A tiny solution for many big problems

adu in high density development
With rising popularity from television programming and social media, tiny homes have gained tremendous attention across the United States. An overall paradigm shift to ‘less is more’ has position them as an attractive answer to a growing lack of accessible housing. In the state of Oregon alone there is an expected to be a deficit of over 200,000 homes this year. Specifically in the city of Portland, there are many neighborhoods that benefit from this type of alternative housing. Some of the more common examples of tiny homes use include:

  • Bringing an aging parent who needs additional care onto your property.
  • A first-time homeowner looking to minimize debt or reach financial independence faster.
  • Use as a rental property or Airbnb (where your zoning allows) for extra income.
  • Affordable housing for low-income or rehabilitated residents.

In addition to the list above, a tiny home can save you precious time and money. Most tiny homes are built in a shop with a factory like assembly. This is an efficient process that costs less and can produce a quality-built home much more quickly that a home built on-site.

Portland’s process for permitting an accessory dwelling unit

The City of Portland’s jurisdiction is large and stretches from the North St Johns area to the SW Hills and down to the Burlingame neighborhood. It also stretches east to the NE Parkrose neighborhood and out toward Gresham as far east as NE 160th Ave or SE 176th Ave.

Though Portland is favorable towards accessory dwelling units, it also has a reputation for being a challenging jurisdiction to obtain building permits. We’re familiar with the requirements and review process in the city and will try to outline the basics for you.

For a better understanding you might prefer to read our more advanced article – permitting an accessory dwelling unit in the City of Portland is something we’ve become very good at!

Before you get started, it’s important to know if adding an accessory dwelling unit is allowable on your property and what regulations may apply to the accessory dwelling unit to make it a permittable structure. You may find it helpful to reference the Portland Maps app to find more detail on your exact property.

The app has also been recently updated to allow users to filter addresses specifically eligible for tiny homes or ADUs.

The good news is that attached or detached ADUs are allowed in all City of Portland residential zones.

The Portland Zoning Code allows Accessory Dwelling Units, (otherwise known as ADUs) to be added on a site accessory to a house, attached house, or manufactured home in all residential zones, all Commercial zones, and the Central Employment (EX) zone. You can find the pertaining code in Chapter 33.205 of the City Zoning Code.

There are a few restrictions and requirements when adding an ADU to your property that must be met, including the following:

  • The size of an ADU can be up to 800 SF or 75% of the primary dwelling unit’s livable space, whichever is less. If you’re converting a basement into an ADU you’re ADU can be up to the same number of square feet as the primary dwelling unit’s floor directly above the basement.
  • Height of the ADU cannot exceed 15 feet without requiring some additional standards for the ADU’s exterior design that must be met.
  • There’s a limited number of occupants that can live in both the primary residence and the ADU. The total number of occupants for both units is considered a “household” in the City of Portland. A household’s occupants cannot exceed the number of persons related by blood, marriage, legal adoption or guardianship, plus not more than 5 additional people.
  • Building coverage of an ADU may not be larger than the building coverage of the primary residence. Combined building coverage for all accessory structures may not exceed 15% of the total site area.
  • An ADU must be 40 feet from the font lot line or behind the rear wall of the primary residence.
  • All ADU’s must be compatible with the look and scale of the existing home.

We’ve worked in a variety of neighborhoods throughout Portland, including the Piedmont neighborhood off Rosa Parks Way on the north side as well as the NE neighborhoods of the Beaumont-Wilshire area out to the Wilkes Community Group off HWY 84 and NE Halsey. The SE side of Portland also offers wonderful areas like the Eastmoreland and Woodstock neighborhoods, as well as the Hosford-Abernethy neighborhood that includes some beautiful historic areas like Ladd’s Addition, helping to further increasing home values, which can be excellent for accessory dwelling units intended for rental purposes.

Rules and regulations vary by zoning

In the areas zoned R-7 and R-10 the lots will run between 7,000-10,000 square feet and often have enough room to allow for a small ADU.  Even though the larger sized lots can be accommodating to an ADU, most of our Portland projects have been in more of the central Portland neighborhood’s R-5 zones. While these lots are roughly 5,000 square feet, they often have the space for a smaller ADU like a Wolf Industries unit Model B or C.

Once you’ve determined that an ADU is permittable on your property, you’ll need to gather the required documents for submitting your permit application. These will include, but may not be limited to, the City of Portland NSFR (New Single-Family Residences) application packet, a plot plan showing your property and all existing and proposed structures, and your builder’s plan set with engineering.

You’ll need to provide 1 copy of your NSFR packet along with 4 copies of all other required documents. When those are prepared, you’ll take them to the City of Portland Permit Center located at 1900 SW 4th Ave., Portland, OR 97201. The Portland Permit Center can be a very busy place. You should expect the application process to take you 2-4 hours.

Once your application is submitted, the city’s review process will begin. This process typically takes 6-8 weeks. When your permit is ready to issue, you can pick it up on the 2nd floor of the Development Services building as well. The typical fees associated with a Wolf Industries accessory dwelling unit permit are $2,000-$2,500.

Additional information regarding accessory dwelling units in the City of Portland’s related documentation.

Recently completed tiny homes

We’ve had many happy customer’s place a Wolf Industries modular home on their City of Portland properties. The uses have included adding an accessory dwelling unit as an Airbnb near the PDX airport to create additional income, adding a detached office to provide a quiet space to work from home or be creative, as well as bringing an aging parent onto their property, giving the convenience and peace of mind of having their loved one at their fingertips while maintaining privacy for themselves and their loved ones.

Modular Accessory Dwelling Unit

Check out one client’s guest appearance on an episode of the Tiny House Podcast (also produced in Portland) where they discussed the tiny home process and how they decided on a builder.

How Portland’s costs compare to other cities

We provide a 60-minute free consultation to help you determine if your project is feasible and fits within your budget. In this consultation our experts will help you select what Wolf Industries’ model is right for you. We currently have 4 models available to choose from. Each model has a base price with available options to upgrade. Once you’ve made your selections, we can give you the estimated cost of your project.

Once you’ve selected your model, there are also some additional costs to take into consideration. These will include permitting fees, upgraded materials used in construction and design, utility connections for water, sewer and electricity, and the cost of any additional work that may be required to complete your project.  This additional work may include environmental reports required for permitting, such as Geotechnical reports, grading and excavation or installing driveways to access your home and/or decks.  These additional costs can range from 10,000 to 20,000 for a typical project.

For example, if you select a Model B with a base price of   $55,000

and a few upgrade options that total     $5,000

the total cost for the structure itself is   $60,000

Add the cost of permits, foundation, delivery and setup 18,500

Total   78,500.00

If you choose to use the permitting services Wolf Industries offers, we’ll collect a deposit of $4500 to cover the costs associated with permitting fees and labor. If your permitting fees are greater than the $4500 deposit, you’ll be responsible to pay the difference of the fees associated to permit your new home. The permitting fees do not typically exceed $4500 in the City of Portland unless you’re paying SDC fees, otherwise known as system development charges.

Portland has a wonderful SDC fee waiver program for accessory dwelling units that most or our Portland customers choose to participate in, though you should be aware that the SDC waiver program requires you to agree not to use the unit as a short-term rental property for 10 years.

If you’re adding your accessory dwelling unit to open an AirBnB or short term renal, you’ll be required to pay the SDC fees associated with your project and should allow room in your budget for these fees.

Portland property owners within the City of Portland jurisdiction can expect their accessory dwelling unit permit fees to be under $3,000.  Permitting fees for an ADU built by Wolf Industries in the City of Portland typically run between $2,000-$2,500, depending on the building size. As outlined above, the cost of a Model B unit placed in the City of Portland should cost roughly $78,500. This cost will change with the variables associated with your specific project. This lower cost is possible because the house itself is inspected and signed off at a state level through the BDS FAS (Factory Assembled Structures) program. If an ADU was built conventionally onsite, the costs would be significantly higher.

For the sake of this post, we’ll assume your permitting fees are $2,000 in the City of Portland, with fits within the budget outlined above. (Please see the line labeled “permit, foundation and delivery line”)

It’s important to note that the costs associated with your property’s specific needs will vary.  We are happy to help you determine the estimated expense of utility connections and any other variable costs you may incur with your project.  Some of the past requests we’ve received include grading, driveway construction and decks or patios.

Delivering modular homes

When the construction of your Wolf Industries home is completed in our shop; the house will be ready for a walk-through. After completing your walk through, and giving us your approval, and paying the remainder of your outstanding balance, the house is yours, while still insured by us. Once we have your building permit in hand, we’re ready to schedule our first site visit.


This is when our on-site crew is sent out to grade your building site and install the foundation. When the foundation is ready, the house is delivered to your location and the utilities are hooked up.

Once the installation of your home is complete, it will be thoroughly cleaned, and a meeting will be scheduled to hand off your keys. You can expect to find all documents related to your new home to be left inside your home for your review and reference. Your Wolf Industries warranty then begins. This process typically takes 2-5 weeks.

Moving forward with your purchase 

Now you get to relax and enjoy your purchase while enjoying a new energy efficient, beautifully built Wolf Industries tiny home. Spend your days doing what you love rather than spending your free time on home maintenance.  No need to risk your safety climbing a ladder to clean 2nd story windows or roofs. No need to spend your weekends working on repairs and updates that your home requires. Now you can enjoy the savings of a lower mortgage payment with smaller utility bills and spend your extra time and money doing the activities you love or save for your retirement.

If your home was purchased as an investment property, you’re ready to enjoy the benefit of having additional income from your new rental property. The average rent for a 764 square foot 1-bedroom apartment in Portland Oregon is currently $1,538. So, start collecting some additional income with your new Wolf Industries tiny home accessory dwelling unit.

If you’re moving a loved one onto your property so you’ll be able to care for them while maintaining privacy, now you get to enjoy the convenience of having your loved one close by. No more driving across town or traveling long distances to get them the help they need. No need to worry about their safety and well-being. Now you can enjoy the peace of mind that comes with having your loved one literally in your own back yard.