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Zoning certificate · Planning application

Approved: Converting detached garage into one accessory dwelling unit

The city approved a zoning certificate on Feb. 20 to convert an existing single-story detached accessory building into a one-bedroom, one-bathroom unit of about 586.5 square feet. The owners plan to use it for family or guests, not as a rental.

ApprovedCZC25-00244Filed Dec. 2, 2025West Valley · 9641 W Cook Ln+1 related filing
Site plan for Approved: Converting detached garage into one accessory dwelling unit
Site plan from the application documents.
Pin at the reported location; the shaded outline is the primary parcel (Ada County).

From the filing

The application's description as it appears in City of Boise's record. See the official record

The project converts a single-story detached accessory structure at 9641 W Cook Lane in Boise into an accessory dwelling unit of about 586.5 square feet with one bedroom and one bathroom. A carport attached to the existing single-family house provides the one required parking space. The city approved the zoning certificate on February 20, 2026.

ADU

Project name on file: 9641 W COOK LN

Timeline

  1. March 3, 2026

    Appeal Period: Completed

  2. Feb. 20, 2026

    Review Complete: Completed

  3. Feb. 20, 2026

    Current Planning: Complete

  4. Feb. 4, 2026

    Current Planning: In Review

  5. Feb. 4, 2026

    Assign Reviewers: Completed

  6. Jan. 22, 2026

    Review Complete: Corrections Required

  7. Jan. 22, 2026

    Current Planning: Corrections Required

  8. Jan. 16, 2026

    Current Planning: In Review

  9. Jan. 16, 2026

    Assign Reviewers: Completed

  10. Jan. 15, 2026

    Fee Payment: Payment Received

  11. Jan. 14, 2026

    Prescreen Review: Passed

  12. Jan. 12, 2026

    Prescreen Review: In Progress

  13. Jan. 9, 2026

    Prescreen Review: Corrections Required

  14. Jan. 6, 2026

    Prescreen Review: In Progress

  15. Dec. 29, 2025

    Prescreen Review: Corrections Required

  16. Dec. 26, 2025

    Prescreen Review: Corrections Required

  17. Dec. 26, 2025

    Prescreen Review: In Progress

  18. Dec. 18, 2025

    Prescreen Review: Corrections Required

  19. Dec. 15, 2025

    Prescreen Review: In Progress

  20. Dec. 11, 2025

    Prescreen Review: Corrections Required

  21. Dec. 10, 2025

    Prescreen Review: In Progress

  22. Dec. 2, 2025

    Application Submittal: ePlanReview

  23. Dec. 2, 2025

    Application filed

Documents

Site plans

  • One-page site plan drawing with building elevations; the extracted text is mostly garbled OCR from the drawing, so details are not legible.

    Feb. 4, 2026 · 1 page · 713 KB · PDS-Maps and Drawings

    Download Site plan with elevations
  • Single-page site plan map from an internet mapping site, marked as a general reference output that may not be accurate or reliable and is not for navigation.

    Jan. 22, 2026 · 1 page · 1.3 MB · PDS-Maps and Drawings

    Download Site plan

Plans

  • Aerial photo map from an internet mapping site with parcel, road and address layers, dated Jan. 15, 2026, for a zoning certificate application.

    Feb. 4, 2026 · 1 page · 622 KB · PDS-Maps and Drawings

    Download Aerial image map
  • Feb. 4, 2026 · 1 page · 588 KB · PDS-Maps and Drawings

    Download Floorplan
  • Feb. 4, 2026 · 1 page · 661 KB · PDS-Maps and Drawings

    Download Setbacks map
  • Aerial photo map from an internet mapping site with parcel, road and address layers, dated Jan. 15, 2026, for a zoning certificate application.

    Jan. 22, 2026 · 1 page · 622 KB · PDS-Maps and Drawings

    Download Aerial image map
  • Jan. 22, 2026 · 1 page · 289 KB · PDS-Maps and Drawings

    Download Floorplan
  • Jan. 22, 2026 · 1 page · 661 KB · PDS-Maps and Drawings

    Download Setbacks map
  • Jan. 22, 2026 · 1 page · 281 KB · PDS-Photos

    Download Elevations, sheet 1

Project narrative

  • Applicant explains the detached garage was converted to living space over time and seeks approval to make it an accessory dwelling unit for family or guests.

    Feb. 4, 2026 · 1 page · 286 KB · PDS-Letter of Intent

    Download Letter of intent for garage-to-ADU conversion
  • Applicant explains the detached garage was converted to living space over time and seeks approval to make it an accessory dwelling unit for family or guests.

    Jan. 22, 2026 · 1 page · 286 KB · PDS-Letter of Intent

    Download Letter of intent for garage-to-ADU conversion

Decisions

Notices

  • City of Boise notice that staff approved an internal conversion for an accessory dwelling unit under the zoning ordinance, with appeal instructions and a March 2, 2026 deadline.

    Feb. 18, 2026 · 2 pages · 814 KB · PDS-Legal Notice

    Download Notice of approval for accessory dwelling unit conversion

Application

Photos

  • A single site photograph taken January 15, 2026, filed with the zoning certificate application.

    Feb. 4, 2026 · 1 page · 281 KB · PDS-Photos

    Download Site photo 1
  • Feb. 4, 2026 · 1 page · 307 KB · PDS-Photos

    Download Site photo 2
  • Photo document showing elevations, filed with the zoning certificate application; the text is only a filing date and case reference.

    Jan. 22, 2026 · 1 page · 307 KB · PDS-Photos

    Download Elevations, sheet 2

Correspondence

  • ACHD finds no adjacent street improvements required and lists traffic impact fee, driveway approach permit, and right-of-way conditions for the applicant.

    Feb. 24, 2026 · 3 pages · 201 KB · PDS-Agency Comments

    Download Ada County Highway District comments
  • Building Division notes that converting garage space to living space must meet current building code, often requiring foundation, insulation, attic ventilation and smoke detection upgrades; not a full plan review.

    Feb. 20, 2026 · 1 page · 66 KB · PDS-Agency Comments

    Download Building Division comments
  • Fire Marshal review finds no comments on the zoning certificate, noting IBC, IFC and Boise City Code requirements will apply at building permit stage.

    Feb. 20, 2026 · 1 page · 151 KB · PDS-Agency Comments

    Download Boise Fire Department comments
  • Boise Parks and Recreation, reviewing with Community Forestry, has no comments because no existing trees or landscaping will be affected.

    Feb. 20, 2026 · 1 page · 57 KB · PDS-Agency Comments

    Download Parks and Recreation comments
  • Public Works requires connection to the central sanitary sewer, notes sewer capacity fees may be due at building permit, and conditions final sewer plan approval.

    Feb. 20, 2026 · 1 page · 65 KB · PDS-Agency Comments

    Download Public Works sewer comments
  • Veolia requires a separate water service and meter for the new ADU, and a site plan must be submitted to Veolia for review and approval.

    Feb. 20, 2026 · 1 page · 330 KB · PDS-Agency Comments

    Download Veolia Water Idaho comments

Other documents

  • Noticing radius map

    Feb. 18, 2026 · 522 KB · PDS-Maps and Drawings

  • Transmittal sheet

    Feb. 6, 2026 · 136 KB · PDS-Transmittal Agencies

  • Printout of the county assessor's parcel details (owner, legal description, zoning code, acreage) for the property, dated October 2025.

    Feb. 4, 2026 · 2 pages · 103 KB · PDS-Other Small Docs

    Download Ada County assessor property record
  • Veolia Water Idaho reports water pressure and flow available at the site (50 PSI at average demand, 1000 GPM at 20 PSI residual) for fire sprinkler design.

    Feb. 4, 2026 · 2 pages · 698 KB · PDS-Other Small Docs

    Download Fire flow availability letter from Veolia Water
  • Statement of legal interest

    Feb. 4, 2026 · 359 KB · PDS-Statement of Legal Interest

  • Printout of the county assessor's parcel details (owner, legal description, zoning code, acreage) for the property, dated October 2025.

    Jan. 22, 2026 · 2 pages · 103 KB · PDS-Other Small Docs

    Download Ada County assessor property record
  • Veolia Water Idaho reports water pressure and flow available at the site (50 PSI at average demand, 1000 GPM at 20 PSI residual) for fire sprinkler design.

    Jan. 22, 2026 · 2 pages · 698 KB · PDS-Other Small Docs

    Download Fire flow availability letter from Veolia Water
  • Statement of legal interest

    Jan. 22, 2026 · 359 KB · PDS-Statement of Legal Interest

  • Receipt

    Jan. 15, 2026 · 135 KB · PDS-Receipts

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