Accessory Dwelling Units in Florence

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The City of Florence allows Accessory Dwelling Units (ADUs) in all residential zoning district on properties with existing primary single-unit detached dwellings.  Additional details are available in Florence City Code (FCC) Title 10, Chapter 10, Section 6, which regulates ADUs (starts on bottom of page 5).  ADUs are required to meet siting standards such as minimum setbacks, maximum lot coverage, and architectural standards for the underlying zoning district.  If you are interested in building an ADU on your property please prepare a site plan with all existing and proposed structures and City Building or Planning staff will be able to assist you in determining if minimum requirements can be met and guide next steps.

This is intended to be a brief overview of frequently asked questions on the ADU topic and does not cover all scenarios.  For more information please contact the planning department at (541) 997-8237 or planningdepartment@ci.florence.or.us or contact the Building Department ar (541) 997-2141 or florencepermits@ci.florence.or.us

Frequently Asked Questions

What are Accessory Dwelling Units?

Accessory Dwelling Units (ADUs) are defined in FCC 10-2-13 as an additional dwelling which is accessory to a primary dwelling on a property.  ADUs may be attached, detached, or interior to an existing primary dwelling.

  • Attached: ADU and the primary dwelling share a common wall, roof, or foundation.
  • Detached: ADU is on the same property as the primary dwelling, but is not attached.
  • Interior: An ADU that is constructed within the structure of the primary dwelling.
    • Such as a conversion of a bedroom into a separate dwelling unit.
Category: Accessory Dwelling Units
How large of an Accessory Dwelling Unit can I build?

Accessory Dwelling Units may be a minimum of 201 sq. ft. and a maximum of 1,000 sq. ft. or 75%  of the primary dwellings size, whichever is less.

Owners of small primary dwellings (500 square feet or less) can construct or place an ADU of equal size.

For example:

  • The owner of a 1,200 – sq. ft. home could build up to a 900 square foot ADU
    • 75% of 1,200 sq. ft. = 900 sq. ft.
  • The Owner of an 1,800 sq. ft. home could build up to a 1,000 square foot ADU.
    • 75% of 1,800 sq. ft. = 1350 and the maximum sq. ft. of an ADU is 1,000 sq. ft.
  • The owner of a 480 sq. ft. home could place an ADU up to 480 sq. ft. in area.
Category: Accessory Dwelling Units
Can I use a tiny home on a trailer as an ADU?

Yes, if the structure is made permanent through the payment of Systems Development Charges (when required) and it meets all the requirements of state Building and Fire Codes and architectural standards for the underlying zoning district (FCC 10-10).

ADUs built on an axel frame may be considered a permanent dwelling through the removal of tongue and running gear, addition of blocking, and the addition of skirting.

Please consult with the Building Official for more information regarding these structures.

Category: Accessory Dwelling Units
Can I operate a short-term rental out of my ADU?

No. Florence City Code FCC 10-10-6-C (pg. 7) prohibits renting an ADU as a short-term rental (stay less than 30 days).  ADUs are intended to encourage a variety of housing types to meet long-term housing needs in the City.

Any person operating a short-term rental within Florence City limits is required to obtain a City of Florence Business license. For more information, please visit this LINK. 

Category: Accessory Dwelling Units

Supporting Documents

PDF icon Accessory Dwelling Unit Fact Sheet - Updated February 2022 (314 KB)

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