction as R-2 if you hit the affordability threshold.

Mixed Use

7 districts in Boise

MX-1

Mixed-Use Neighborhood

Neighborhood activity centers with small-scale commercial and residential. No minimum lot size, no density cap, 0-ft front setback allowed. The lowest-intensity MX district.

What you can build

  • Mixed-use (residential + commercial)
  • Apartments
  • Retail and restaurants
  • Office
  • Live/work
  • Hotels
  • Heavy commercial
  • Industrial
  • Auto-oriented uses in most cases

Key numbers

Height
45 ft
Lot min
None
Width
None
Coverage
Not specified
Front
0 ft min, 20 ft max
Side
0 ft interior, 0-20 ft street side
Rear
10 ft

What this means in practice

The 0-ft front setback with 20-ft max build-to is the key: your building must engage the street. No lot minimums and no density cap mean the math is driven entirely by height (45 ft) and parking. A typical MX-1 project: 3-story mixed-use with ground-floor cafe, 6-10 apartments above. Parking goes behind the building — no surface parking between building and street.

MX-2

Mixed-Use General

Community-serving mixed-use at a larger scale than MX-1. Same 45-ft height and 0-ft setbacks, but intended for bigger commercial uses serving a broader area.

What you can build

  • Mixed-use (residential + commercial)
  • Apartments and condos
  • Office buildings
  • Retail and restaurants
  • Hotels
  • Medical offices
  • Heavy industrial
  • Most auto-oriented uses

Key numbers

Height
45 ft
Lot min
None
Width
None
Coverage
Not specified
Front
0 ft min, 20 ft max
Side
0 ft interior, 0-20 ft street side
Rear
10 ft

What this means in practice

MX-2 and MX-1 share the same dimensional standards — the difference is use scale and context. MX-2 sites serve broader markets (grocery-anchored, medical office, mid-size retail). At 45 ft with no density cap, a 1-acre site can support 80-100 apartments over 15,000 SF of commercial. Parking setback is 10 ft from front — keeps lots out of the street view.

MX-3

Mixed-Use Active

Boise's pedestrian-priority mixed-use district. 70-ft height, mandatory active ground floors (60% of frontage), 4-story minimum on sites over 10,000 SF. Found along State Street and other key corridors.

What you can build

  • Large mixed-use buildings
  • Apartments (4+ stories)
  • Office buildings
  • Retail, restaurants, entertainment
  • Hotels
  • Civic and institutional
  • Surface parking between building and street
  • Ground-floor storage or parking on street frontage
  • Industrial
  • Low-density residential on large sites

Key numbers

Height
70 ft
Lot min
None
Width
None
Coverage
Not specified
Front
0 ft min, 20 ft max
Side
0 ft interior, 0-20 ft street side
Rear
10 ft

What this means in practice

The 4-story minimum on sites over 10,000 SF is the tell — the city wants density here. At 70 ft you're building 6-7 stories with efficient floor plates. Active ground floor requirement (60% of frontage) means retail/restaurant/office at street level. On a 1-acre MX-3 site: 120-150 apartments over 20,000 SF of commercial. Structured parking required at this intensity. Enhanced streetscape standards add cost but support retail rents.

MX-4

Mixed-Use TOD Node

Transit-oriented nodes around Boise's four planned transit hubs. Same 70-ft height and active-use requirements as MX-3, designed for maximum density around future transit stations.

What you can build

  • Large mixed-use buildings
  • High-density apartments
  • Office buildings
  • Retail and restaurants
  • Hotels
  • Transit facilities
  • Surface parking between building and street
  • Ground-floor parking on frontage
  • Industrial
  • Auto-oriented commercial

Key numbers

Height
70 ft
Lot min
None
Width
None
Coverage
Not specified
Front
0 ft min, 20 ft max
Side
0 ft interior, 0-20 ft street side
Rear
10 ft

What this means in practice

MX-4 is a bet on Boise's transit future. Same dimensional standards as MX-3 but located at planned transit nodes. If transit materializes, these sites appreciate significantly — reduced parking requirements and higher rents near stations. The 4-story minimum and active ground floor requirements make this an apartment-over-retail play. Buy now at MX-3 pricing before transit premium kicks in.

MX-5

Mixed-Use Downtown

Downtown Boise's most permissive zoning. No height limit, no rear setback, 80% active ground floor required, 4-story minimum. Build lot-line to lot-line with structured or below-grade parking.

What you can build

  • High-rise mixed-use
  • Apartment towers
  • Office towers
  • Hotels
  • Entertainment and cultural venues
  • Retail and restaurants
  • Surface parking on street frontage
  • Industrial
  • Auto-oriented uses
  • Buildings under 4 stories

Key numbers

Height
No limit
Lot min
None
Width
None
Coverage
Not specified
Front
0 ft min, 20 ft max
Side
0 ft
Rear
0 ft

What this means in practice

MX-5 is the play for downtown Boise. No height cap, 0-ft setbacks on all sides, build lot-line to lot-line. The 80% active ground floor and 60% ground-floor transparency requirements create the urban street wall the city wants. Nonresidential facades need a door every 50 ft. On a quarter-acre downtown site with 10+ stories: 200+ apartments or 150,000+ SF of office. Below-grade parking is the standard at this density. MX-5 land trades at a premium — the entitlement justifies it.

MX-U

Mixed-Use University

Specialized district around Boise State University. Height up to 70 ft by right, potentially unlimited with conditions. Designed for student housing, university-serving commercial, and institutional uses.

What you can build

  • Student housing and apartments
  • University-serving retail and restaurants
  • Office and institutional
  • Hotels
  • Mixed-use buildings
  • Heavy commercial
  • Industrial
  • Auto-oriented uses

Key numbers

Height
70 ft (up to unlimited with conditions)
Lot min
None
Width
30 ft frontage
Coverage
Not specified
Front
0 ft
Side
10 ft street side
Rear
20 ft

What this means in practice

MX-U sites near Boise State are student housing gold. The university enrollment drives consistent demand. At 70 ft, you're building 6-7 story student apartments — 4-bed/4-bath units lease at a premium near campus. The 20-ft rear setback is the main constraint on tight parcels. Compare land costs with MX-3 sites nearby — MX-U may carry a premium for the student housing demand.

MX-H

Mixed-Use Health

Specialized district for regional healthcare facilities. 78-ft height, scaled setbacks that increase at 3+ stories. Built for hospital campuses, medical office buildings, and supporting uses.

What you can build

  • Hospitals and medical centers
  • Medical office buildings
  • Senior housing and assisted living
  • Supporting retail and restaurants
  • Mixed-use buildings
  • Heavy industrial
  • General retail (non-healthcare supporting)
  • Auto-oriented commercial

Key numbers

Height
78 ft
Lot min
None
Width
30 ft frontage
Coverage
Not specified
Front
10 ft
Side
5 ft (1-2 stories), 15 ft (3+ stories)
Rear
5 ft (1-2 stories), 15 ft (3+ stories)

What this means in practice

The stepped setbacks are the key detail: 5 ft at 1-2 stories, jumping to 15 ft at 3+ stories. On tight sites, this reduces your upper-floor plate significantly. A 1-acre MX-H site at 78 ft yields a 7-story medical office building — roughly 120,000 SF. St. Luke's and Saint Alphonsus campuses drive demand for MOBs in these zones. Senior housing also pencils well here given the proximity to healthcare.

Industrial

3 districts in Boise

I-1

Industrial Light

Light industrial flex — manufacturing, assembly, warehouse, and tech uses. Minimal setbacks on interior and rear. The workhorse industrial district for Boise's growing tech and logistics sectors.

What you can build

  • Light manufacturing and assembly
  • Warehouse and distribution
  • Tech and R&D facilities
  • Flex office/industrial
  • Data centers
  • Residential
  • Heavy manufacturing with hazardous materials
  • Retail (standalone)

Key numbers

Height
55 ft
Lot min
None
Width
None
Coverage
Not specified
Front
20 ft
Side
0 ft interior, 15 ft street side
Rear
0 ft

What this means in practice

The 0-ft interior and rear setbacks are the advantage — build wall-to-wall on interior lot lines. At 55 ft, high-bay warehouse and multi-story flex are both viable. A 2-acre I-1 site yields ~150,000 SF of warehouse or ~250,000 SF of multi-story flex. Boise's industrial vacancy is tight — spec flex space leases quickly. If an I-1 site is near a growing mixed-use corridor, long-term rezone potential to MX is the upside play.

I-2

Industrial Heavy

Heavy industrial for manufacturing, processing, and large-scale warehouse. Uses involving hazardous substances require a Conditional Use Permit. Same 0-ft interior setbacks as I-1.

What you can build

  • Heavy manufacturing
  • Processing and assembly
  • Large-scale warehousing
  • Outdoor storage
  • Hazardous material uses (CUP required)
  • Residential
  • Retail
  • Hotels

Key numbers

Height
55 ft
Lot min
None
Width
30 ft frontage
Coverage
Not specified
Front
20 ft
Side
0 ft interior, 15 ft street side
Rear
0 ft

What this means in practice

Same dimensional standards as I-1 but allows heavier uses. The CUP requirement for hazardous materials adds 2-3 months to your timeline. Parking setbacks are wider than I-1 (15 ft vs 10 ft front/street). If you don't need heavy industrial uses, I-1 gives you more flexibility with less process.

I-3

Industrial Technology

Technology-focused industrial for high-impact facilities. 150-ft height cap with setbacks that scale 1:1 above 45 ft. Designed for major tech campuses, data centers, and advanced manufacturing near interstate corridors.

What you can build

  • Advanced manufacturing
  • Data centers
  • Tech campuses and R&D
  • Large-scale assembly
  • Supporting office
  • Residential
  • Retail
  • Hotels

Key numbers

Height
150 ft
Lot min
None
Width
30 ft frontage
Coverage
Not specified
Front
45 ft + 1 ft per ft above 45 ft (or 100 ft max)
Side
Same as front
Rear
Same as front

What this means in practice

The sliding-scale setback is the constraint: a 100-ft building needs a 100-ft setback on all sides. On a 5-acre site, that eats significant buildable area. For a 150-ft data center, you need at least 10 acres to make the geometry work. The 20-ft interstate buffer setback matters — most I-3 sites are near I-84/I-184. Boise's growing tech sector (Micron, HP) drives demand for these sites.

Development Bonus Program

In R-2 and R-3 districts, projects with 5+ dwelling units receive a 50% reduction in minimum off-street parking if located within a quarter-mile of a mixed-use zone and 25% of units are affordable at 80% AMI. This is a significant cost savings — at $20,000-40,000 per structured parking space, eliminating half your stalls can save $200,000+ on a 20-unit project. No rezoning or variance needed. Run the pro forma both ways.

Overlay Districts

Historic Design Overlay (HD-O)

Covers Boise's ten designated historic districts. New construction and exterior modifications require Certificate of Appropriateness from the Historic Preservation Commission. Demolition requires review. Adds 1-3 months to your timeline. Contributing structures face the strictest scrutiny — budget for design review costs.

Hyde Park Character Overlay (HC-O)

Protects Hyde Park's historic commercial district along 13th Street. Maintains the mix of commercial, office, and residential. Specific parking standards for the area. If you're developing in Hyde Park, expect community pushback on anything that doesn't match the neighborhood character.

Capitol Boulevard Design Overlay (CD-O)

Recognizes Capitol Boulevard as Boise's ceremonial corridor from the Depot to the Capitol. Enhanced design standards for building facades, landscaping, and streetscape. Development must maintain and enhance the boulevard's special character.

Boise River System Overlay (BR-O)

Protects the Boise River corridor, Greenbelt, and floodway. Restricts development in the 100-year floodplain and requires preservation of fish and wildlife habitat. If your parcel touches the river system, expect significant buildable area reductions and environmental review. Check FEMA maps before making an offer.

Flood Protection Overlay (FP-O)

FEMA flood zone compliance. Determines base flood elevation, foundation requirements, and insurance costs. Floodway vs. flood fringe makes a major difference in feasibility — floodway parcels are effectively unbuildable for most uses.

Hillside Development Overlay (HS-O)

Applies to parcels with slopes of 15% or greater — common in Boise's North End and foothills. Requires Hillside Development Checklist with applications. Limits grading, requires geotechnical studies, and may restrict building footprint. Construction costs run 20-40% higher on hillside sites.

Wildland Urban Interface Overlay (WUI-O)

Covers foothills and areas at wildfire risk. Property owners must maintain defensible space. Fire-resistant construction materials required. Affects insurance costs significantly. Two types: intermix (houses in wildland vegetation) and interface (development abutting wildland). Common in East Boise and foothills subdivisions.

Airport Influence Overlay (AI-O)

Noise and height restrictions near Boise Airport (BOI). Limits residential density in high-noise zones and imposes building height caps near runways. Check the overlay boundary before pursuing residential projects in southwest Boise — noise disclosure requirements affect marketability.

Frequently Asked Questions

How do I check zoning for a specific property in Boise?

Use the City's Zoning Atlas at arcgis.com or the Open Data Portal at opendata.cityofboise.org. Enter an address to see the base district and any overlays. The City's Planning & Development Services counter can confirm zoning and overlay status.

What changed with the 2023 Modern Zoning Code?

Boise replaced its 1966-era code with a modern framework. Key changes: new district names (R-1A/B/C replaced old R-1 subdivisions, MX-1 through MX-5 replaced commercial zones), ADU size increased to 900 SF with no parking requirement, duplexes allowed in R-1 zones via CUP, no density maximums in mixed-use zones, and 0-ft front setbacks in all MX districts. If you're working with old zone designations (R-1, C-1, C-2), the city has a conversion table.

Can I build an ADU in Boise?

Yes, in all residential districts (R-1A through R-3). Up to 900 SF, maximum 2 bedrooms, no additional off-street parking required, no owner-occupancy requirement. Detached or basement units are permitted by right — no CUP needed. This is one of the most permissive ADU policies in the Mountain West.

What's the difference between R-2 and R-3?

Both allow multifamily by right with no density cap. R-3 gives you 5 extra feet of height (50 ft vs 45 ft), lower minimum lot size for attached units (1,500 SF vs 2,500 SF), and is generally closer to downtown and BSU. For most projects, R-2 and R-3 produce similar unit counts — the height difference matters most for 4-story wood-frame buildings where floor-to-floor height is tight.

How do the mixed-use zones compare?

MX-1 and MX-2: 45 ft, neighborhood/community scale. MX-3 and MX-4: 70 ft, 4-story minimum on large sites, 60% active ground floor required. MX-5: no height limit, 80% active ground floor, 0-ft setbacks on all sides. All MX zones have no density cap and no minimum lot size. The intensity steps up from MX-1 (neighborhood cafe) to MX-5 (downtown tower).

What triggers design review in Boise?

The Historic Design Overlay (HD-O) triggers Certificate of Appropriateness review for exterior modifications. Character overlays (Hyde Park, Capitol Boulevard) have district-specific design standards. In I-3 zones, buildings over 45 ft in internal areas require design review. MX-5 has ground-floor transparency and activation requirements but no discretionary design board — compliance is standards-based.

Is my property in the City or Ada County?

Critical distinction. The City uses the 2024 Modern Zoning Code (R-1A through I-3). Unincorporated Ada County uses its own zoning ordinance with different districts and standards. Check jurisdiction on the GIS map. City annexation can change your zoning — if you're in the county near city limits, explore annexation as a path to higher-intensity entitlements.

Get the full property profile for
any address in Boise

Permitted uses, setbacks, density, buildable area, overlays, and nearby development activity — for a specific parcel, not just the district.