What Is a Residential Site Plan?

A residential site plan is a scaled, top-down drawing of a parcel of land. It shows where the house, accessory buildings and exterior improvements are positioned in relation to the property boundaries.

A floor plan explains what is happening inside a building. A site plan explains how the building and proposed project fit on the land.

A permit reviewer can use the site plan to understand:

• The complete shape and dimensions of the lot
• The location of the existing residence
• The size and position of the proposed project
• The distances from construction to property lines
• The separation between existing and proposed structures
• How vehicles and pedestrians reach the property
• Whether easements, utilities or site conditions may affect the work

For a broader introduction, read

Everything You Need to Know About a Site Plan
.

Boise Home Projects That May Need a Site Plan

A site plan is commonly needed when residential work changes the building footprint, exterior property layout, access or use of the lot.

When Does Boise Require a Building Permit?

The required permit depends on the type, size and location of the project.

Boise’s homeowner guidance identifies building permits for projects such as:

• New one- and two-family dwellings
• Room additions
• Attached garages, carports and covered porches
• Detached garages or sheds larger than 200 square feet
• Decks more than 12 inches above grade
• Fences more than seven feet high
• Attached patio covers, regardless of size
• Retaining walls four feet or more in height, measured from the bottom of the footing
• Shorter retaining walls supporting a slope or surcharge
• Changes involving structural walls, foundations or major exterior openings

Official resource:

City of Boise Homeowner’s Guide to Residential Construction
.

Small sheds

A garden shed measuring 200 square feet or less may not require a building permit when it is not located in a floodplain.

That does not mean it can be placed anywhere on the property. Boise advises homeowners to confirm planning setbacks, particularly for sheds larger than 120 square feet.

Driveways

Boise’s homeowner guide states that an ordinary driveway may not require a building permit, but Planning and Zoning approval is still needed.

Work involving the curb, sidewalk, street or public right-of-way may require separate approval from the authority responsible for that infrastructure.

What Should a Boise Site Plan Show?

The precise information depends on the proposed work, but Boise’s residential checklists identify several recurring site-plan elements.

Site Plans for Additions and Accessory Buildings

Boise uses its Residential Addition, Alteration and Accessory Building application for many common homeowner projects.

For an addition or detached accessory building, the site plan should show:

• Existing structures and accessory buildings
• The proposed addition or new building
• Balconies and decks
• Driveways and walkways
• Dimensions of the proposed project
• Distances to property lines
• Distances to other buildings
• Adjacent streets
• Lot dimensions matching the recorded plat
• Known easement locations

The amount of supporting documentation depends on the size and complexity of the project.

Official resource:

Boise Residential Addition, Alteration and Accessory Building Checklist
.

New Residential Construction

All new residential construction in Boise requires a building permit and plan-review approval.

For a new house, Boise’s checklist identifies a site plan drawn at a scale of 1 inch equals 20 feet.

The drawing should show:

• The proposed residential structure
• Balconies and decks
• Driveways and walkways
• Dimensions and property-line distances
• Recorded bearings, distances and curve data
• Easement locations
• Required front, side and rear setbacks
• The maximum permitted building height

The complete application may also require:

Official resource:

City of Boise New Residential Submittal Checklist
.

Why Setback Dimensions Matter

A setback is the required or proposed distance between a building and a property boundary.

Setback dimensions help Boise determine whether the project is positioned correctly under the zoning code, recorded subdivision documents and previous planning approvals.

The correct requirement may depend on:

• The property’s zoning district
• The type of residential structure
• Whether the project is attached or detached
• The size and shape of the lot
• Whether the property has multiple street frontages
• The existing location of the house
• Recorded easements
• A planned-unit-development approval
• A subdivision plat or special building envelope
• Historic, floodplain or hillside conditions

Do not copy a setback used for another Boise property without confirming that both parcels are subject to the same requirements.

Official resource:

City of Boise Zoning Code
.

Do Not Guess the Legal Property Boundary

An existing fence, hedge, driveway edge, retaining wall or online aerial image does not necessarily identify the legal property line.

Boundary information may come from:

• A licensed boundary survey
• A recorded subdivision plat
• A deed description
• A previous approved site plan
• Reliable closing documents
• Property records supplied by the owner

An Idaho professional land surveyor may be needed when:

• The project is proposed close to a property line
• Property corners cannot be located
• The parcel is narrow or irregular
• An existing fence appears out of alignment
• A neighbor disputes the boundary
• Available records conflict
• Boise requests verified boundary information

Deck Site Plans

Boise requires a building permit for a deck more than 12 inches above grade.

The site plan should show:

• The existing house and accessory buildings
• The complete proposed deck footprint
• Deck length and width
• Distances to property lines
• Distance to other buildings
• Stairs and landings
• Connection to the house
• Driveways and walkways where relevant

The permit package may also require a framing plan, elevations and section drawings showing:

• Footing locations
• Posts and beams
• Joist size, spacing and direction
• Ledger connections
• Guardrails
• Stairs and handrails
• Height above grade

Engineering may be required for a deck taller than six feet above grade or for a design not covered by the prescriptive residential code.

Patio Covers and Pergolas

An attached patio cover requires a building permit because the new structure transfers loads to the existing house.

A freestanding pergola or gazebo larger than 200 square feet also requires a building permit. Some designs may require engineering because they use pole-type construction rather than conventional light-frame construction.

The site plan should identify:

• The existing residence
• The proposed roof or pergola footprint
• Support-post locations
• Overall dimensions
• Distances to property lines
• Distances to other buildings
• Patios, decks and walkways
• Known easements

The site plan does not determine final post, footing, beam or connection sizes. Those details belong in the construction or engineering drawings.

Detached Garages, Sheds and Greenhouses

Detached garages, sheds and greenhouses larger than 200 square feet generally require a building permit.

The site plan should show:

• The existing house
• Existing accessory buildings
• The proposed building footprint
• Overall length and width
• Distances to every relevant lot line
• Distance to the house and other structures
• Driveway and vehicle access
• Walkways and gates
• Known easements

Supporting permit documents may also include:

• Dimensioned floor plan
• Foundation plan
• Roof-framing plan
• Exterior elevations
• Building sections
• Wall-bracing information
• Structural calculations where required

Retaining Walls, Slopes and Site Levels

A retaining wall may require a permit when it is four feet or more in height, measured from the bottom of the footing to the top of the wall.

Engineering may also be required for a shorter wall supporting sloping soil, a driveway, a building or another surcharge.

The site plan may need to identify:

• The wall location
• Wall length
• Wall height
• Distances to property lines
• Distance to buildings
• Existing and proposed ground levels
• Slopes above and below the wall
• Driveways or structures supported by the wall
• Drainage direction

A drafted site plan can display supplied level information, but it does not replace a topographic survey, geotechnical report or engineered retaining-wall design when those services are required.

Hillside Properties

New residential construction within Boise’s designated Hillside Overlay areas follows additional requirements.

Hillside projects may require information involving:

• Existing and proposed contours
• Building-pad elevation
• Finished-floor elevation
• Cut-and-fill areas
• Retaining walls
• Driveway grade
• Drainage
• Erosion control
• Geotechnical conditions
• Professionally designed foundations

All applicable Planning and Zoning approvals must be completed before the building-permit application is submitted.

Official resource:

City of Boise Hillside New Residential Guide
.

Floodplain Properties

A structure located in a floodplain can require additional review even when the same type of structure would normally qualify for a permit exemption elsewhere.

Depending on the project, required information may include:

• Flood-zone designation
• Floodplain boundaries
• Existing grade
• Proposed finished-floor elevation
• Elevation Certificate
• Letter of Map Revision
• Flood-resistant construction details

For new residential projects, Boise’s checklist identifies an Elevation Certificate or Letter of Map Revision for structures located in a floodplain.

Do not assume that an ordinary unsigned site plan is the only document required for a flood-affected property.

Historic Districts

Building-permit requirements generally remain the same in Boise historic districts, but many exterior projects require separate Planning approval.

Work that may require a Certificate of Appropriateness includes:

• Additions
• Detached garages and accessory structures
• Decks and porches
• Window or siding replacement
• Exterior alterations
• Tree removal
• Demolition

Boise states that the required Certificate of Appropriateness must be obtained before applying for the building permit or beginning work.

The site plan can help show the proposed project’s relationship to the existing house, street, boundaries, access and other structures.

Erosion and Sediment Control

Some Boise home projects require a separate Erosion and Sediment Control review or permit.

Projects that may trigger additional erosion-control requirements include:

• New one- or two-family dwellings
• Accessory dwelling units
• Detached garages
• Swimming pools
• Large additions
• Projects involving substantial excavation
• Projects disturbing significant areas of soil

Depending on the scope, plans may need to show:

• Limits of disturbance
• Construction access
• Soil-stockpile locations
• Sediment barriers
• Drainage routes
• Stabilized areas
• Existing and proposed grades

Confirm the current threshold and submission requirements for the individual project before beginning excavation.

Boise’s Current Residential Building Codes

Boise currently enforces the 2018 International Residential Code for one- and two-family residential construction, subject to state and local amendments.

The city’s currently adopted codes also include:

Official resource:

City of Boise Current Building Codes
.

A site plan does not replace architectural, structural, mechanical, plumbing, electrical or energy-code documents required for the permit.

Submitting Permit Plans Online

Boise uses an online Permitting and Licensing portal for building permits and planning applications.

Applicants create an account, select the appropriate application and upload the required plans and documents.

For new residential construction, the city uses electronic plan review and requires the applicable submission checklist to be uploaded with the application.

For easier electronic review:

• Use clear and descriptive file names
• Keep the property address consistent on every document
• Use the required plan-sheet size
• Draw plans to the required scale
• Make labels and dimensions easy to read
• Clearly distinguish existing and proposed work
• Coordinate the site plan with the floor plans and elevations
• Include the current revision date
• Upload complete revised sheets when responding to comments

Official resource:

City of Boise Permitting and Licensing Portal
.

What to Provide When Ordering Your Site Plan

Reliable property and project information helps produce a clearer drawing and reduces avoidable revisions.

Provide as much of the following as possible:

• Complete Boise property address
• Parcel number
• Current property survey
• Recorded subdivision plat
• Previous approved site plan
• Existing house plans
• Project description
• Proposed structure dimensions
• Desired project location
• Distances to property boundaries
• Photographs of the project area
• Hand-drawn sketch or marked image
• Builder or manufacturer drawings
• Driveway and walkway information
• Known easements
• Utility information
• Retaining-wall details
• Existing or proposed elevations
• Floodplain or hillside information
• Comments received from Boise staff

You can also review our

step-by-step guide to creating a site plan

to understand the information used to prepare a residential drawing.

A Practical Boise Permit Process

Common Boise Site Plan Mistakes

• Showing only the proposed project instead of the complete property
• Leaving out one or more property boundaries
• Failing to show front, side and rear setback dimensions
• Using an existing fence as the assumed legal boundary
• Leaving out balconies, decks, driveways or walkways
• Omitting existing garages, sheds or accessory structures
• Failing to show distances between buildings
• Ignoring recorded easements
• Using lot dimensions that do not agree with the recorded plat
• Failing to distinguish existing and proposed construction
• Using dimensions that conflict with floor plans
• Overlooking floodplain, hillside or historic requirements
• Ignoring erosion-control requirements
• Submitting unreadable electronic files
• Using an outdated plan revision
• Beginning construction before the required permit is issued

Boise Residential Site Plan Checklist

Frequently Asked Questions

Does every Boise home project require a site plan?

No. The required documents depend on the project. Work that creates or enlarges a building footprint, adds an accessory structure, installs a raised deck or affects setbacks is more likely to require a site plan.

Does a shed need a building permit?

A detached shed larger than 200 square feet generally requires a building permit. A smaller shed may still need to comply with zoning setbacks, and a permit may be required when the property is in a floodplain.

Does a Boise deck require a permit?

A building permit is required when a deck is more than 12 inches above grade. The application may require a site plan, framing plan, elevations and construction sections.

Does an attached patio cover require a permit?

Yes. Boise requires a permit for an attached patio cover because the new construction transfers loads to the existing residence.

Can an unsigned site plan establish my property boundary?

No. An unsigned drafted plan can show property lines based on supplied records, but it does not establish or certify the legal boundary. An Idaho professional land surveyor may be required.

Can I submit the permit application online?

Yes. Boise provides an online Permitting and Licensing portal for building permits and planning applications.

What building code does Boise use?

Boise currently identifies the 2018 International Residential Code among its adopted residential codes, together with applicable amendments and the 2023 National Electrical Code.

Does a site plan include structural engineering?

No. A site plan shows where the project sits on the property. Foundations, framing, beams, footings, connections and structural calculations are separate documents.

How quickly can USA Site Plans prepare the drawing?

USA Site Plans offers a standard 24-hour turnaround for typical unsigned residential drafting orders when sufficient property records, dimensions and project information are supplied.

Does an unsigned site plan guarantee approval?

No. Approval depends on the property, project, zoning, building code and review by the City of Boise and other responsible authorities.

Related USA Site Plan Guides

Final Thoughts

A clear Boise residential site plan should make the property and proposed home project easy to understand.

The drawing should show property boundaries, existing buildings, proposed construction, setback dimensions, driveways, walkways, easements and other relevant site conditions.

Depending on the project, the permit package may also require architectural plans, structural drawings, erosion-control documents, floodplain information or hillside engineering.

Accurate source information and consistent dimensions can reduce review comments caused by missing features, unclear labels or drawings that do not match the rest of the permit set.

Ready to begin?

Order your Boise residential site plan
.

Official Boise Resources

• 
  City of Boise Homeowner’s Guide to Residential Construction
  
• 
  Residential Addition, Alteration and Accessory Building Checklist
  
• 
  New Residential Submittal Checklist
  
• 
  New Residential Construction Permits
  
• 
  Boise Zoning Code
  
• 
  Boise Current Building Codes
  
• 
  Boise Permitting and Licensing Portal
  
• 
  Boise Hillside New Residential Guide
  

Disclaimer: This article provides general educational information and does not constitute legal, zoning, surveying, architectural, engineering, grading, drainage, floodplain, hillside, historic-preservation, building-code or permit-approval advice. Requirements depend on the property, zoning district, recorded plat, project scope and current instructions from the City of Boise. USA Site Plans provides unsigned drafting services based on supplied property records and project information. An unsigned drafted site plan does not establish legal boundaries or replace a licensed surveyor, architect, engineer or other professional when one is required.