Create an Accessory Dwelling Unit on Your Property

If you are looking for long-term rental income or want to house family and friends, you can create an accessory dwelling unit (ADU) on property you own. ADUs are an additional, smaller dwelling on the same property as your single-family home. ADUs cannot be used for short-term rentals. Unlike a guest house, an ADU must be an independent dwelling unit having both a kitchen and a bath. Tenants can live in an ADU permanently. Tenants who are renting must be renting for at least 30 days.

Examples include:

  • A “mother-in-law” cottage
  • A basement apartment
  • An apartment over the garage

Where you can create an ADU

Accessory dwelling units are allowed as a special use in the following zones:

  • Residential Agriculture (RA)
  • Single-family Residential (RS)
  • Duplex Residential (RD)
  • Multiple Family Residential 1 (RM1)
  • Multiple Family Residential 2 (RM2)
  • Multiple Family High-Rise Residential (RH)
  • Commercial Office (CO)
  • Retail Commercial (CR)
  • General Commercial (CG)
  • Central Business District (CB)
  • Industrial Commercial (IC)
  • Industrial Park (IP)
  • General Industrial (IG)
  • Neighborhood Center Mixed-Use (NCMU)
  • Mixed Use-I (MU-I)
  • Mixed Use-II (MU-II)

Characteristics of an ADU

Some of the defining traits of an accessory dwelling unit include:

  • Only one ADU per lot
  • No off-street parking spaces are required for ADUs
  • Square footage is limited to 900 square feet or 75% of the main house, whichever is less
  • Height is limited to 25 feet tall for detached ADUs
  • An ADU must include both a bathroom and a kitchen
  • Does not have a direct interior connection to the main house

You can review all the specifications in Salem Revised Code 700.007.

Process for getting ADU approval

ADU is considered a special use, so no land use application process is required as long as you can meet the special use standards. You do need a building permit. Off-street parking spaces are not required for ADUs.

System Development Charges (SDCs)

Public Works staff has formed a work group to review and update the methodology used to establish SDCs in Salem. The group is expected to review how SDCs should be charged for ADUs. The group's work is expected to be complete later this year and will result in a recommendation to City Council. Prior to that work being complete, the City will charge SDCs for an ADU based on current rules:

  • Parks (same as a multifamily unit): $3,016.68
  • Transportation (same as a multifamily unit): $1,371.96
  • Stormwater: Does not apply
  • Water and Sewer: Does not apply unless water meter size is changed. You will be required to complete a water meter sizing worksheet when you apply for your building permits.

Additional information about creating and working with ADUs

Background on ADUs

The City started to consider allowing accessory dwelling units in Salem in 2016 as a first step of a multi-year project to address Salem’s projected deficit of land for multifamily housing. The projected 207-acre deficit was identified in the Salem Housing Needs Analysis. That analysis examined if there was enough land in Salem’s portion of the urban growth boundary to meet housing needs over the next 20 years.

Project documents:

​Councilor Steve McCoid on ADUs


Contact us

Permit Application Center Planning Desk
8:00 a.m.–5:00 p.m.
555 Liberty ST SE RM 320
Salem OR 97301
Mailing address:
555 Liberty ST SE RM 305
Salem OR 97301
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