Portland (Oregon) ADU taxes

13 Replies

@Andre M. Technically the City is not allowed to reassess your entire house if you build an ADU. It does happen though and it just happened to a friend of ours who just was notified that the taxes were going up by $12k because he added an ADU. That's a ridiculous increase and was a result of the house getting reassessed. He and other landlords have a strong cases to fight it, but it's never fun to tangle with the city. It mainly just comes down to you having to waste precious time to appeal.

I've also been considering buying a single family property here in Portland, building an ADU to live in myself, and then renting out the main property. Came across this article which outlines the progression of the ADU tax implications over the past couple of years. Looks like the county briefly implemented some harsh tax regulations but then changed course shortly there after due to the outcry from ADU owners. If anyone has other helpful information on the ADU tax law, I'd love to hear more.

I'm hoping to get a better grasp on the permitting fees, etc. associated with building a detached ADU. If anyone has experience with that process or helpful links, let me know.


I would be curious too. I know the city is waiving $10k+ worth of fees right now to encourage infill, but I haven't heard anything one way or another about the taxes over time. And what's the difference if you are converting a garage into an ADU versus breaking new ground? If anyone has experience with that, I'd be curious to know. If not, can always call the city.

@Andre M. @Mike Biewer ......@Neal Collins  @Dar Fornelli  are correct... They use to not reassess the whole house than the county came in strong and there was a back lash.. now they are readjusting that but they have not come out with anything I have seen recent.. I have done about 20 adus and some people get reassess heavily because they were really low and never have been adjusted than some we minimal. 

I would go down and talk to the tax accessor or call to get some feedback is my recommendation to all adu clients. 

@Derrick Aragon Good advice. What do you mean by clients?

@Mike Biewer I am GC and we build ADUs, we have done about 20 of them.. Clients = people I have built or people looking to build adus. 

@Derrick Aragon Copy. I'm looking to convert a 450 sq ft garage on my property to an ADU, but haven't gotten deep into the financials yet. It's pretty great because the house is on a corner lot with the garage facade facing a totally different street. When we purchased we brought out an ADU planner, to make sure it was doable, but haven't gone much further. I'm about to engage and architect, but, as you can see in this thread, I'm wondering what will happen to my taxes once I refinance after building it. Plus, the garage is right on the property line, so I'm not sure if that's legit or not. Lots to look into yet.

@Mike Biewer I have done 3 of those, I am actually doing one right now... 

Super easy, probably around $70k, and I would work with me so you don't spend too much on architect... 

I save people tens of thousands of dollars on every project. 

There is no other investment in regards to buying rental properties that can compare. we can walk through the numbers if we choose to work with eachother.. 

@Derrick Aragon

Sweet. I'd be interested in talking more. I'm real interested in seeing the project you are in the middle of. Any chance I could stop by?


This post has been removed.

Love to hear how it went?

Did you go through with the garage conversion to ADU?

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