★ ADU Contractor — Portland, OR

Portland ADU Construction: Maximizing Your Property Value

Mighty ADU Company builds Accessory Dwelling Units for homes in Portland, OR. Accessory Dwelling Units add functional space and increase equity for property owners across Portland. Mighty ADU Company constructs every Accessory Dwelling Unit with solid framing and reliable materials. For homeowners in Portland, Oregon, building an Accessory Dwelling Unit is a very practical way to expand living areas. Mighty ADU Company provides Accessory Dwelling Unit services for homes in Portland, Oregon.

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Mighty ADU Company

Portland, OR

Building an ADU in Portland requires a deep understanding of local zoning codes, including the R2.5 residential zones and the R5 residential zones. Mighty ADU Company knows the specific challenges of the Pacific Northwest climate very well. ADU Construction in Portland involves more than just putting up a basic structure because our team crafts durable, energy-efficient living spaces designed to withstand wet Portland winters and maximize natural light. The process for ADU Construction begins with a detailed site assessment. This assessment considers factors like existing utility access, tree protection requirements, and soil conditions common in areas like the West Hills or East Portland. Mighty ADU Company integrates moisture management techniques, such as proper flashing details and rainscreen systems, to make sure the building lasts for 15 to 20 years or more. Every ADU we build is engineered for optimal performance. A well-built ADU provides a valuable asset that stands the test of time and local conditions.

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What We Handle in Portland

Attached ADU in Portland
01

Attached ADU

An Attached ADU is a secondary dwelling unit built directly onto your existing Portland home. When we construct an Attached ADU, the new space will share at least one common wall with your main house. Mighty ADU Company builds every Attached ADU to match the architectural style of Portland properties. Building an Attached ADU allows for the efficient use of existing infrastructure like plumbing lines, electrical systems, and foundations. The process for an Attached ADU can also simplify permitting requirements compared to detached structures. Mighty ADU Company provides Attached ADU services for homes in Portland, OR.

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Detached ADU in Portland
02

Detached ADU

A detached ADU is a standalone structure on your property, separate from the main house, offering independent living space. Mighty ADU Company builds a detached ADU as a separate building on residential properties in Portland, Oregon. This Detached ADU option provides maximum privacy and design flexibility, creating a distinct new dwelling. For homeowners in Portland, Oregon, Mighty ADU Company is here for all your Detached ADU needs.

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Garage Conversion in Portland
03

Garage Conversion

A Garage Conversion transforms an existing garage structure into a fully functional, habitable living space, often including plumbing, electrical, and insulation upgrades. Mighty ADU Company completes Garage Conversion projects throughout Portland, Oregon. This process unlocks significant property value and provides flexible living options without expanding your home's footprint. Mighty ADU Company provides Garage Conversion services for homes in Portland, Oregon.

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ADU Permitting in Portland
04

ADU Permitting

Mighty ADU Company handles the complete ADU Permitting process for homeowners in Portland, Oregon. From the initial application submission to final permit issuance, Mighty ADU Company manages every detail of the paperwork. The process makes sure that your project complies with all local zoning and building codes. Proper ADU Permitting also helps avoid costly delays and keeps construction moving forward on schedule in Portland.

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ADU Design in Portland
05

ADU Design

ADU Design involves creating detailed architectural plans, structural drawings, and material specifications for your Accessory Dwelling Unit. ADU Design in Portland, OR provides a complete design package that makes sure your ADU is code-compliant, functional, and aesthetically integrated with your existing property. Mighty ADU Company provides ADU Design services for homes in Portland, OR.

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ADU Engineering in Portland
06

ADU Engineering

Mighty ADU Company offers ADU Engineering for homeowners in Portland, OR who need structural calculations and civil calculations for an Accessory Dwelling Unit. Structural calculations and civil calculations cover the foundation, the framing, and the utility connections for the Accessory Dwelling Unit. ADU Engineering makes sure that every Accessory Dwelling Unit is built safely and meets all local building codes. Portland weather conditions, such as heavy winter rain and seasonal moisture, require very solid structural planning so the Accessory Dwelling Unit stays stable for 15 to 20 years or more. For homes and businesses in Portland, Mighty ADU Company provides ADU Engineering services.

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ADU Financing in Portland
07

ADU Financing

Mighty ADU Company connects Portland homeowners with reliable ADU Financing options for their Accessory Dwelling Unit projects. ADU Financing covers every phase of the project, including architectural design, engineering, permitting, and physical construction. Securing the proper funding for ADU Financing makes sure that your Accessory Dwelling Unit build progresses without unexpected financial hurdles or costly delays. Proper ADU Financing gives homeowners in Portland the ability to complete their Accessory Dwelling Unit project from start to finish.

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ADU Construction Management in Portland
08

ADU Construction Management

ADU Construction Management involves overseeing every aspect of your Accessory Dwelling Unit build, from permitting through final inspection, making sure that there is strict adherence to the approved design and the established budget. Mighty ADU Company provides ADU Construction Management services for homes in Portland, Oregon. This structured oversight keeps your ADU Construction Management project on schedule and within financial parameters, minimizing stress and unexpected complications. For homeowners in Portland, Mighty ADU Company is here for all your ADU Construction Management needs.

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Junior ADU (JADU) in Portland
09

Junior ADU (JADU)

Mighty ADU Company constructs a Junior ADU (JADU) for properties throughout Portland, OR. A Junior ADU (JADU) is an interior conversion of existing living space, typically a bedroom or a den, into a self-contained unit. The unit features a kitchen, a bathroom, and a separate entrance. A Junior ADU (JADU) provides an affordable and compact living solution for Portland residents. Property owners can use a Junior ADU (JADU) to generate rental income or to house family members within the current home footprint.

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ADU Site Assessment in Portland
10

ADU Site Assessment

ADU Site Assessment is an important service for homeowners in Portland, Oregon who want to build an Accessory Dwelling Unit. Mighty ADU Company provides ADU Site Assessment services for homes in Portland, Oregon, to determine if a property is suitable for construction. Our ADU Site Assessment includes a thorough review of zoning rules, utility access, and buildable area. This foundational step identifies potential challenges and opportunities on your land, giving you a clear path forward for your ADU project in Portland. When our team performs an ADU Site Assessment, we look at property lines, setback requirements, and existing structures. We also evaluate sewer connections, water lines, and electrical capacity. For homeowners in Portland, Oregon, Mighty ADU Company is here for all your ADU Site Assessment needs.

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Portland's Local ADU Contractor Experts

Mighty ADU Company is proud to serve Portland, OR and the surrounding communities. Our reputation is built on honest work, clear communication, and results that hold up over time.

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Frequently Asked Questions

The typical timeline for building an ADU in Portland, from initial design to final occupancy, ranges from 8 to 14 months. This timeline includes 3 to 6 months for design and permitting with the Portland Bureau of Development Services (BDS), followed by 5 to 8 months for construction. Factors like site complexity, specific design choices, and the current BDS review queue can influence this duration. Mighty ADU Company works to streamline the permitting phase by submitting complete and accurate plans from the outset, which helps avoid delays.
The cost to build an ADU in Portland, Oregon generally ranges from $200,000 to $400,000 or more, depending on the size of the project, the interior finishes, and the specific site preparation needs. When homeowners look to build an ADU, the total budget includes design fees, permitting costs, utility connections, and actual construction. For example, a detached 600 square foot unit with standard finishes is usually at the lower end of that price range. On the other hand, a larger, custom-designed unit with high-end materials and complex utility trenching is at the higher end of the scale. Mighty ADU Company provides a detailed cost breakdown after a thorough site assessment and design consultation for projects in Portland, Oregon.
Portland zoning requirements for ADUs are favorable for property owners, allowing one ADU on any residential lot with a single-family home in residential zones. Key regulations include a maximum ADU size of 800 square feet or 75% of the primary dwelling habitable space, whichever is smaller, alongside specific setback requirements that vary by zone. There are also height restrictions, limiting ADUs to 20 feet or the height of the primary structure. Mighty ADU Company navigates these specific codes, making sure your project meets all city and county regulations in Portland, OR.
Building ADUs in Portland typically does not require separate utility connections for water, sewer, and electricity. These ADUs can often tie into the existing services of the primary dwelling. A separate electrical sub-panel is usually installed for the ADU to handle power needs safely. Sometimes a separate water meter is desired for rental purposes when renting out the space. Gas lines, if applicable, can also be extended from the main house to the ADU. Mighty ADU Company assesses your existing utility infrastructure during the initial site visit. The initial site visit allows our team to determine the most efficient and cost-effective connection strategy for homes in Portland, Oregon.
For an ADU in Portland, Oregon, a poured concrete slab-on-grade foundation or a crawl space foundation with stem walls are both very common options. A slab-on-grade foundation offers very good thermal mass and can be more cost-effective, especially on level sites. This option requires careful sub-grade preparation for proper drainage, including grading and gravel layers. A crawl space foundation provides easier access for future utility work and can better accommodate sloping lots. A crawl space also allows for solid insulation against moisture, keeping the structure dry during the wet Portland winters. Mighty ADU Company evaluates your specific site soil conditions and drainage patterns to recommend the best foundation type for long-term stability and moisture control.

Proudly Serving Portland and the Surrounding Area

From Portland to the surrounding communities, we bring the same level of care and craftsmanship to every job — whether it's a quick repair or a full project.

Unlock Your Property's Potential. Start Your ADU Journey.

Schedule a free site consultation with Mighty ADU Company to explore your options for an Accessory Dwelling Unit and receive a preliminary project assessment for your property in Portland, Oregon.

Get Your Free Quote 503-608-4664