Planning project · Planning application
Garage addition and new retaining walls proposed for single-family home
The plan adds an attached garage for two to three cars with a covered deck and replaces three front retaining walls. The city says it is a hillside project, so soils and slope reports may be required. Staff would review it administratively.

From the filing
The application's description as it appears in City of Boise's record. See the official record
Retaining walls & garage addition
Project name on file: 141 E HEARTHSTONE DR
Timeline
Oct. 13, 2026
7 documents added
July 31, 2026
Concept Review Complete: CR Complete - Type 2
July 22, 2026
Concept Review Complete: Engineering Preview
July 22, 2026
Concept Review Complete: Engineering Preview Complete
Based on submitted documents and limited overview of the property, a determination has been made that this project will be a Category II Hillside project due to slope, erosion-prone soils, unstable soils, earth movement, and other geologic and hydrologic hazards. In addition to the already submitted documents (please submit them with subsequent applications), additional documents may be required during the CFH Review process.Additional documents that you can expect to provide will be a site-specific geotechnical report with the possibility of a global slope stability analysis (please see the Agency Comment for Hillside Retaining Wall Permitting within this PLN); structural calculations for any retaining wall system that is greater than four feet in height from top of foundation to top of wall, that has more than one wall when the interior horizontal distance between the walls is less than 10 feet and the total height of all walls exceeds four feet, that has a surcharge, that has a backslope greater than three feet horizontal to one foot vertical, or that has structural components (these requirements will be assessed again at the time of occupancy); and civil plans. Please refer to the Hillside Development Requirements for Technical Reports for grading & drainage plan and geotechnical report requirements.A subgrade inspection by a geotechnical firm will be required at the time of construction once the subgrade is exposed and prior to placement of foundation materials or forms/rebar. A report of the inspection will need to be submitted to and accepted by PW Hillside (HillsideDrainage@cityofboise.org) before scheduling your inspection with the Building Department and receiving final occupancy.NOTE: The hazards of developing and building on a property, especially in the Boise foothills, are well known. It is the responsibility of the applicant/owner’s design, geological, and engineering professionals, not the City, to identify, address, and mitigate any hazards to the site. Satisfying these Conditions of Approval is for limited [City purpose] only and should not be relied on for design, geological or engineering purposes. Developer will comply with all requirements of Boise City Hillside Development Code Sections or submit evidence satisfactory to the Boise City Engineer that the proposed development is exempt from the requirements therein stated due to location, topography and/or the absence of adverse conditions associated with slope stability, ground water, erosion and sedimentation.If you would like to discuss this determination, please contact us at HillsideDrainage@cityofboise.org. Please include your application number and address in the subject line.
July 17, 2026
Application Submittal: Online
July 17, 2026
Application filed
Documents
Plans
- Download Concept A review set for setbacks and site limitations
Architectural review set (Concept A, dated 7.8.2026) with a drawing index, fire and wildland-urban interface notes, and site information including setbacks and building height.
July 17, 2026 · 10 pages · 3.6 MB · PDS-Other Small Docs
- Download Concept B review set for setbacks and site limitations
Architectural review set (Concept B, dated 7.8.2026) with a drawing index, fire and W.U.I. notes, site information, and setback and zoning details for the proposed addition.
July 17, 2026 · 10 pages · 8.5 MB · PDS-Other Small Docs
Project narrative
- Download Concept review summary report
Advisory concept review for a garage addition and retaining wall replacement, flagging the project as a Category II Hillside project and listing expected technical documents.
July 31, 2026 · 3 pages · 460 KB · PDS-Concept Review Summary Report
Application
- Download Planning project application form for garage addition and retaining wall
Application for a front garage addition with covered deck above and replacement of the existing railroad tie retaining wall along the street, in the R-1B zone, with a Hillside Questionnaire required.
July 17, 2026 · 2 pages · 154 KB · PDS-Application
- Download Hillside project questionnaire
Public Works questionnaire answering whether the project involves new grading over 12 inches, an addition, a retaining wall, and a new driveway or parcel changes.
July 17, 2026 · 1 page · 672 KB · PDS-Other Small Docs
Correspondence
- Download Hillside retaining wall permitting guidance
Public Works guidance on when retaining walls in the hillside zone need a determination, slope stability analysis, and planning-code height and setback limits.
July 22, 2026 · 5 pages · 804 KB · PDS-Agency Comments
Other documents
- Download Covenants, conditions and restrictions on setbacks and requirements
Plat document for The Highlands Unit No. 18 with curve data, building setback lines (front 20 feet, sides 7 feet, rear 26 feet) and reference to recorded restrictive covenants.
July 17, 2026 · 14 pages · 1.9 MB · PDS-Other Small Docs

