Garages, sheds, and accessory structures

Depending on the age of your house, we may have the permit history.

Checking a house's permit history is important. It helps ensure compliance with building codes. Also, it can reveal issues with renovations or additions. These problems might affect the home's value or future repairs.

Learn how to find the permit history with public records.

The Zoning Code (City Title 33) sets rules and standards for if and where you can build. This includes limits on building size and placement, like maximum coverage and setbacks. These rules will impact how your structure fits on your property.

Call 503-823-7300 and ask to speak with zoning staff to determine your setbacks.

• Understand the zoning requirements for your project
  • Use the Detached Covered Accessory Structure Worksheet
    • Download PDF fileDetached Covered Accessory Structures Worksheet 1.29 MB

Your project must meet all the codes and rules that apply. These include:

• Oregon Residential Specialty Code (ORSC)
• Portland City Codes
  • Title 11 Tree Code
  • Title 24 Building Regulations
  • Title 33 Zoning Code 

Other codes may apply based on the scope of work.

For the full list, visit Codes, rules, and guides.

You will need electrical, plumbing, or mechanical permits.

You can apply for these permits in two ways: individually or as a permit package.

Residential Combination: building and trade permit package

A residential combination permit is one permit. It includes all structural work and trades work like electrical, mechanical, and plumbing. That's one permit to purchase and keep track of.

A combination permit lets you request all inspections using one permit number.

How to purchase a Residential Combination permit package

Submit these trade permit applications along with your building permit application.

• Electrical
• Mechanical
• Plumbing

You will need completed subcontractor forms when applying for the Residential Combination permit.  If not, you will have to apply for trade permits separately from the building permit.

Subcontractors must be registered with the State of Oregon. They must carry the correct licenses associated with their trade.

If zoning allows your structure to be near a property line, you must still follow these rules:

• Increased Fire Protection. If your structure is close to a property line, it requires a higher level of fire protection.
• Three-foot rule. If you build within three feet of a shared property line, your structure needs to be fire-rated. This applies to lines with neighbors, not streets or alleys.
• Additional fire protection. If you have a garage as your accessory structure, and it will attach to or be within three feet of the house:
  • Cover interior walls with ½ inch gypsum board or similar. Apply it to the interior side of exterior walls in this area.
  • If there are openings like doors or windows nearby, they might also need protection.

See our handout on Eaves and Exterior Wall Protection: 

The City requires driveway access to the garage. If you don’t have a driveway, you must put one in.

• Is the driveway within 150 feet of an improved (paved) public right-of-way?
  • If yes, it must be paved.
    • The Zoning Code also includes requirements that may limit the width of a new driveway. For more on paving surfaces, visit Portland City Code, Title 24.45.020.

Transportation will review the project. You will need a separate transportation permit for work in the public right-of-way. 

Learn more about driveway regulations.

For right-of-way requirements, contact the Transportation at 503-823-7002, option 3.

• Plan to use the garage as an accessory dwelling unit (ADU)? Visit the ADU permit page.
• Explore other living space conversion options.

Sometimes, you can use cargo containers as accessory structures. Cargo containers used in this way must meet all the requirements of the codes.

Read more in the cargo container code guide: Building Code Guide 96-11: Cargo Containers

Some properties have existing septic tanks or cesspools that may or may not be used.

What you need to do

• Within 10 feet of new footings and foundations
  • Locate and decommission abandoned septic tanks.
    • Required for additions if the house was not connected to the sewer when built.
• Got a septic system? Please contact septic@portlandoregon.gov

Contractors

Contractors must have a license to work in Oregon. The Oregon Construction Contractors Board (CCB) issues licenses to contractors. The CCB website has good tips on searching for a licensed contractor. Plumbing and electrical contractors have additional license requirements. The permit application must list the license number.

Homeowner

If you are a homeowner doing the work yourself, then you can sign the trade permit applications. You can do the electrical work only if you own and occupy the home and are not selling or renting within six months. If you're doing the work yourself, you must fill out and submit this form:

Permitting fees are based on:

• Type of permit
• Work proposed
• Cost of construction labor and materials (valuation)
• Staff that needs to review the work

Learn more about permit fees. 

Scale site plans to most appropriate scale, e.g. 1”=10’ or 1/4”=1’.

• Property lines, with dimensions
• Total area (in square feet) of the lot
• Adjacent streets and any easements
• Property address and R number
• North arrow (arrow pointing to the north direction)
• Grade elevations
  • at property corners
  • corners of structure(s) with reference elevation datum
  • driveway, at the top of the curb and at the gutter
• Distance between buildings and property lines
• Dimensions and area (in square feet) of any
  • existing or proposed buildings
  • proposed paving
• Location of sewer and water lines and method of stormwater disposal
• Major geographical features (e.g. flood plain, natural drainage courses with elevation and centerline)
• Location of existing septic tanks, cesspools and drainfields, if applicable
• Driveways, curb cuts and onsite parking spaces (existing and proposed)

Get the sample site plan and learn how to find these requirements in Drawing a site plan.

Scale of plans to be ¼”=1’ and details scaled to ½”=1’.

Plans must show wall thickness. Single line drawings are not acceptable.

• Fully dimensioned floor plans, showing:
  • Walls (with wall legend)
    • demolished walls
    • existing walls to remain
    • proposed walls
  • Windows (for each floor affected)
    • size
    • sill height
    • method of operation
    • safety glazing
    • window wells (where required)
  • Doors (for each floor affected)
    • size
    • swing direction
  • Label for use of each room
  • Plumbing fixture layout
  • Gas/oil furnace and water heater location
  • Electrical light fixtures
  • Exhaust fans
  • Smoke and carbon monoxide detectors
• Exterior building elevations (side views of each side)
  • Labels for new and existing areas
• Dimensioned building section(s), showing:
  • Typical wall, floor, ceiling, roof, and foundation construction
  • Framing members, insulation, and blocking
• Stair details with dimensions for
  • Risers
  • Treads
  • Headroom clearance
  • Guardrail and handrails
• Details of all non-typical construction

Find samples and more information in Building permit plans.

Scale of plans to be ¼”=1’ and details scaled to ½”=1’.

• Gravity load analysis
  • Show load transfer through added or altered areas, including:
    • Roof framing plan showing existing and new members. Include:
      • beams and rafters (with lumber size, spacing and span)
      • supporting walls and posts
    • Floor framing plan(s) showing existing and new members. Include:
      • beams and joists (with lumber size, spacing and span)
      • supporting walls and posts
    • Foundation plan showing how new loads are supported. Include:
      • ventilation
      • underfloor access
      • hold-downs
    • Calculations for the framing members
• Lateral load analysis for resistance to wind and seismic forces.
  • Show either prescriptive or engineered method, including:
    • Braced panels and braced wall lines for prescriptive method (per ORSC R602.10):
      • Locate, dimension, and identify type

Your project needs to follow all structural rules in the building code. The structural drawings must show how the structure will resist gravity and side loads. Examples include stresses like wind and earthquakes.

Visit Structural Design Requirements for One and Two-Family Residential Structures.

Find samples and more information in Building permit plans.