Do you need a site plan for a carport permit? In many cities and counties, the answer is yes. A carport changes how part of the property is used and covered, so permit reviewers may need to check its location, size, height, setbacks, driveway access, lot coverage and relationship to easements or utilities.

A carport permit site plan, sometimes called a plot plan, is a scaled drawing of the property viewed from above. It shows the proposed carport in relation to the house, property boundaries, driveway, street, existing structures and other important site features.

Permit rules vary by jurisdiction. Some cities require zoning and building permits for every carport. Others provide limited building-permit exemptions for small detached or attached carports, but zoning, setback and lot-coverage rules can still apply. [1][2][3][4]

What Is a Carport?

A carport is a roofed structure designed to shelter vehicles. Unlike a garage, it is normally open on one or more sides.

A residential carport may be:

• Attached to the house
• Freestanding beside the house
• Located behind the house
• Connected to an existing driveway
• Accessed from a rear alley
• Built from wood, steel, aluminum or another approved system
• Constructed from custom plans or a prefabricated kit

The fact that a carport has open sides does not automatically make it permit-exempt. The roof, posts, foundations and wind loads still create structural and zoning considerations.

When Is a Site Plan Required for a Carport?

A site plan is commonly required when the carport needs building, zoning or residential-lot approval.

You are especially likely to need one when the proposed carport:

• Is attached to the house
• Exceeds the locally exempt area or height
• Is close to a property line
• Will be built in the front or side yard
• Uses an existing driveway or alley
• Requires a new driveway or curb cut
• Changes the property’s building or lot coverage
• Is near a utility or drainage easement
• Includes electricity, lighting or solar panels
• Is located in a floodplain or environmentally sensitive area
• Will be enclosed now or in the future
• Is replacing an existing garage or carport

Minneapolis describes a construction site plan as a drawing showing the property lines, existing structures and the location of a proposed garage or other planned improvement. Its published checklist includes adjacent streets, easements, building dimensions, setbacks, distances between structures, a north arrow and drawing scale. [5]

Portland also requires permit plans to be drawn to scale. Its site-plan guidance says the plan should show the entire property, the footprint of all structures and the driveway. [6]

Does Every Carport Need a Building Permit?

No single national rule applies. Current official requirements demonstrate how much the answer can differ from one location to another.

• Denver: All carports require both a zoning permit and a building permit. Trade permits may also be needed when lighting, heating, water or other systems are added. [1]
• Portland: A detached, one-story carport of 200 square feet or less may be exempt from a building permit. Portland may also allow an attached carport of 200 square feet or less to avoid a building permit when it is at least three feet from the property line. Zoning approval is still required when no building permit is required. [2]
• Austin: Certain one-story detached accessory structures may be exempt when they are no more than 200 square feet and 15 feet high, contain no plumbing, create no dwelling and are outside a flood-hazard area. The owner should confirm whether the proposed carport satisfies the exemption. [3]
• Fairfax County: Detached carports are listed among the structures handled through the residential New Building permit process. [7]
• Seattle: Certain detached one-story accessory structures with a projected roof area under 120 square feet and a slab-on-ground foundation may be exempt, but exempt projects must still satisfy development standards and may not qualify on environmentally critical sites. [4]

These examples are not interchangeable. A size allowed without a building permit in one city may require full building and zoning approval somewhere else.

Attached Carport vs Detached Carport

Whether the carport is attached or detached can change the approval and construction requirements.

Attached Carport

An attached carport connects structurally to the house or another building.

The application may need to address:

• Connection to the existing wall or roof
• Ledger, beam or rafter attachment
• Flashing and weather protection
• New loads placed on the existing building
• Fire separation near windows and doors
• Roof drainage at the connection point
• Changes to the existing building elevation

The site plan should show where the carport joins the house and how the combined footprint relates to every property boundary.

Detached Carport

A detached carport stands separately and is normally treated as an accessory structure.

Review may focus on:

• Side and rear-yard location
• Distance from the house
• Distance from property lines
• Driveway and alley access
• Height and roof design
• Lot coverage
• Utility and drainage easements
• Wind resistance and anchoring

Portland’s current determination specifically treats detached carports as accessory structures when applying its limited 200-square-foot building-permit exemption. [2]

Site Plan vs Construction Plans

A site plan explains where the carport goes. Construction plans explain how the carport will be built.

The site plan normally shows:

• Property boundaries
• Existing house and structures
• Proposed carport footprint
• Carport dimensions
• Boundary setbacks
• Driveway and vehicle access
• Easements and utilities
• Street, alley and north arrow

Construction drawings may show:

• Footings and anchors
• Posts and columns
• Beams and rafters
• Roof framing
• Roof pitch and covering
• Connection to the house
• Bracing and lateral resistance
• Fasteners and structural details

Portland’s permit guidance separates the site plan from floor plans, elevations and structural pages. All required plans must be clear and drawn to scale. [6]

What Should a Site Plan for a Carport Permit Show?

The exact checklist depends on the local permitting authority, but the following information is commonly useful.

Property Boundaries and Lot Dimensions

Show the complete legal outline of the property.

Include:

• Front property line
• Side property lines
• Rear property line
• Length of each boundary
• Lot width and depth
• Irregular or angled boundaries
• Property address

The property lines are the reference points used to measure the carport setbacks.

Do not automatically assume that a fence, hedge or row of trees marks the exact legal boundary. A survey may be needed when the carport will sit close to a property line.

Street, Alley and Right-of-Way

Show and label every street or alley adjoining the lot.

The plan may include:

• Street name
• Public or private alley
• Sidewalk
• Curb or kerb line
• Public right-of-way
• Side street on a corner lot
• Existing driveway connection

This helps reviewers understand how vehicles will reach the carport and whether any public-right-of-way work is proposed.

Existing House

Show the complete footprint of the existing dwelling.

Include relevant:

• Exterior walls
• Roof outline
• Windows and doors near the carport
• Existing garage
• Porches, decks and additions
• Connection point for an attached carport

The drawing should make it easy to understand whether the carport is attached, freestanding or connected by a covered walkway.

Other Existing Structures

Show other structures and improvements that may affect the proposed location.

These may include:

• Garage or shed
• Existing carport
• Deck or patio
• Swimming pool
• Accessory dwelling unit
• Retaining walls
• Fences and gates
• Mechanical equipment
• Water tanks

Leaving existing structures off the plan can produce inaccurate setback, parking and lot-coverage calculations.

Proposed Carport Location

Clearly identify the proposed work using a label such as:

Proposed Carport

Use a bold outline, hatching or a different line type so the carport can be distinguished from the existing house and structures.

If an existing carport will be removed or replaced, show:

• Existing carport to be demolished
• Existing footprint
• Proposed new footprint
• Posts or slab proposed to remain

Carport Length, Width and Covered Area

Show the outside dimensions of the proposed roofed structure.

Include:

• Overall length
• Overall width
• Total covered area
• Roof overhangs
• Gutters
• Storage areas or attached enclosures

A useful note may read:

Proposed Carport: 20 ft × 24 ft — Covered Area: 480 sq. ft.

Portland measures its 200-square-foot carport exemption using the usable area under the roof at the drip line rather than only the area between the posts. [2]

Front, Side and Rear Setbacks

Show the shortest measured distance from the carport to every nearby property line.

Dimension the:

• Front setback
• Left-side setback
• Right-side setback
• Rear setback
• Setback from a side street on a corner lot
• Distance from the roof edge or drip line where required

Use the local measurement rules. Some jurisdictions measure a setback from the outer roof edge rather than from the supporting posts.

Portland’s carport guidance says zoning setbacks and building-coverage limitations apply even where the carport qualifies for a building-permit exemption. It also states that carports must generally remain at least 18 feet from a street property line. [2]

Those are Portland-specific rules and should not be applied automatically in another city.

Distance From the House and Other Structures

For a detached carport, show the distance to the:

• Existing house
• Garage
• Shed
• Accessory dwelling unit
• Pool or pool barrier
• Retaining wall

The separation can affect fire-resistance requirements, roof projections, drainage and access between structures.

Carport Posts and Roof Outline

The site plan may show the roof footprint and general post locations.

Identify:

• Roof edge
• Post or column locations
• Open sides
• Any enclosed wall
• Attached storage room
• Connection to the house

Detailed footing, post, beam and roof-framing information normally belongs on the structural drawings.

Building Height and Roof Design

Show or note the proposed carport height.

Relevant information may include:

• Post height
• Maximum roof height
• Average roof height
• Roof pitch
• Flat, gable, hip or skillion roof
• Height at the property-line side

Height can affect zoning approval, setbacks and whether the project qualifies for a small-structure exemption.

Austin’s detached accessory-structure exemption, for example, is limited to qualifying structures no more than 15 feet high. [3]

Existing and Proposed Driveway

Show the vehicle-access route from the road or alley to the carport.

The plan may identify:

• Existing driveway
• Proposed driveway extension
• New driveway
• Driveway width
• Parking pad
• Connection to the street or alley
• Existing or proposed curb cut
• Driveway material

Portland’s site-plan requirements specifically call for the entire property, all structure footprints and the driveway to be shown. [6]

Vehicle Access and Parking Layout

Show how a vehicle will enter, park and leave.

Include where relevant:

• Parking-space outline
• Vehicle direction
• Turning area
• Clear space beside posts
• Access to both carport bays
• Clearance from gates and fences

The carport should line up with the driveway. A beautifully drafted roof over a parking space no car can reach is, technically, just an expensive outdoor umbrella.

Driveway or Curb-Cut Changes

A separate permit may be required when the carport project includes:

• A new curb cut
• A widened driveway
• A second driveway entrance
• Changes to a sidewalk
• Work in the public right-of-way
• Access from a state-controlled road

Denver advises that projects involving a new or modified driveway connection or curb cut may receive transportation review and may require improvements to adjacent public infrastructure. [1]

See our guide on garage permit site plans for related driveway and accessory-building considerations.

Easements

Show every known easement affecting the proposed carport area.

Common examples include:

• Utility easement
• Drainage easement
• Sewer easement
• Access easement
• Stormwater easement
• Shared-driveway easement

Label the easement width and purpose.

Do not place posts, foundations, roof overhangs or enclosed storage areas inside an easement without confirming that construction is allowed.

Utilities and Services

Show known utility features near the carport.

These may include:

• Sewer line
• Water service
• Gas line
• Underground electrical service
• Overhead power line
• Utility pole
• Stormwater pipe
• Water, gas or electrical meter

Before footing excavation begins, underground utilities should be located through the appropriate local utility-location service.

Electrical Work and Lighting

A separate electrical permit may be required when the carport includes:

• Ceiling lights
• Security lighting
• Power outlets
• Electric vehicle charging
• New electrical service
• Solar panels

Denver states that trade permits may be required when light, heat, air conditioning or water is added to a covered structure. [1]

Show the service route or equipment location when requested by the permitting authority.

Solar Carports

A carport supporting solar panels may need additional structural and electrical review.

The application may require:

• Solar-panel layout
• Panel weight and mounting details
• Wind-load calculations
• Electrical single-line diagram
• Equipment and disconnect locations
• Clearance around utilities

The site plan should show the carport footprint, while the structural and electrical plans provide the system details.

Drainage and Stormwater

A carport roof creates additional runoff even when its sides are open.

The site plan may show:

• Roof-fall direction
• Gutters
• Downspouts
• Stormwater connection
• Surface-flow arrows
• Drainage swales
• Stormwater pits
• Lawful discharge point

Water should not be directed toward the house, neighbouring property or an area where it could cause erosion or ponding.

Denver notes that projects near sewer lines or in floodplains may require sewer-use-and-drainage approval. [1]

Lot Coverage and Impervious Area

The carport roof and parking surface may affect lot coverage, building coverage or impervious-area limits.

Where required, show:

• Total lot area
• Existing house footprint
• Existing garage, shed and covered structures
• Proposed carport area
• Driveway and parking area
• Patios and other paved surfaces
• Total proposed coverage

Portland confirms that zoning building-coverage limitations apply to carports, including those that do not require a building permit. [2]

Existing and Proposed Ground Levels

Show site levels where the property slopes or the carport requires grading.

The plan may include:

• Existing contours
• Natural ground levels
• Proposed slab or parking level
• Driveway levels
• Direction of fall
• Areas of excavation or fill

Additional elevations or sections may be required for a steep site.

Retaining Walls and Earthwork

Show retaining walls or grading needed to create the carport and parking pad.

Include:

• Wall location
• Wall height
• Cut and fill areas
• Distance from the carport
• Distance from property lines
• Drainage behind the wall

Retaining walls may need separate permits or structural engineering depending on their design and location.

Trees and Landscaping

Show significant trees where the carport, driveway or construction access may affect them.

The plan may identify:

• Tree-trunk locations
• Trees to remain
• Trees proposed for removal
• Street trees near a new driveway
• Tree-protection areas
• Landscaping removed for parking access

Denver directs applicants to contact the city forester when a project may affect public-right-of-way tree roots or canopy. [1]

Septic Systems and Private Wells

Properties not connected to public sewer or water may need to show:

• Septic tank
• Drain field
• Reserve disposal area
• Private well
• Required separation distances

The carport, posts and driveway should not damage the system or block maintenance access.

Floodplain and Environmentally Sensitive Areas

Special review may apply when the property is in a:

• Floodplain
• Wetland area
• Steep-slope area
• Coastal zone
• Environmentally critical area
• Protected drainage corridor

Austin excludes detached accessory structures inside flood-hazard areas from its small-structure building-permit exemption. Seattle also limits its common accessory-building exemption on environmentally critical sites. [3][4]

North Arrow, Scale and Drawing Information

The plan should include:

• North arrow
• Recognized drawing scale
• Property address
• Drawing title
• Date prepared
• Revision number

Possible residential site-plan scales include:

• 1 inch = 10 feet
• 1 inch = 20 feet
• 1/8 inch = 1 foot for a compact lot

Portland’s minimum accepted site-plan scale is one inch equals ten feet, and the entire lot must be shown. Minneapolis also lists a north arrow and drawing scale among its standard site-plan details. [5][6]

What Other Drawings May Be Required?

A carport site plan is normally only one part of the permit package.

The permitting authority may also request:

• Foundation or footing plan
• Roof-framing plan
• Front, side and rear elevations
• Building sections
• Post and beam details
• Attachment details
• Bracing and anchoring information
• Structural calculations
• Manufacturer specifications
• Electrical plan
• Drainage or grading plan

The site plan demonstrates the location. The other drawings demonstrate that the structure can safely resist gravity, wind, snow and other applicable loads.

Prefabricated and Metal Carport Kits

Buying a manufactured carport kit does not automatically remove the need for permits.

Permit reviewers may request:

• Manufacturer drawings
• Engineering certification
• Wind and snow-load ratings
• Foundation and anchoring details
• Post spacing
• Roof dimensions
• Installation instructions

The site plan still needs to show where the kit will be installed and whether its dimensions, setbacks and access comply.

Replacing an Existing Carport

Replacing an old carport does not automatically mean that permits are unnecessary.

The replacement may differ in:

• Length or width
• Roof height
• Post location
• Roof material
• Attachment to the house
• Number of enclosed sides
• Driveway and parking layout

The old carport may also have been built under earlier zoning rules or without a permit.

A replacement-carport site plan should distinguish:

• Existing structure to be removed
• Existing slab to remain
• Proposed new roof and posts
• Existing and proposed dimensions
• Current boundary setbacks

Enclosing an Existing Carport

Enclosing a carport to create a garage, room or living area is normally more complex than installing an open carport.

The conversion may require:

• Building permit
• Zoning review
• Site plan
• Floor plans and elevations
• Foundation verification
• Wall framing and insulation
• Fire separation
• Windows and emergency egress
• Replacement parking where required
• Electrical, plumbing or mechanical permits

A slab designed only for vehicle parking may not meet the requirements for enclosed or habitable space.

Do You Need a Survey?

Not every carport application requires a new boundary survey. An existing property survey, house-location plan or recorded plat may provide a usable base.

A survey may be needed when:

• The carport is close to a property line
• Property corners cannot be located
• The fence may not follow the legal boundary
• An easement location is uncertain
• The lot is irregular
• The permitting authority specifically requests one
• The property is affected by flood elevations

A drafted permit site plan is not a boundary survey and should not be represented as one.

Common Carport Site Plan Mistakes

Applications are often delayed because important property or project information is missing.

Common mistakes include:

• Property lines are not shown
• The carport is not clearly labelled as proposed
• Roof dimensions are missing
• The area is measured only between the posts
• Boundary setbacks are omitted
• Roof overhangs are ignored
• The distance to the house is missing
• Attached and detached construction is unclear
• The driveway does not align with the parking area
• Vehicle access is not shown
• Existing garages, sheds or decks are omitted
• Easements are ignored
• Utilities are not shown
• Lot coverage is missing where required
• Roof drainage is not addressed
• The proposed height is missing
• The drawing is not to scale
• There is no north arrow
• The site plan conflicts with the manufacturer or structural drawings

What Information Is Needed to Prepare the Site Plan?

Collect as much of the following information as possible:

• Property address
• Carport length and width
• Roof height and pitch
• Attached or detached design
• Preferred carport location
• Distances to nearby property lines
• Post locations if known
• Driveway and parking layout
• Street or alley access
• Photos of the property
• Rough sketch with measurements
• Existing survey or plot plan
• Recorded plat if available
• Manufacturer or contractor drawings
• Known easements
• Utility and drainage information
• Site levels or slope information
• Permit reviewer comments

Carport Permit Site Plan Checklist

Does a Site Plan Guarantee Carport Permit Approval?

No. A clear site plan gives reviewers the information needed to understand the proposed location, but approval also depends on zoning, structural design, adopted building codes and property conditions.

The project may also require:

• Structural or manufacturer drawings
• Licensed boundary survey
• Zoning approval
• Driveway or curb-cut permit
• Drainage or grading plan
• Electrical permit
• Floodplain or environmental review
• Historic-district approval
• Tree-removal approval
• HOA or architectural-review approval

Need a Site Plan for a Carport Permit?

Site Plan Pros prepares clear residential site plans for homeowners, contractors and permit applications.

Your carport site plan can show:

• Property boundaries
• Existing house and structures
• Proposed carport location
• Carport dimensions
• Boundary setbacks
• Driveway and vehicle access
• Easements and utilities
• Other relevant property details

You may also find our guides on deck permit site plans, garage permit site plans, permit site plan checklists and site plans versus surveys helpful.

Confirm the local permit threshold, setbacks, height limits and driveway requirements before purchasing a carport kit or beginning construction.

Sources

1. City and County of Denver — Residential Decks, Porches, Patios, Pergolas and Carports
2. City of Portland — Building Official Determination 21-01: Carports Under 200 Square Feet
3. City of Austin — Work Exempt From Building Permits
4. Seattle Department of Construction and Inspections — Do You Need a Permit?
5. City of Minneapolis — Construction Site Plans
6. City of Portland — What You Need to Apply for a Permit
7. Fairfax County — Residential Building Permit Library
8. City of Austin — Residential Plan Review
9. City of Portland — Common Residential Home Projects