FAQs
Answers before you get started.
Common questions about ADUs, property requirements, costs, and the building process in the Columbia Gorge. Every property is different - these answers are a starting point for understanding your options.
01 - ADU Basics
Start here
What an ADU is and what you can build.
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An accessory dwelling unit, or ADU, is a secondary home on the same property as a primary residence, with its own kitchen, bathroom, and living and sleeping space. Depending on local requirements, it may be attached to the main home, created within existing space, or built as a separate structure.
ADUs can provide space for family, guests, or long-term rental housing. A standalone office or studio without independent living facilities is not necessarily an ADU.
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A detached accessory dwelling unit, or DADU, is an ADU in a separate building from the main home. Examples include a backyard cottage or an approved apartment above a detached garage. It provides independent living facilities, including a kitchen and bathroom.
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ADU is the general term. DADU describes an ADU that is detached from the primary home. All DADUs are ADUs, but not all ADUs are detached.
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Our current collection includes Modern, Cottage, Craftsman, Fire-Resistant, and Entry studio. Each model has its own architectural character and available exterior options.
Explore our ADU Designs page to compare the models. Changes beyond the available options are discussed separately, including their implications for scope and budget.
02 - Your Property
Building on your land
Feasibility, zoning, size, and site conditions.
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It depends on:
County and zoning regulations
Lot size
Utility access
Septic or sewer capacity
Scenic Area restrictions
Setback requirements
Eligibility depends on your property’s jurisdiction, zoning, existing development, access, utilities, wastewater capacity, and any applicable Scenic Area requirements.
Start Your ADU Project to share your property information and design preferences, or contact us directly if you have questions. We’ll review what you share and help identify the appropriate next step.
Reports can be sent to:
quantumbuildersnetwork@gmail.com
info@gorgeadu.com -
The allowable size depends on the jurisdiction and zoning that apply to your property. City and county requirements can differ, even within the same general area.
A model’s availability does not mean it can be approved on every property. We review the applicable requirements before confirming whether a design is a suitable starting point.
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Height limits depend on:
Zoning
Setbacks
Roof design
Scenic Area restrictions
Site-specific conditions
Height limits depend on the applicable zoning, building location, setbacks, and any additional site restrictions. We consider these requirements alongside the proposed roof form and design before confirming what may be possible.
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Possibly.
If the existing septic system has enough remaining capacity, the ADU may be able to tie into it. This typically requires:
Septic evaluation
Capacity verification
County approval
In some cases, upgrades or system expansion may be required.
03 - Cost & Timeline
Budget and timing
What to plan for and how long it takes.
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ADU costs depend on the design, site preparation, access, utilities, wastewater requirements, finishes, and permitting and engineering needs.
We discuss your budget alongside your property and goals to help define a realistic project scope. Choosing a model or submitting project information does not provide a construction quote.
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The Initial Viability Review is $1,000. If the property is determined to be non-viable for an ADU project, there is no charge.
This is a separate service from submitting your initial project information.
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Permitting timelines depend on the jurisdiction, the completeness of the application, and the reviews required for your property. Planning, building, wastewater, and Scenic Area reviews may involve separate steps.
We help identify the required approvals and discuss timing as the project scope becomes clearer. Approval dates cannot be guaranteed.
04 - Working Together
Working with us
How we collaborate on your project.
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Homeowner participation may be possible, depending on the work involved, experience, safety requirements, and construction schedule.
Any homeowner-performed work must be discussed and agreed upon in advance. Responsibilities, inspections, and any applicable warranty limitations are documented in the project agreement.
