Accessory Dwelling Unit

What is an ADU?

ADU is short for Accessory Dwelling Unit.  It can be accessory to detached single-family homes, townhouses, manufactured homes and duplex dwellings on their own lot.

Examples of ADU’s

Jump to your town’s ADU rules: MedfordPhoenixTalentAshland Central PointJackson County

If you are a professional homebuilder, see this set of ideas.

Why ADUs are important for you and your community

  • Creates more housing density at lower costs within the Urban Growth Boundaries that maintain our wide open spaces for ag and wildlife.  
  • Serves people and places according to AARP by creating attainable housing for elders and people starting out.
  • Supports aging in place, generational wealth building, and housing for extended family or friends.
  • Adds affordable “missing middle” housing options in a moment of critical shortage/ opportunity.  Missing middle is everything from ADUs to 8 unit complexes. 
  • Generates income – what does a 1 bedroom unit rent for in your area?
  • Increases property values 25% to 34%. A 2012  study from Portland.
  • Accelerates mortgage payoff at a time when 24% of Oregon homeowners are mortgage burdened and of that 9% are severely cost burdened- Oregon Center for Public Policy
  • Reduces the need for cars and increases walking, biking, and transit use.

How an ADU could work for you

  • ADUs are extremely valuable when it’s time to sell your home. 
    • Studies show that ADUs can increase property values and make homes more desirable to potential buyers, especially those interested in aging-in-place.
  • Estimate your gains using this handy calculator.  Scroll down the calculator to adjust assumptions. Or try this calculator.

Here’s Derek Sherrell, local ADU developer who offers a lot of great advice and encouragement to anyone interested in ADUs. 

See more tips from Derek, That ADU Guy, on YouTube and on his website.

Pre-approved ADU Plans

Here’s Carlos Delgado, the architect who designed the ADU plans pre approved in the city of Medford talking about his approach to ADUs.

When ADUs might not work

  • Zoning  restrictions – most single family lots can now include an ADU
  • Not enough space on your lot – buildable area of your lot, set backs, etc.
  • Access to utilities is expensive – is there enough slope for the sewer line?
  • Upfront costs of planning and permits
  • Financing ADU’s can be tricky – check with your banker
  • The form of your existing house  may not make an attached ADU easy – attached ADU example

Check with your local community development staff before you give up on the ADU idea. More info below

How to get started

Here’s Kristen Maze, Director of Community Development at the City of Talent helping you think about preparing to apply for permits to build an ADU.

Trying to Make the Complex Simpler

This process is NOT simple. We are trying to help you get started, but know that there are many options and potential roadblocks along the way.  But, as Derek says, the hard work is definitely worth it!

Lots of good materials on these websites:

A Few Key Details About ADUs In Your Area

This is only a few key pieces of a much larger puzzle.  Check with your local planning department, their contact information is at the top of this table. On your phone, click on the phone number to dial it.

Click to jump to your town: MedfordPhoenixTalentCentral PointJackson County

Ashland

Planning department contact information

541-774-6907

ADUs are allowed in zones

R-1, R-1-3.5, RR, WR, R-2, R-3, NN, NM

Setbacks and coverage ratios

Set back and coverage ratios vary for different zones. Find the requirements for your zone here.

Other rules

Just a start here, look at more info links for the complete picture

Off-street parking is NOT required

Accessory Residential Units (ARU) and in the Single-Family Residential Zones (R-1-5/R-1-7.5 & R-1-10) ARUs require a Conditional Use Permit.

More info here

Link to building permits

Permits, Forms, & Fees

Central Point

Planning department contact information

541-664-3321

stephanie.holtey@centralpointoregon.gov

ADUs are allowed in zones

R-L, R-1, R-2
LMR, MMR, HM

Setbacks and coverage ratios

Rear Yard Setback: 5 ft
800 sq ft or 50% of the gross floor area of the primary dwelling, whichever is less

Other rules

– just a start here, look at more info links for the complete picture

Off street parking is NOT required.
Separate utility connections are not required

More info here

Link to building permits

Permits

Medford

Planning department contact information

541-774-2380

planning@cityofmedford.org

ADUs are allowed in zones

MFR-30, MFR-20, MFR-15, SFR-10, SFR-6, SFR-4, SFR-2

Setbacks and coverage ratios

Up to 75% of the primary dwelling’s Gross Habitable Floor Area (GHFA)
Detached ADUs cannot be larger than 900 sq. ft.; attached ADUs converted from existing space in the primary home cannot be larger than 50% of the primary dwelling

Other rules

– just a start here, look at more info links for the complete picture

Off street parking is NOT required

More Info here

Link to building permits

Applying for a permit
ADU Fee Waiver

Phoenix

Planning department contact information

541-774-6907

ADUs are allowed in zones

R-1

Setbacks and coverage ratios

Maximum lot coverage 40%
Minimum lot size 6,000sqft

Other rules

– just a start here, look at more info links for the complete picture

Off street parking is NOT required

More info here

Link to building permits

Building permit information here

Talent

Planning department contact information

541-774-6907

ADUs are allowed in zones

RLD, RMD, RHD, RMH, CN

Setbacks and coverage ratios

Not to exceed 800 square feet of floor area, or 75 percent of the primary dwelling’s floor area, whichever is smaller.

Other rules

– just a start here, look at more info links for the complete picture

Off street parking is NOT required
More info here

Link to building permits

Permits

Jackson County

Planning department contact information

541-774-6907

ADUs are allowed in zones

Unlikely outside the UGB, White City allows ADUs.

Rural areas are unlikely to allow ADUs. That is under review in the state wildfire risk map that is to be completed in Fall 2022.

Depends on your zoning because the County considers an ADU a separate dwelling on the lot.

See question 2 in their FAQs

Setbacks and coverage ratios

Depends on your zoning.

Other rules

Consult with planners at the County.

Link to building permits

Checklist

Permits

Fees

How to finance your ADU construction

  • Local banks you currently work with – equity line of credit, cash out refinance, etc.
  • Craft3 ADU finance program
  • In Portland, some developers who lease your land and build an ADU for you
  • There is a lot of useful data around cost assumptions and financing options in this document from Santa Cruz County in California.  Of course, our fees are different, but many of the construction cost estimates, financing options, etc. are still useful.

Oregon State ADU Code

Oregon Statue on Accessory Dwelling Units in Rural Residential Areas

ADUs are an important way to fill in the missing middle in our housing supply.

A fun tiny house village in Portland. h/t buildinganadu.com

What Home Builders Can Do to Simplify Later ADU Development

Professional home builders can make ADU development much easier by planning ahead. This video offers a few good ideas.

One creative idea for affordable homes with ADUs is for builders to build the ADU first and sell the large lot with its approved larger home site left for future development.  This allows buyers to get started on homeownership more easily while they can look forward to building their larger home once they have built equity in their starter home.

Other Ways to Encourage Missing Middle Development

Posted in Housing Working Group, Projects, Rebuilding.

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  1. Pingback: ADU Resources in Jackson County courtesy of R3V – That ADU Guy

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