Accessory Dwellings

A one-stop source about accessory dwelling units, multigenerational homes, laneway houses, ADUs, granny flats, in-law units…

One Year In, Are Tiny Houses on Wheels the New ADU in Portland?

We are one year into installing RV hookup infrastructure on residential properties in Portland for homeowners who are adding a mobile dwelling. We do this work through a company called Tiny Hookups LLC. This company was formed on the heels of the legalization of RVs (and tiny houses on wheels, which are classified as RVs under Oregon state law) as a legal dwelling option in Portland, Oregon, in 2021. 

January 11, 2023 · 2 Comments

10 Ways Your ADU Can Support Your Retirement

As I’ve interviewed homeowners, designers, and builders about ADUs over the past several years, one thing that has impressed me is how many people are using an ADU as part of their retirement plan. ADUs can provide housing flexibility, additional income, one-floor living to age-in-place, proximity to family members and caretakers, or even just a place to call home when traveling.

February 4, 2022 · 1 Comment

Design Your ADU Through Yestermorrow

Accessory Dwelling Unit Design (ADUD) will help you envision and design a backyard cottage, guest house, or in-law suite that meets your needs. We’ll virtually tour noteworthy accessory dwellings, spark a dialogue about space-saving strategies, and engage in an imaginative process with interactive design exercises. In the “design studio” you’ll learn a variety of tools to help you communicate your ideas. Students completing this course will have the skills necessary to continue work on their own ADU projects. Bring your curiosity, enthusiasm, and project ideas!

January 11, 2022 · Leave a comment

Portland, Oregon’s ADU Permit Data for 2020

As of July, 2021, there have been approximately 3,350 total permits issued for ADUs in Portland. Here’s the latest annual permit trend chart. 

July 22, 2021 · 2 Comments

The Three Facts of California’s ADU Boom

Accessory dwelling units (ADUs) in California are “a revolution in progress,” in the words of researchers at the University of California’s Center for Community Innovation. A series of laws enacted over the past five years have systematically eliminated most explicit and implicit legal barriers to ADU construction across the entire state. Using data reported to the California Department of Housing and Community Development, I investigated likely economic and regulatory determinants of ADU growth across California cities.

June 10, 2021 · 2 Comments

Tiny Houses and RVs To Be Allowed as Housing in Portland

On April 28th, 2021, Portland’s City Council unanimously passed a new set of regulations that allows for recreational vehicles and tiny houses on wheels to be used as a legal, viable housing option on residential properties in the City of Portland beginning on August 1st, 2021.  

April 28, 2021 · 8 Comments

Liberalized ADU laws must be defended in court

Recent legal developments show that we need to do more to ensure that permits are, in fact, being issued and new ADUs can be built.

April 8, 2021 · 1 Comment

ADU Legislative Initiatives- History in the Making (Part IV)

On August 12th, 2020, the City of Portland finally passed the Residential Infill Project. This was an overhaul of single family residential zoning regulations that was nearly five years in the making. This post will cover the changes that are coming with Residential Infill Project and also tease you with what is to come with Oregon’s House Bill 2001.

August 17, 2020 · 10 Comments

Rate of Inhabited Mobile Dwellings on Residential Properties in One Portland Neighborhood

In June, 2020, I conducted some voluntary research to determine how many single family residential properties had an inhabited mobile dwelling. The Cully neighborhood consists of 12,595 residents, or 4,685 households. My survey found 65 inhabited mobile dwellings located on residentially zoned lots, which translates to a rate of 0.005/resident.

July 17, 2020

Rent Control, PDX Ordinances and Recent Legislation Impacting ADUs.

Over the past five years there have been new laws passed in Portland and Oregon targeting the residential rental market. This article will provide context on the passage of these laws, inform ADU owners how the laws affect their properties, and give guidance on how owners can best stay in compliance. 

February 28, 2020

Incremental Updates for ADUs for 2020

Here’s some notable stuff for those interested in ADU minutiae in the Portland market and beyond. It’s a mashup of information and updates that will be of interest to ADU advocates: ADU Permit Numbers, MLS, Mapping ADUs, SDCs, ADU events in April 2020, Summit videos, oh my.

January 8, 2020 · 4 Comments

ADU classes for Portland homeowners- postponed due to Coronavirus- Special offer for Portland Metro locals

Kol Peterson, one of the editors here, hosts a class called “Building An Accessory Dwelling Unit on your property,” on Please visit Kol’s site for more details.

December 10, 2019 · 2 Comments

ADU Advocates’ Unsanctioned Guidance for Oregon Cities Updating Local ADU Regulations by January, 2020 to Comply with HB 2001 Statute

Two of the most common “poison pills” in ADU standards will be prohibited statewide in Oregon beginning in January, 2020, making earlier ADU legislation significantly more effective.

Oregon House Bill 2001 (HB 2001) was signed into law on August 8th, 2019. While HB 2001 rightly claimed headlines for expanding missing middle housing options, it also included some specific requirements for ADUs. 

November 18, 2019 · 8 Comments

Consider Going All-Electric For Your ADU

Natural Gas, or methane has been promoted both as a ‘Clean Fuel’ or a ‘Bridge Fuel’ in various circles, both locally and nationally during this time of climate crisis. Concurrently, the IPCC has called for a far more rapid decline in the use of fossil fuel, more rapid scaling up of renewable energy taking advantage of the falling costs, and avoiding a lock-in of high-carbon infrastructure.

November 13, 2019 · 1 Comment

Perspective: How to make accessory dwelling units affordable

ADU financing could — and perhaps should — be a lot more like commercial real estate financing, only with a human touch. A guest post by Roger A. Gins.

November 6, 2019 · 6 Comments

ADU Legislative Initiatives- History in the Making (Part III)

Several significant bills passed through the legislative process in California last week. This legislation that passed in CA is major and will help usher ADUs out of the dark ages.

September 18, 2019 · 11 Comments

ADU Legislative Initiatives- History in the Making (Part II)

As reviewed in my first post on this topical thread, significant and progressive legislative and regulatory ADU code overhauls are occuring at quickening pace in jurisdictions up and down the west coast. I’ve been tracking ADU regulatory reform fairly closely for a decade, and there hasn’t ever been a time period where ADUs have been gaining as much national traction as they are now.

August 22, 2019 · 3 Comments

Announcing the next Build Small Live Large Summit and the next ADU Academy. November 7th and 8th, 2019. Portland, Oregon.

Two national, back-to-back events on November 7th and 8th in Portland, Oregon

August 11, 2019

Recap of 2019 ADU Tour

The ADU Tour in June was a blast. Approximately 800 people attended. We’ve made the 17 project profiles public. You can find them here.

July 23, 2019 · 5 Comments

ADU Legislative Initiatives- History in the Making (Part I)

The 24-hour period from the afternoon of Sunday, June 29th- afternoon Monday, June 30th, 2019, was an important day for ADUs. 

In the future, urban planners will point to that day as a signature moment for an era of deregulation and liberalization of codes for ADUs. 

July 8, 2019 · 13 Comments

ADU Development Costs Keep Going Up

I’ve updated an extensive post about ADU development costs here. These updates are based new cost numbers that just came in from the upcoming 2019 ADU Tour in Portland, which serves as a repository of current and active primary source data for cost estimates. It turns out that current primary source data is critical when it comes to talking about the costs of ADUs, because the development cost numbers here keep escalating rapidly.

May 28, 2019 · 10 Comments

2019 is the Year of ADU Financing Innovation

Financing ADUs has remained a major challenge. But, in the future, 2019 will always be thought of as the year of ADU financing innovation. On April 29th, Portland State University convened a meeting in Washington, D.C to help flesh out some of the innovative programs that are being developed to finance ADUs. 

May 16, 2019 · 3 Comments

Seventeen ADUs!

I don’t know what I was thinking.I couldn’t help myself. I kept saying yes; I couldn’t resist. Now, look what I’ve done.Maybe you’re wondering what am I talking about. I’m talking about this year’s ADU Tour, of course!

April 29, 2019

New ADU Financing Option with No Monthly Payments

One provider of ADU financing describes their service.

April 22, 2019 · 3 Comments

Announcing Accessory Dwelling Academy and The ADU Tour

On June 21st, 2019, we are running a new professional education event designed for builders, designers, lenders, realtors and appraisers who aspire to up their ADU game and stand out from the competition.

February 11, 2019 · 2 Comments

ADU Permit Trends in Portland in 2017 and 2018

This post details some findings about ADU permit trends in Portland.

First, we’ll start with the big picture. Here’s the latest data on the number of permits issued by the City of Portland for ADUs from 2000-2018. In 2017, 588 permits were issued. In 2018, 660 were issued. This is a total of 1248 ADU permits issued in 2017 and 2018.

January 14, 2019 · 6 Comments

ADU Rental Income Can Be Used to Qualify Borrowers to Purchase on HomeReady Loans

A HomeReady Mortgage is a Fannie Mae, first-time home buyer loan program, with minimum down payment requirements, and some very particular underwriting characteristics. When a borrower is purchasing a single-unit primary residence with a 3% minimum down payment and there is an ADU present, 75% of the potential rents from the ADU can be used to qualify.

July 6, 2018 · 1 Comment

ADU Legislative Initiatives Abound

SDC Waiver, Residential Infill Project, Oregon and California state legislative updates….

There are significant ADU legislative initiatives underway in California, Porltand, and Oregon at large. Each of these legislative efforts have national signficance.

May 2, 2018 · 5 Comments

Basement/Garage Conversion Open House on Thursday, April 19th

For those of you in Portland, I’m having an open house event this Thursday, April 19th at my recently completed basement/garage conversion ADU from 4-7pm. I hope to see you there.

April 16, 2018 · 1 Comment

Accessory Dwelling Units: A Tale of Two Cities

Guest post by Mark Thieroff from St. Paul, MN

About five years ago, interest in accessory dwelling units had reached a critical mass in Minneapolis and St. Paul. ADUs were seen by proponents as a way to increase housing diversity and flexibility and add density in residential neighborhoods. But Minneapolis and St. Paul ended up taking very different approaches and, consequently, have seen markedly different results.

April 3, 2018 · 1 Comment

Backdoor Revolution – Part I – Origin

In 2013, I was observing ADU trends in the US by tracking Google News Alerts and reading academic articles….

I’ve spent the last 2.5 years on this book, and I am proud to finally release it to the world on January 23rd, 2018.

January 8, 2018 · 6 Comments

Building an ADU in L.A.- Part II (excerpt)

Between 2003-2016, an average of one hundred permitted ADUs had been developed each year in L.A.. While 100 ADUs a year is something, it’s certainly not a lot of housing for a city with a population of nearly four million people, and 1.4 million housing units. But, 2017 has entirely changed the landscape for ADUs in California at large. And, L.A. has done something that no one expected. 

DRUM ROLL……

October 19, 2017 · 2 Comments

The First National ADU Summit on November 3-5 in Portland

The Build Small Live Large Summit is the first ever national gathering of leaders in ADU policymaking, design and development. ADU industry practicioners across the country will convene to share and showcase emerging best practices regarding the development of this rare housing type. If you are an ADU enterprenuer, designer, builder, policy-maker, or advocate, we hope that you will be able to attend. 

September 26, 2017

2017 ADU Tour Wrap-Up

The ADU Tour in Portland on September 9th and 10th was great. 600 people each day attended to see the 12 ADUs featured in NE Portland and the 12 ADUs in SE Portland. 

September 12, 2017

Garden Suites in Edmonton: a private investment in the public good

New research from Canada finds that ADUs and garden suites can function as voluntary version of affordable housing — with some important caveats.

September 8, 2017 · 2 Comments

ADU Tour on September 8th-10th

The ADU Tour is just a couple weeks away on September 8-10th. If you are planning to build an ADU, drop whatever else you have planned and clear your schedule for this weekend. This is the largest (and best) ADU Tour in the nation.  

August 24, 2017 · 1 Comment

ADU Tour- Early bird sales end August 19th

Eary bird sales for the ADU Tour end on August 19th. You can buy tickets now.

It’s shaping up to be an awesome event! There’s going to be 12 ADUs featured on Saturday in SE and 12 ADUs on Sunday in SE. For those who are only interested in seeing certain ADU structural types, here is the breakdown by day.

August 3, 2017 · 1 Comment

Building An ADU- a new website for those seeking to build ADUs

BuildinganADU.com is a website geared to homeowners who want to build an ADU on their property, featuring posts and tips that delve into great detail about explaining how much ADUs cost to build using actual costs from recent projects,

July 3, 2017

Announcing the 2017 ADU Tour

We are excited to announce the next ADU Tour. This tour has an awesome line up, chock-full with awesome and diverse ADU types and styles.

It’s going to be a full weekend event with 10+ ADUs in NE Portland featured on Saturday, and a different set of 10+ ADUs in SE Portland on Sunday. None of these ADUs have been featured on previous ADU tours before.

April 24, 2017 · 3 Comments

PCC ADU Design Class May 6-7, 2017

This spring Lina Menard, Coordinator of the ADU Case Studies Project and owner of Niche Consulting, will be teaching Accessory Dwelling Unit (ADU) Design Course. In this intensive two-day workshop we cover many of the considerations for designing a small space, visit with special guests who have created ADUs, and go through a set of design exercises to help you develop a design of your own.

April 17, 2017 · 2 Comments

The Ascent of ADUs in Portland 

Portland is leading the pack with ADU development nationally. Data provided by the City of Portland shows the rate of ADU permits issued from 2010-2016. In 2016, 615 permits were issued, 20 times the average number of permits issues each year before Portland’s SDC waiver in 2010.

February 27, 2017 · 19 Comments

PCC ADU Design Wraps Up

This past weekend Lina Menard, one of our editors and the coordinator of the ADU Case Studies Project, taught an ADU Design Class through Portland Community College. The fourteen students brought a variety of project ideas, including everything from garage and basement conversions to backyard cottages, additions, and renovation of a workshop.

February 7, 2017 · 3 Comments

ADUs’ Tiny Relatives

Editor’s note: In a stunning turn of events, Portland has actually just moved ahead with some of the ideas described in the post and video below, temporarily ending enforcement of the habitation of mobile dwellings on residential properties.

November 22, 2016

Follow Up to the September 2016 ADU Tour

The ADU Tour on September 18th was a great event! Over 700 people registered and attendees had a fabulous experience. We aim to make the tour as educational as possible for attendees. Following the tour, we received many comments in the feedback, like this one.

September 27, 2016 · 3 Comments

The ADU Tour is Less Than One Week Away

The weather looks like it will be awesome for next week’s city wide ADU Tour. The ADU Tour hosts are excited to open their doors for the tour. In addition to … Continue reading

September 12, 2016

It’s Time to Register for the September 2016 ADU Tour

The City-wide ADU Tour is less than six weeks away, and early bird ticket sales end on September 2nd. On the tour, you’ll meet homeowners who have recently completed their ADUs, who … Continue reading

August 10, 2016

Save the Date: ADU Tour–September 17th & 18th

The ADU Tour is on for September 17th & 18th, 2016. Learn more and register here. This will be the fourth city wide tour of ADUs. 10+ ADUs will be … Continue reading

June 20, 2016

ADU Storage Solutions

I’ve picked up lots of small space storage solutions over the past couple years as I interviewed ADU homeowners and designers for the ADU Case Studies Project. You may just have to read through the whole set of case studies to see ALL the clever ideas, but here I’ll pick out my top 10 favorites.

May 27, 2016 · 15 Comments

Tips for Basement to ADU Conversions

Read on to learn about the benefits of basement ADUs, find links to examples of basement ADUs, and become familiar with what the deal-breakers are if you’re considering converting a basement into an ADU.

May 6, 2016 · 3 Comments

The Second Coming of Detached ADUs in Portland

Readers of this series may have noticed a positive tone change in the dire title of the series. That’s because yesterday, the Oregon Department of Revenue issued a draft rule that steers Multnomah County away from the misguided interpretation that they’d used this year–the interpretation that had caused detached ADUs to trigger a property reassessment– the interpretation which has caused a dramatic ADU development chilling effect in Portland in the last 6 months.

April 27, 2016 · 12 Comments