Thinking about adding an ADU in Anacortes to create space for family or add long-term rental income? It is a smart move, but small missteps with zoning, utilities, or permits can cause big delays. This quick guide shows you what to check first, how the permit path works, what it may cost, and the pitfalls to avoid so you can move forward with confidence. Let’s dive in.
ADU basics in Anacortes
Anacortes allows accessory dwelling units in residential zones with a single-family house, with standards for size, height, setbacks, and parking in the city code. The current ADU chapter lists a maximum size of 900 square feet, height limits for detached ADUs, and parking that can require up to three off-street spaces unless on-street parking abuts the property. Always verify the latest rules in the city’s ADU chapter because the city has been updating regulations. Review the current text in the Anacortes Municipal Code on accessory dwelling units.
In January 2024 the city removed the owner-occupancy requirement for properties with ADUs. You can confirm the ordinance and other recent changes on the Legislative Planning Updates page.
What state law changes mean
Washington State adopted new ADU laws that limit how cities can regulate ADUs, including caps on minimum allowed size and restrictions on parking and owner-occupancy requirements. If a local rule conflicts with state law, the state standard can apply. For context and updates, see the Washington State Department of Commerce ADU guidance. Because Anacortes has been updating its code, check the city’s ADU chapter before you finalize your design.
Before you design: quick checks
Start with a short due-diligence pass to avoid expensive surprises.
- Zoning, overlays, and maps. Confirm your zoning and whether your lot sits inside any overlay district or mapped constraint. Use the city’s maps and plan library on the City Codes and Guiding Plans page.
- Sewer vs. septic. If you are not on city sewer, Skagit County on-site sewage rules apply. Septic capacity can make or break an ADU. Review requirements and consider an inspection through the Skagit County On-Site Sewage Program.
- Critical areas. Wetlands, shorelines, steep slopes, and flood areas trigger extra studies and mitigation. The city provides mapping and forms through the City Codes and Guiding Plans page.
- Historic context. Properties in Old Town or on the local register may have added review and design expectations. Build extra time into your plan if this applies.
- Utility capacity. Older homes often need electrical panel upgrades and water or sewer connection changes. Utility fees are guided by city code, including ERU calculations and connection rules in AMC 13.08.020.
Your step-by-step permit path
Here is a simple, proven pathway to keep your submittal clean and review times shorter.
Pre-check with the city. Review the ADU code, maps, and any overlays. If questions arise, contact the city permit team and ask about pre-application guidance. The city’s SmartGov portal and forms are on the Permit Applications and Documents page.
Site assessment and concept design. Confirm sewer or septic approach, basic site grading and stormwater needs, and any critical areas. Sketch a concept plan and confirm likely utility upgrades and meter needs.
Prepare submittals. You will typically upload a site plan, building plans, stormwater documentation, and any required reports through SmartGov. Follow the city’s electronic submittal standards on the Permit Applications and Documents page.
Reviews you should expect. Planning checks land use and ADU standards. Building reviews structure and energy code. Public Works reviews utilities, driveway, and any right-of-way work. Critical areas or historic reviews may apply based on location.
Electrical permits and inspections. In Washington, electrical permits and inspections are handled by the Department of Labor & Industries, not the city. Plan your schedule around that separate process and see the city’s guidance under Do I Need a Permit.
Inspections and final occupancy. After passing building, mechanical, plumbing, and electrical inspections and completing any utility work, the city issues a certificate of occupancy.
Costs and timeline
Every site and design is different, but it helps to budget with realistic ranges.
- Construction ranges. Market guides show that interior or garage conversions can run from tens of thousands into the low six figures, while new detached ADUs commonly range from about $150,000 to $400,000 or more depending on size, finishes, and site work. Treat these as planning estimates only and validate with local quotes. See a national overview of ranges from HomeGuide’s ADU cost guide.
- Utility and fee impacts. General Facility Charges and ERU-based sewer and water fees can add thousands of dollars, especially for a new detached unit. Review utility rules in AMC 13.08.020 and get quotes early.
- Typical timing. Plan for a few weeks of site checks, 1 to 3 months for design, and a variable permit review that can extend with stormwater, septic, or critical-area studies. The city uses SmartGov for electronic submittals, which helps, but completeness is key. See current submittal standards on the Permit Applications and Documents page.
Common missteps to avoid
- Skipping a septic inspection or assuming your system can handle another dwelling. This is a top reason for denials and major cost changes. Use the Skagit County On-Site Sewage Program early.
- Relying on old rules. The city has been updating ADU standards, and state law has changed. Confirm the latest text in the ADU chapter of the municipal code before finalizing plans.
- Ignoring stormwater. Most projects need a basic stormwater plan and may need sizing or infiltration measures. Address this in your site plan and submittal package.
- Expecting instant approvals. Incomplete plans, missing reports, or overlooked overlays increase review cycles. Use the city’s SmartGov checklists on the Permit Applications and Documents page.
- Misrouting electrical permits. Electrical permits and inspections are through L&I. See Do I Need a Permit for direction.
Short-term rental rules
If your plan includes short-term rental income, pause and verify what is allowed. Anacortes limits short-term rentals in certain zones, and state law lets cities restrict STR use of ADUs. Review the city’s short-term rental code and confirm business licensing requirements before you bank on nightly rental income.
Quick start checklist
- Confirm zoning, overlays, and whether you are on city sewer using the City Codes and Guiding Plans page.
- If on septic, schedule an inspection and feasibility review with the Skagit County On-Site Sewage Program.
- Verify current ADU standards in the Anacortes Municipal Code and note the owner-occupancy change on the Legislative Planning Updates page.
- Scope utilities early and review potential fees in AMC 13.08.020.
- Prepare a complete SmartGov submittal using the Permit Applications and Documents page.
Ready to explore your options?
Whether you are planning a conversion or a new backyard cottage, having a clear ADU plan protects your timeline and budget. If you want a local perspective on lot selection, resale impacts, or rental positioning, reach out to Kate Fadden. You will get straight answers, local context, and a step-by-step plan that aligns with your goals.
FAQs
What are the current ADU size and parking rules in Anacortes?
- The city’s ADU chapter lists a 900 square foot maximum and off-street parking standards that can require up to three spaces unless on-street parking abuts the property; always confirm current language in the Anacortes Municipal Code.
How do Washington’s ADU laws affect my Anacortes project?
- State ADU laws limit how cities regulate ADU size, parking, and owner-occupancy; review the Department of Commerce ADU guidance and then verify the latest Anacortes code before final design.
How do I submit an ADU permit in Anacortes?
- Apply through the city’s SmartGov system and include plans, a site plan, stormwater documentation, and any required studies; see forms and standards on the Permit Applications and Documents page.
What if my property uses a septic system instead of city sewer?
- Septic capacity and condition can limit or add cost to an ADU; contact the Skagit County On-Site Sewage Program to evaluate feasibility early.
Who handles electrical permits and inspections for ADUs in Washington?
- Electrical permits and inspections are issued by Washington Labor & Industries, not the city; see the city’s guidance under Do I Need a Permit.
Can I use an ADU as a short-term rental in Anacortes?
- Short-term rentals are limited in certain zones and may not be allowed for ADUs; review the city’s short-term rental code and confirm licensing before planning for nightly rentals.
