Building an ADU in Portland, Oregon: ADU Laws, Codes & Permits

Introduction to Building an ADU in Portland

Accessory Dwelling Units (ADUs) in Portland, Oregon, offer a unique opportunity for homeowners to maximize their property’s potential. An ADU is a secondary housing unit on a single residential lot. It can be created by converting part of an existing house, converting a garage, or constructing a new building. This guide delves into Portland’s specific regulations and requirements for ADUs, providing essential information for homeowners looking to embark on this venture​.

Types of ADUs and Conversion Options

ADUs in Portland come in various forms, including detached units, attached units, and conversions of existing spaces like basements or garages. Each type has its own set of design and size regulations. It’s important to evaluate the existing space for compliance with building codes, particularly regarding ceiling height, emergency egress windows, insulation, ventilation, and stairs​.

Portland ADU Permitting Process

A crucial step in building an ADU in Portland is obtaining the necessary permits. A building permit is mandatory for converting spaces into living areas or constructing new ADUs. Additionally, electrical, plumbing, or mechanical permits may be required based on the project’s scope. Adding an ADU could significantly increase your property value and property taxes.

Research and Compliance

Before construction, homeowners should research their property’s permit history and understand zoning standards, which may affect ADU design and usage. Limitations on short-term rentals and home occupations, ADU size limits, and design requirements, especially for new detached ADUs over 15 feet tall, must be considered​.

Utility Connections and Construction Standards

ADUs require independent water supply and sanitary sewer systems, except in specific cases allowed by Portland’s Water and Environmental Services. The construction must comply with the Oregon Residential Specialty Code (ORSC) and, in certain cases, alternative construction standards outlined in the Accessory Dwelling Unit Code Guide​.

Portland ADU Contractor and DIY Considerations

Contractors working on ADUs in Portland, Oregon, must be licensed. Homeowners can undertake some work themselves, but a licensed contractor must do electrical work. The Oregon Construction Contractors Board (CCB) is a valuable resource for finding licensed Portland ADU contractors​.

Financial Aspects: Fees and SDC Waiver Program

Building a Portland ADU involves various fees, including building permit fees, water service fees, and System Development Charges (SDCs). SDCs, levied by several bureaus, vary depending on the project. However, homeowners may be eligible for an SDC waiver, offering financial relief in certain circumstances​.

Permit Application and Approval Process

Applying for an ADU permit involves submitting a building permit application, site plan, and architectural plans. The process varies slightly for new constructions and conversions. Applications can be submitted online or in person, with electronic plans generally submitted through the Single PDF process​.

Inspections and Final Steps

Once a permit is issued, inspections are crucial to ensure regulation compliance. Homeowners must schedule inspections and respond to any required corrections. The final approval inspection is necessary to complete the permit process​.

Other Considerations

Additional factors, such as tree preservation requirements, temporary street use permits for construction, and addressing requirements for ADUs, play a role in the overall process. It’s also essential to understand the regulations for discontinuing using an ADU or converting existing accessory rental units to meet new standards​.

Building an ADU in Portland requires careful planning and adherence to city regulations. From understanding zoning laws to navigating the permitting process, this guide offers a roadmap for homeowners looking to expand their living space or investment opportunities through ADUs. With the right preparation and guidance, adding an ADU to your Portland property can be rewarding.

Contact Shelter Solutions Today To Learn How We Can Make Your Portland ADU A Reality!