Zoning › Idaho › Canyon County › Nampa

Nampa, ID Zoning

Euclidean-zoning. 15 districts · 6 overlays · 7 applicable state preemptions.

Overview

Code type
euclidean
Naming convention
—

Primary mechanism is euclidean (RS, RA, RD, RML, RMH, RP, HC, GB, BN, BC, BF, IP, IL, IH, AG). Central Nampa (Chapter 15) implements a separate Form-Based Code for the downtown core with five form districts (CH, CD, C11, C16, CR) — treated as a distinct downtown overlay rather than whole-city form-based. City uses PUDs as a parallel development path (Chapter 26). Chapter 31 establishes eight Specific Area Plan overlays.

Worth knowing
  • RS has 8 density subdistricts (RS-22 through RS-4) where the number encodes minimum lot size in square feet. RS-22 = 22,000 sf min; RS-4 = 4,000 sf min. Numbers are NOT in thousands. §10-8-5.B.
  • Chapter 15 establishes a complete Form-Based Code (FBC) for the Central Nampa area with 5 form districts (CH, CD, C11, C16, CR). The FBC replaces standard §10-3-2 land-use controls for properties within its boundary. §10-15-3.A.
  • BF (Freeway Business) adopts BC (Community Business) standards wholesale per §10-17 — no separate dimensional standards.

+ 7 more in Quirks & notes

Districts

com 4res_sf 3res_mf 3ind 3mu 1spec 1
CodeNameCategory Min lotHeight CoverageFAR Du/acParking Setbacks F/S/R
RASuburban Residentialres_sf43,560 sf[4]30 ft[5]——1[6]—35[1] / 10[2] / 10[3]
RS-22Single-Family Residential — RS-22res_sf22,000 sf[10]30 ft[11]———2[12]15[7] / 5[8] / 15[9]
RS-7Single-Family Residential — RS-7res_sf7,000 sf[16]30 ft[17]———2[18]15[13] / 5[14] / 15[15]
RDTwo-Family (Duplex) Residentialres_mf6,000 sf[22]30 ft[23]———2[24]15[19] / 5[20] / 15[21]
RMLLimited Multiple-Family Residentialres_mf6,000 sf[28]30 ft[29]———1.5[30]15[25] / 5[26] / 15[27]
RMHMultiple-Family Residentialres_mf6,000 sf[34]65 ft[35]———1.5[36]15[31] / 15[32] / 15[33]
RPResidential Professionalmu6,000 sf[40]————2[41]15[37] / 5[38] / 15[39]
HCHealthcarespec——————20[42] / 10[43] / 10[44]
GB1/GB2Gateway Business — GB1/GB2com——————35[45] / 15[46] / 15[47]
BNNeighborhood Businesscom—30 ft[51]————20[48] / 0[49] / 0[50]
BCCommunity Businesscom——————0[52] / 0[53] / 0[54]
BFFreeway Businesscom——————— / — / —
IPIndustrial Parkind——0.5[58]———25[55] / 0[56] / 0[57]
ILLight Industrialind——————10[59] / 0[60] / 0[61]
IHHeavy Industrialind——————10[62] / 0[63] / 0[64]

Confidence: confirmed partial under review not found

Overlays

AHO
Airport Hazard Overlay — Nampa Municipal Airport
AP
§10-31-3 — Airport Specific Area Plan; Nampa Municipal Airport Zoning Map (City Engineer, November 15, 1971)

Areas within visual approach zone, transitional zone, horizontal zone, and conical zone of Nampa Municipal Airport as shown on the Nampa Municipal Airport Zoning Map. Nonprecision approach zone: 500 ft wide at 200 ft beyond runway end, widening to 2,000 ft at 5,000 ft; slope 20:1. Visual approach zone: 500 ft at 300 ft beyond runway end, widening to 1,250 ft at 5,000 ft; slope 20:1. Horizontal zone: 150 ft above airport elevation with arc radii of 5,000 ft (utility/visual runways) or 10,000 ft (nonprecision instrument runways).

approach_zone_slope20:1 (nonprecision instrument) and 20:1 (visual)
transitional_zone_slope7:1 outward from runway centerline extended
horizontal_zone_height_ft_agl150
utility_visual_arc_radius_ft5000
nonprecision_instrument_arc_radius_ft10000
height_restrictionsStructures and trees within approach, transitional, horizontal, and conical zones must not exceed zone-specific height limits per §10-31-3.B
uses_restrictedHazardous uses incompatible with aircraft operations per §10-31-3
citation§10-31-3 confirmed — full text extracted from cityofnampa.us/DocumentCenter/View/13739/Chapter-31-Specific-Area-Plans
statusconfirmed
FO
Floodplain Overlay — FEMA SFHA
FP
§10-1-2.B (definitions: Floodplain, Floodway, Flood Hazard Area); Nampa participates in NFIP. FEMA Flood Insurance Rate Map applicable.

Areas within the FEMA-designated Special Flood Hazard Area (SFHA) — 1% annual chance flood (100-year flood). Floodway is the channel and adjacent overbank areas; flood fringe is lands outside floodway at or below BFE. Base Flood Elevation (BFE) and floodway determined by hydraulic modeling. §10-1-2.B.

base_flood_elevation_requiredTrue
floodway_definitionChannel + adjacent overbank areas to discharge base flood without cumulative BFE rise beyond designated height. §10-1-2.B.
flood_fringe_definitionLands outside floodway at or below BFE inundated in 1% flood event but not effectively conveying floodwaters. §10-1-2.B.
nfip_participationNampa participates in NFIP; substantial improvement thresholds and BFE compliance required.
moderate_flood_hazardAreas between 1% annual chance and 0.2% annual chance (500-year) flood identified on FIRM. §10-1-2.B.
citation§10-1-2.B confirmed — extracted from Chapter 1 PDF (cityofnampa.us/DocumentCenter/View/13709)
statusconfirmed
CN
Central Nampa Form-Based Code Overlay
DT
§10-15 — Central Nampa Form-Based Code; adopted per Downtown Implementation Plan and Feasibility Study. Five form districts: CH (Central Historic), CD (Central Downtown), C11 (Central 11th Avenue), C16 (Central 16th Avenue), CR (Central Residential).

Properties within the Central Nampa FBC boundary as shown on the form district map (Figure 1.1, §10-15-1.A). Encompasses downtown historic core and surrounding transition areas. Properties are regulated by form district, frontage type, building type, and use — separate from standard Euclidean districts. §10-15-3.A: FBC does not use the standard §10-3-2 land use control schedule.

form_districtsCH (Central Historic), CD (Central Downtown), C11 (Central 11th Avenue), C16 (Central 16th Avenue), CR (Central Residential). §10-15-2.
ch_purposePreserves traditional street grid, pedestrian-oriented character, historic structures; requires continuous street frontage, active ground-floor uses. §10-15-2.A.
cd_purposeHighest-intensity development area; dense, walkable, active ground floors, compact blocks, limited setbacks. §10-15-2.B.
c11_purposeNorthwest gateway into CH and CD; medium to high-density commercial, civic, residential. §10-15-2.C.
c16_purposeMedium-density mix; transition between CD and southeastern neighborhoods along 16th Avenue. §10-15-2.D.
cr_purposeLow-density mix; southwest boundary transition to lower-density neighborhoods. §10-15-2.E.
building_typesGeneral, Limited Bay, Row, Yard, Civic. Permitted by form district and frontage type. §10-15-5.D.
build_to_zoneBTZ identifies area on ground where building facade must be located; expressed as min-to-max offset from ROW property line. §10-15-5.D.1.c.
parking_reducedFBC area has reduced parking requirements per §10-15-8.
cn_zone_parking_exceptionIn CN zone, only residential dwelling units require parking per §10-22-1.A.
citation§10-15 confirmed — full text extracted from Chapter 15 PDF (cityofnampa.us/DocumentCenter/View/13723)
statusconfirmed
SAP
Specific Area Plan Overlays (8 overlays)
SPD
§10-31 — Specific Area Plans. Eight SAPs: Airport (§10-31-3), Highway 16 (§10-31-4), Highway 20/26 (§10-31-5), Midland Corridor (§10-31-6), Southwest Nampa (§10-31-7), Southeast Nampa (§10-31-8), Central Nampa (§10-31-9, implemented via §10-15 FBC), Old Nampa Neighborhood (§10-31-10).

Properties within the eight SAP overlay districts shown on the Nampa Future Land Use Map. Each SAP establishes an overlay district boundary providing guidance for land use, site design, and building design where standard Euclidean zoning cannot achieve desired results. §10-31-1.

sap_count8
sap_namesAirport; Highway 16; Highway 20/26; Midland Corridor; Southwest Nampa; Southeast Nampa; Central Nampa; Old Nampa Neighborhood
applicabilitySAP designations may use land use names differing from FLUM; FLUM designations best-matching the SAP are applied within the overlay boundary. §10-31-2.A.
standards_scopeSAPs provide enhanced site design/layout, land use, streetscape, recreational elements, area themes, circulation, infrastructure, transportation, architectural design standards. §10-31-2.B.
cn_sapCentral Nampa SAP (§10-31-9) is implemented through the Chapter 15 Form-Based Code.
airport_sapAirport SAP (§10-31-3) codifies airport hazard zones, height restrictions, and approach zone definitions for Nampa Municipal Airport.
citation§10-31 confirmed — full text extracted from Chapter 31 PDF (cityofnampa.us/DocumentCenter/View/13739)
statuspartial
what_is_confirmedEight SAP names, overlay district structure, airport hazard zones, CN FBC reference. §10-31-2 through §10-31-3.
what_is_missingDetailed dimensional standards for Hwy 16, Hwy 20/26, Midland Corridor, Southwest/Southeast Nampa, and Old Nampa Neighborhood SAPs — these require access to the separate SAP plan documents not fully extracted from Chapter 31 PDF.
ONN
Historic Preservation — Old Nampa Neighborhood SAP
HP
§10-31-10 — Old Nampa Neighborhood Specific Area Plan overlay.

Properties within the Old Nampa Neighborhood Specific Area Plan overlay boundary as shown on the Nampa Future Land Use Map. §10-31-10.

purposeSpecific Area Plan providing guidance for land use, site design, and building design in the Old Nampa Neighborhood where standard zoning cannot achieve desired results.
full_standards_retrieval_statusChapter 31 PDF text was extracted but detailed SAP standards sections beyond §10-31-3 (Airport) were not fully visible in the extracted text. Full detailed standards for ONN are not_captured from primary source.
citation§10-31-10 confirmed as existing per §10-31 chapter TOC extracted from cityofnampa.us/DocumentCenter/View/13739
statuspartial
what_is_confirmedOld Nampa Neighborhood SAP exists per §10-31-10.
what_is_missingDimensional standards, design guidelines, and geographic trigger details not captured from primary source.
not_applicable
Floodplain — Not found as standalone overlay district
FP
FEMA NFIP standards implemented through definitions in §10-1-2.B rather than a separate overlay chapter. See primary Floodplain Overlay entry above.

FEMA SFHA per §10-1-2.B definition.

search_performedSearched Title 10 chapters 1–35 for a standalone floodplain overlay chapter. Floodplain is addressed via definitions in §10-1-2.B and NFIP participation; there is no separate standalone overlay chapter analogous to some other cities.
citation§10-1-2.B
statusnot_applicable
reasonFloodplain handled via §10-1-2.B definitions and NFIP participation rather than a standalone overlay chapter.

State preemptions

ID LLUPA §67-6501 et seq. — Frameworkapplies
Qualifying condition
LLUPA applies always to all Idaho municipalities. Nampa population ~125,000 (2023 est.) — well above any LLUPA population trigger. Comp plan required; zoning must be consistent with it (§67-6509). 300-ft mailed notice required for rezones.
Effect
LLUPA is simultaneously enabling act and preemption ceiling. Nampa's zoning authority derives entirely from I.C. Title 67 Ch. 65. Inconsistency with adopted comp plan is the primary basis for challenge.
ID §67-6539 — Short-Term Rental Preemption (HB 583, 2026, effective 2026-07-01)applies
Qualifying condition
§67-6539 applies always to all Idaho municipalities — no population threshold. Nampa may not ban STRs in residential zones where similar residential uses are allowed. HB 583 (2026) strengthens preemption effective 2026-07-01: classifies STRs as nontransient residential use, waives add-on parking minimums specific to STRs, waives mandatory professional management, waives STR-specific fire inspection beyond IRC/IBC, waives sprinkler requirements beyond IRC.
Effect
Nampa RS, RD, RML, RMH, RP districts must permit STRs where similar residential uses are allowed. City retains authority to regulate for health/safety (noise, parking tied to IBC, occupancy per IBC) and require registration.
ID §67-6509A — Manufactured Housing Parity (HB 800, 2026, extended effective 2026-07-01)applies
Qualifying condition
§67-6509A applies always to all Idaho municipalities — no population threshold. Nampa may not exclude HUD-code manufactured homes from any zone where single-family detached is permitted. HB 800 (2026) extends parity to manufactured duplexes in multi-family zones and single-section manufactured homes ≥400 sf in single-family zones, effective 2026-07-01.
Effect
RS, RA districts must permit HUD-code manufactured homes. RML, RMH, RP districts must permit manufactured duplexes (≥800 sf min unit size) and single-section manufactured homes (≥400 sf), effective 2026-07-01. City may impose permanent foundation, removal of transport hardware, and uniformly-applied design compatibility standards.
ID SB 1354 — ADU By-Right (Cities ≥10,000, effective 2026-07-01)applies
Qualifying condition
SB 1354 triggers for cities ≥10,000 population. Nampa population ~125,000 (2023 est.) — 12.5× threshold. Applies.
Effect
One ADU permitted by right per lot in RS districts. Discretionary review for ADUs waived. Mandatory parking minimums for ADUs prohibited absent documented infrastructure constraints.
ID SB 1352 — Starter-Home Subdivisions (Cities ≥10,000, effective 2026-07-01)applies
Qualifying condition
SB 1352 triggers for cities ≥10,000 population. Nampa population ~125,000 (2023 est.) — 12.5× threshold. Applies.
Effect
Min lot size capped at 1,500 sf for qualifying starter-home subdivisions. Up to 12 du/ac required on starter-home developments ≥4 acres. Preempts RS subdistrict minimums for qualifying projects.
ID HB 707 — Administrative Lot Splits (Cities ≥10,000, effective 2026-07-01)applies
Qualifying condition
HB 707 triggers for cities ≥10,000 with existing residential structure. Nampa population ~125,000 — threshold met.
Effect
Nampa must provide administrative path for lot splits on parcels containing existing residential structures. Bypasses full subdivision platting procedure; underlying zoning compliance still required.
ID HB 585 — Permit Inspection Shot-Clock (Statewide, effective 2026-07-01)applies
Qualifying condition
HB 585 applies statewide regardless of city size. Nampa is an Idaho city — applies.
Effect
Nampa building inspections must occur within 6 business days. Applicant may invoke third-party inspector if city misses deadline.

Adopted building codes

Statewide; extensive NEC amendments

IBC
2018
IRC
2024
NEC
2023
IFC
2018
IECC (Residential)
2018
IECC (Commercial)
2018

Click a code label to open its state-by-state adoption atlas.

Amendment history

DateKindCitation
2026-05-27retrieved at
2026-04supplement effectiveTitle 10 complete document last updated 04/2026 per city website chapter download page
2026-01-01amendment effectiveJanuary 2026 Council adoption of code changes impacting multiple Title 10 chapters; announced at cityofnampa.us/1491

Quirks & notes

  • RS has 8 density subdistricts (RS-22 through RS-4) where the number encodes minimum lot size in square feet. RS-22 = 22,000 sf min; RS-4 = 4,000 sf min. Numbers are NOT in thousands. §10-8-5.B.
  • Chapter 15 establishes a complete Form-Based Code (FBC) for the Central Nampa area with 5 form districts (CH, CD, C11, C16, CR). The FBC replaces standard §10-3-2 land-use controls for properties within its boundary. §10-15-3.A.
  • BF (Freeway Business) adopts BC (Community Business) standards wholesale per §10-17 — no separate dimensional standards.
  • Most Nampa residential districts have no maximum lot coverage or FAR for principal structures. Coverage maximums apply to industrial (IP: 50%/60%) but are absent from most residential and commercial zones.
  • RMH height capped at 65 ft but requires Council approval beyond that; near single-family zones limited to 30 ft for first 50 ft depth. §10-12-3.
  • Parking for single-family requires at least 1 covered space in RS zoned areas. Multi-family: 1BR=1.5/du (1 covered), 2BR+=2/du (1 covered); 0.25/du guest parking required. Covered spaces reserved per unit. §10-8-9, §10-22-6.B.
  • Chapter 31 establishes 8 Specific Area Plan overlays as separate overlay districts. Central Nampa SAP is implemented through Chapter 15 FBC. Airport SAP codifies FAA-derived height restrictions for Nampa Municipal Airport. §10-31.
  • IL and IH have height-stepback rule: front setback increases 1 ft per 1 ft of height above 35 ft. §10-19-5.C, §10-20-5.C.
  • Idaho is a Dillon Rule state. LLUPA (I.C. Title 67 Ch. 65) is simultaneously enabling act and preemption ceiling. March 2026 housing reform package (HB 583, SB 1352, SB 1354, HB 707, HB 800, HB 585) materially expanded state preemptions — multiple laws effective 2026-07-01 apply to Nampa.
  • v1 record was template-bleed: fabricated districts (R-1/R-2/C-1/C-2/I-1/I-2 not present in Nampa code), fabricated values marked confidence='i', no primary source citations. All v1 district data replaced with primary-source research.

Formulas

Definitions

height
Grade to ceiling of top floor of structure. §10-8-3 (RS), §10-7-2 (RA), §10-10-3 (RD), §10-11-3 (RML), §10-12-3 (RMH), §10-14-2 (BN).
lot_coverage
Buildings may not exceed stated fraction of lot area. IP: 50% freeway-adjacent / 60% other. Residential zones have no stated coverage maximum except as noted.
far
Not explicitly defined in most Nampa districts; no FAR maximum stated.
du_ac
Gross density in dwelling units per acre referenced in Comp Plan future land use designations (LDR 1.01–2.5 du/ac, MDR 2.51–8 du/ac, HDR 8+ du/ac). District lot-size tables implement density indirectly.
setback_front
Front lot line (or future ROW) to building.
setback_side
Side lot line to building.
setback_rear
Rear lot line to building.
parking
Off-street spaces per dwelling unit. §10-22-6.B.

Massing explorer

Interactive 3D comparison across every district. Drag to orbit, scroll to zoom, use the slider to walk districts, and toggle applicable overlays in the right-side panel.

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— /unit
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District Category Height FAR Coverage Setbacks Parking Density Min lot Overlays

Sources & references

Primary source
City of Nampa Title 10 — Planning and Zoning
retrieved 2026-05-27
Citations
  1. [1] §10-7-4.D
  2. [2] §10-7-4.E
  3. [3] §10-7-4.E
  4. [4] §10-7-4.A
  5. [5] §10-7-2
  6. [6] §10-7-4.B
  7. [7] §10-8-5.A
  8. [8] §10-8-5.A
  9. [9] §10-8-5.A
  10. [10] §10-8-5.B
  11. [11] §10-8-3
  12. [12] §10-8-9; c§10-22-6.B
  13. [13] §10-8-5.A
  14. [14] §10-8-5.A
  15. [15] §10-8-5.A
  16. [16] §10-8-5.B
  17. [17] §10-8-3
  18. [18] §10-8-9; c§10-22-6.B
  19. [19] §10-10-5.A
  20. [20] §10-10-5.A
  21. [21] §10-10-5.A
  22. [22] §10-10-5.D
  23. [23] §10-10-3
  24. [24] §10-22-6.B
  25. [25] §10-11-4.A
  26. [26] §10-11-4.A
  27. [27] §10-11-4.A
  28. [28] §10-11-4.D
  29. [29] §10-11-3.A
  30. [30] §10-22-6.B
  31. [31] §10-12-4.A
  32. [32] §10-12-4.A
  33. [33] §10-12-4.A
  34. [34] §10-12-4.D
  35. [35] §10-12-3.A
  36. [36] §10-22-6.B
  37. [37] §10-13-4.A
  38. [38] §10-13-4.A
  39. [39] §10-13-4.A
  40. [40] §10-13-4.D
  41. [41] §10-22-6.B
  42. [42] §10-9-4
  43. [43] §10-9-4
  44. [44] §10-9-4
  45. [45] §10-4-3
  46. [46] §10-4-3
  47. [47] §10-4-3
  48. [48] §10-14-3.C
  49. [49] §10-14-3.D
  50. [50] §10-14-3.D
  51. [51] §10-14-2
  52. [52] §10-16-4.C
  53. [53] §10-16-4.C
  54. [54] §10-16-4.C
  55. [55] §10-18-6.C
  56. [56] §10-18-6.D
  57. [57] §10-18-6.D
  58. [58] §10-18-6.B
  59. [59] §10-19-5.C
  60. [60] §10-19-5.D
  61. [61] §10-19-5.D
  62. [62] §10-20-5.C
  63. [63] §10-20-5.D
  64. [64] §10-20-5.D

Research status

Publication gates

primary url presentpassedsource.primary_url = https://www.cityofnampa.us/1491/Zoning-Information (city-hosted, HTTPS, not an aggregator). All chapter PDFs retrieved from cityofnampa.us/DocumentCenter. Secondary URL is Municode mirror (403 Cloudflare but identified as legitimate codification host).
no aggregator citedpassedScan clean. No Zoneomics / Steadily / SitePlanGuide / SitePlanCreator / Propwire / Zonara / Unzoned references. All citations reference primary Nampa City Code section numbers (§10-x-y), city DocumentCenter URLs, Idaho statutes (I.C. §67-xxxx), or Idaho state overlays file.
confidence tags full formpassedAll confirmed fields carry §-citations in full form (e.g., c§10-8-3, c§10-7-4.A, c§10-9-4). Fields not found from primary source carry status=not_found with search_performed, or status=partial with what_is_confirmed + what_is_missing. No bare [confirmed] tags. 67 confirmed values with §-citations; 14 not_found with search_performed.
overlays have parameters trigger confidencepassed6 overlay entries. Airport (c§10-31-3): trigger, params (7 keys), base_interaction, status=confirmed. Floodplain (c§10-1-2.B): trigger, params (5 keys), status=confirmed. Central Nampa FBC (c§10-15): trigger, params (10 keys), status=confirmed. SAP overlays (p§10-31): trigger, params, status=partial with what_is_confirmed + what_is_missing. FP not_applicable: reason stated. All have name/code/type/ordinance/trigger/params/base_interaction/status/confidence.
preempt section city specificpassedIdaho is not in the Gate 5 mandatory active-preemption state list (CA/TX/FL/OR/WA/CO/MN/MT/UT/AZ/NJ/CT). However, Idaho overlays.json exists with substantive 2026 housing-reform preemptions. state_preemptions_applicable[] populated with 7 entries, each carrying city-specific qualifying_condition_checked with numeric inputs, threshold comparison, and applies=true/false determination. No link-stubs.

Data quality

82%completeness
Documented gaps
  • RS subdistricts RS-22, RS-18, RS-15, RS-12, RS-8.5, RS-6, RS-4 have same dimensional standards as RS-7 (setbacks, height) but different min lot sizes; represented by RS-22 and RS-7 exemplars.
  • Agricultural (AG), University (U), and Gateway Business GBE sub-district not individually documented as full district records.
  • Central Nampa FBC detailed per-form-district dimensional standards (BTZ widths, build-to-line ranges, height stepbacks) not fully extracted — complex FBC table format in large PDF.
  • Chapter 31 SAP detailed standards for Hwy 16, Hwy 20/26, Midland Corridor, SW/SE Nampa, and Old Nampa SAPs not fully extracted.
  • Non-residential parking ratios in §10-22-6.B not fully captured (large table; residential portion captured).

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