We're Everything You Need in an ADU Builder

If you’ve been looking for a modern, stylish ADU for your backyard, you’ve come to the right place. Relevant Buildings is an ADU builder in the Portland, Oregon area. We build ADUs throughout Oregon and Washington. From financing help, design, permitting, and building, we provide everything you’ll need to make your ADU dream a reality. Our goal is to make your home building journey as easy as possible. While we specialize in shipping container ADUs, we also offer stick-built and pole barn style ADUs.

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ADUs That Are Built to Last

Our company is driven by a mission to create long-lasting, environmentally conscious housing. We also realize that flat, buildable land is getting harder to find, while the need for housing continues to grow. We decided to become an ADU builder as a solution to both of those issues. ADUs are a sustainable living option because they are smaller than traditional single-family homes and they share the land and utilities devoted to the primary home. This means they require fewer resources to build and maintain.

Our specialty is using upcycled shipping containers to build durable ADUs. Building small homes, installing energy-efficient appliances, and utilizing super-efficient insulation and mini split systems are just a few of the methods we use to make our homes eco-friendly.


Costs and Financing

We break down pricing for our container homes on our Price List page. This gives you a good idea of what each home will cost based on size and level of completion. Aside from the cost of the container home, you will also have costs for permitting, delivery, foundation, and other site work that are specific to your project. The good news is that ADU builds often cost less than building a new primary home because you already own the land and can often share utilities that the existing home uses.

This is a common question we get, and a topic you’ll also see discussed in social media circles. Most ‘inexpensive’ container homes that you see online are not built to code. We’ve had a handful of people reach out to us asking if we can help them legalize a container home that they bought from someone else that does not meet code standards. In those cases, people tend to regret buying these unpermitted, illegal container homes and end up spending a lot of money, time, and headache trying to bring their homes up to code.

Ultimately, our costs go into providing durable and comfortable buildings that carry the State Insignia for safe and legal prefabricated structures. This allows you to fully permit, finance, and insure your investment, giving you peace of mind for years to come.

Yes, we have sold several homes now that have qualified for ‘take out’ or ‘mortgage’ loans like those of standard site-built homes. We also partner with a local nonprofit lender that specializes in ADU lending. Since our homes are fully permitted, most lenders can provide loans. Construction financing is difficult regardless of the type of home you plan so it is best to discuss this with us individually. In general, however, if you have 20% of the necessary costs for a building project and good credit, lending is available.

If you don’t have a preferred bank, we can direct you to lenders that we’ve worked with.

The total cost to the buyer as estimated by RBC will typically include the fully finished unit (including all electrical and plumbing, kitchen cabinets, counter tops, appliances, flooring, mini-split heating and A/C, insulation, and drywall), the foundation, and shipping (dependent on distance). The estimate will not include local permit costs or ‘site improvements’ such as road work, clearing, SDC fees, septic systems or wells, etc.

Site costs vary by model, complexity, distance of delivery, and level of finish requested by the customer. In general, we estimate a range of $30-50,000 to provide an ‘all-in’ number for site work services. Decking and porches are normally not considered in this estimate. We can be more specific once we review your site and determine the scope of work involved.


Pricing for homes includes Oregon State BCD or Washington State L&I approved plans for our standard models. However, permits for custom homes or for site work such as foundation, utilities, and SDCs are not included. We offer permitting services at an hourly rate to make modifications and acquire permits for placement of homes on lots anywhere in Oregon or Washington.

The buyer is responsible for obtaining permits for site work. However, RBC offers permitting services to secure the site permits upon the buyer’s request. Most of our customers choose to forgo the headache of getting their own permits and ask us to handle local permitting. There will be an hourly charge for our time, and the local jurisdiction’s permit costs must be paid by the homeowner.


ADUs go by many names: guest house, in-law suite, casita, and many more. ADU stands for accessory dwelling unit, which means a smaller home that is “accessory” to your primary residence. Relevant Buildings is an ADU builder that specializes in building detached ADUs, which are stand-alone homes separate from the main home. Detached ADUs are typically placed in the backyard and are about 800 sq. ft. or less. You can refer to your local planning department for specific ADU guidelines and requirements for your property.

Yes, Relevant Buildings is an experienced ADU builder. We have several ADU options to choose from. ADUs are known by many names – guest house, in-law apartments, or granny flats, for example. The full name for an ADU is an Accessory Dwelling Unit. An ADU is a permanent secondary home which provides fully arranged living space in the backyard or on the side of existing homes. ADUs generally have at least one bedroom, bathroom, and kitchen space, and are normally under 800 SF.

Recently, there’s been some encouraging zoning law changes throughout Oregon and Washington that make it easier to permit and build ADUs, particularly in Portland. RBC also works with a lender that specializes in financing ADUs in the Portland Metro area. ADUs are a great option for inter-generational living or additional income from renting. If you’re interested in building an ADU, now’s a great time to get started.

Your local planning department will have specific rules about what an ADU can look like and where it can be placed. In general, most lots that allow “single family” or “multi-family” homes also allow ADUs, especially if your property is closer to an urban area. Rural areas tend to have more restrictions regarding ADUs, especially if you are on farm, forest, or agricultural land. Besides local zoning requirements, you’ll also want to be sure your yard has enough space for the size of the ADU that you want to build.

If you’re interested in building an ADU on your lot but aren’t sure what your local requirements are, please reach out to us using our Tour / Contact form, and we’ll get back to you right away. As you local ADU builder, Relevant Buildings can take a look at your property and let you know if your zoning code will allow ADUs!

We love ADUs for a number of reasons. They are an excellent option for people looking for private, affordable housing for aging parents, other family members, or guests. ADUs can also be a source of income by renting out the ADU or downsizing to living in an ADU and renting out your main residence. Accessory dwelling units are a sustainable living option because they are smaller than traditional single-family homes and they share the land and utilities devoted to the primary home, which means they require fewer resources to build and maintain. Adding an ADU to your lot also increase the overall value of your property.

As an ADU builder, we take pride in providing high quality homes that fit your needs. Our goal is to make the home building process as pain-free as possible so you can simply enjoy your new home. Relevant Buildings provides everything you’ll need to build your ADU, including design, permitting, financing, and building. We offer a variety of options to help fit most budgets. We’ve also developed relationships with lenders that offer excellent financing for ADUs. Most importantly, we’ve got experience on our side, having built over 60 container homes and counting.

Insulation, Efficiency, and Solar Options

We primarily use high-quality, environmentally friendly, closed-cell spray foam insulation. This results in a high R-value per square inch, which means excellent temperature regulation as well as protection from condensation. We insulate our homes and ADUs to exceed building code standards by at least 10%.

Our container homes have several defenses against condensation and rust. We protect the interior container walls from condensation and rust by applying a generous layer of closed-cell spray foam insulation, which is waterproof. We also install energy recovery ventilators (ERVs) in our homes to provide ventilation and help circulate fresh air into the living space. Only inert materials (such as vinyl or closed-cell insulation) are in contact with the container proper. Window openings are connected to a metal window frame and the interior wall using pressure-treated wood. We cover the exterior walls of the container with marine-grade paint to prevent rust. Dependent on your property’s location, we also recommend building a sloped roof over your container home. This will ensure the tops of the containers are covered and lessens your risk of rust forming.

Yes, all our units include ductless mini splits for energy-efficient heating and cooling.

All our homes are built to Energy Trust Standards. We can provide certification if requested before the building is started, as third-party inspections are required. Energy Trust standards include a thermal shell that is 10% higher than code, fresh air to the house, and other considerations for an energy-efficient and healthy home.

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