What happens if you skip the permit (and you needed one)
- Stop-work orders plus a $500–$1,500 citation; if the unpermitted ADU is occupied, the city can post it as 'unfit for habitation' and levy fines of $100–$300 per day until corrected.
- Insurance denial: if your homeowner's policy learns of an unpermitted ADU before claim time, they can deny coverage for damage to the structure and any liability claim tied to occupancy.
- Resale Title Issue: real-estate disclosure laws (WA RCW 64.06) require the seller to disclose unpermitted work; this tanks appraisals ($20,000–$50,000 hit) and kills many loan offers.
- Refinance / Home Equity Loan Blocked: lenders run title searches and order appraisals; unpermitted ADUs trigger appraisal reduction, and the loan is denied until the ADU is permitted or removed ($5,000–$15,000 in legal + re-permitting costs).
Shoreline ADU permits — the key details
Shoreline Code 20.60 (effective 2023) governs ADUs in the city. The headline: Shoreline allows detached ADUs on ANY single-family residential lot, up to 800 sq ft, with NO owner-occupancy requirement (state law stripped that). That's the biggest city-unique carve: older Puget Sound cities like Shoreline had to rewrite their codes to comply with RCW 36.70A.697, which forbids owner-occupancy rules for detached ADUs. The code defines three ADU types: (1) detached ADU (new or conversion), (2) junior ADU (max 600 sq ft, must be interior to main house, no additional kitchen), and (3) ADU above garage. All three need a permit. Setbacks are 5 feet from rear property line for detached ADUs (vs. 20 feet for main houses) and 10 feet from side property lines — tight, but workable on Shoreline's typical 50-foot-wide lots. Height is limited to 25 feet (matching main-house rules). If your detached ADU is within a quarter-mile of a fixed-route bus stop (the Route 236 counts), parking is NOT required; otherwise, one space is required (but can be in a tandem arrangement).
The permit application requires a plot plan (showing setbacks, utility lines, trees over 6 inches diameter), floor plans, elevation drawings, foundation details if detached, and a parking plan (even if the plan just says 'none required per transit proximity waiver'). If your ADU has a separate utility connection (gas, electric, sewer), you must show that on the mechanical plan — Shoreline Building Department often requires a separate meter for electric and a dedicated sewer line (not shared with the main house). If you're sharing a sewer line, a trunk study or easement agreement is needed. This is standard across Puget Sound, but Shoreline's standard checklist explicitly calls it out because glacial-till soil (common in Shoreline) can cause settling and sewer-line stress. Plan review runs 20–30 days for single-family ADUs under the fast-track process; if you miss details or the site plan shows setback violations, it kicks to full review (40–60 days). The city allows resubmission of corrected plans electronically via eScan portal.
Zoning overlays in Shoreline can complicate ADUs: if your property is in the Interurban Trail Corridor overlay or within 100 feet of a critical area (streams, wetlands, geologically hazardous slopes — Shoreline has significant wetland protection), additional setbacks or studies may apply. The Puget Sound lowland is riddled with historical wetlands and seepage areas from glacial melt; the city's Critical Areas Ordinance (20.86.010) can push detached ADUs further back if drainage or wetland buffers are triggered. Request a 'Critical Areas Report' when you contact the city — $200–$500, and it clarifies whether a wetland buffer exemption or mitigation plan is needed. Shoreline's lot sizes (0.25–0.5 acres typical in residential neighborhoods) are usually big enough for a detached ADU PLUS a buffer, but corner lots or narrow properties can hit snags. If you're in the Aurora Avenue or Interurban Trail neighborhood overlay zones, design standards (roof pitch, material compatibility) apply — not a dealbreaker, but adds review cycles if the design doesn't echo the surrounding houses.
Parking is the second major local wild card. Within a quarter-mile of Route 236 (the main north-south transit corridor running through Shoreline), parking is waived. Outside that zone, you need one dedicated space. That space can be in the driveway, and it can be tandem (one behind the other with the main-house space) — Shoreline allows this on single-family lots. If your lot is tight and the detached ADU site eats the driveway, you may need to petition for a tandem parking variance or a 'small lot' waiver. The city has an online map tool (on the Shoreline city website) showing transit-proximity boundaries; confirm your address before finalizing the ADU location. Parking disputes are THE most common ADU rejection reason in Shoreline, so get clarity early.
Owner-builder status: Washington State law allows an owner-builder to pull permits for an ADU on their own property if they live there. Shoreline honors this, but you must sign the owner-builder declaration on the permit application and be on the property deed. If you hire a contractor, they pull the permit in their name (or you hire them as the permit applicant), and you're responsible for inspections. The city requires all framing, electrical, plumbing, and mechanical work to pass rough inspections before covering — standard stuff, but Shoreline's Building Department is strict about inspection scheduling (book 2–3 weeks in advance; late no-shows result in another inspection fee of $150–$300). Plan for 12–16 weeks from permit issuance to final approval if you DIY; 14–18 weeks if a contractor is managing. Final inspection includes a planning staff sign-off (use check) and a utility company verification of separate meter/service.
Three Shoreline accessory dwelling unit (adu) scenarios
Washington State Law Overrides — Why Your ADU Rights Are Broader Than Shoreline's Code Text Says
In 2023–2024, Washington updated RCW 36.70A.697 and 36.70A.698 to prohibit local jurisdictions from requiring owner-occupancy, limiting ADU size, or charging impact fees on ADUs. Shoreline's code (Title 20.60) had to fall in line. This means: even though the OLD Shoreline code (pre-2023) had an owner-occupancy requirement, that rule is now void. You can build a detached ADU, rent it out, and live in the main house — state law overrides the old local rule. Shoreline's current code reflects this, but some older planning documents or staff emails may still reference the old rules. If a permit reviewer mentions owner-occupancy, cite RCW 36.70A.697(2)(a) directly: 'A city or county shall not impose any of the following restrictions on accessory dwelling units: (a) A requirement that the owner of the property be an occupant of either the principal residential unit or the accessory dwelling unit.' This is your shield.
Impact fees are also prohibited for ADUs under RCW 36.70A.698. Shoreline cannot charge a water/sewer impact fee, roads impact fee, or school impact fee for an ADU. The city CAN charge a building permit fee (cost-of-service for plan review, inspection, enforcement) and a planning fee (for any conditional use process). The distinction: permit fees (let's say $500–$800 for an ADU permit) are recoverable because they cover staff time; impact fees (which might be $3,000–$5,000 for a detached dwelling in some jurisdictions) are not. When you get the permit cost estimate, ask Shoreline Building Department to itemize it: 'Permit Application' (cost-of-service, allowed), 'Plan Review' (allowed), vs. 'Water System Impact Fee' or 'Schools Impact Fee' (these should NOT appear on an ADU bill).
One loophole: the ADU must be on a lot with an existing or proposed principal residential unit (a single-family home or allowed housing type). You cannot build an ADU on a vacant lot or a commercial lot. Shoreline's code allows ADUs on single-family residential zoned parcels ONLY. If your property is zoned multi-family or commercial, ADU rules do not apply (it's not a legal ADU context).
Shoreline's Permit Portal and Fast-Track Process — How to Speed Things Up
Shoreline's Building Department uses the eScan online portal (accessible via the city website at www.shorelinewa.gov). You can create an account, upload documents, and track your permit status in real time. The portal is NOT just for viewing — it's your primary filing method. Paper submissions are still accepted but add 3–5 days to processing time. For ADUs, Shoreline offers a 'Fast-Track Plan Review' for projects that meet specific criteria: complete plot plan (to scale, with survey data or clear measurements), floor plans with dimensions, foundation details if detached, electrical/plumbing schematics, and design statement if in an overlay zone. If all required items are submitted at once, the initial plan review is guaranteed within 20 days. If documents are missing, plan review restarts, so completeness is critical. Before uploading, download the 'ADU Checklist' from the Shoreline Building Department website — it lists every required document and typical reasons for rejection (setback errors, parking not addressed, egress windows not shown, utility connections vague).
Inspection scheduling via the portal: once the permit is issued, you request inspections online. Shoreline Building Department schedules them within 10 business days. The city is strict about no-shows (if you miss an inspection appointment, you'll be charged a $200–$300 re-inspection fee). Plan your construction schedule to avoid missed windows — notify the inspector 24 hours in advance if you need to reschedule. Standard ADU inspection sequence: (1) foundation (before footing pour), (2) framing & roof (before drywall), (3) rough mechanical/electrical/plumbing (before walls are closed), (4) insulation (before drywall), (5) drywall, (6) final + utility sign-off. Expect 6–8 inspections total.
Cost-saving tip: owner-builders can pull their own permits and perform DIY work on owner-occupied properties in Washington. You sign the owner-builder declaration (you're responsible for code compliance), and then you can hire subcontractors for specific trades (framing, electrical, plumbing) or do it yourself if you're qualified. Shoreline doesn't require a general contractor license for ADU owner-builders, but individual trades (electrical, plumbing) still need to be done by licensed electricians/plumbers in Washington State (RCW 19.28.005 for electrical; RCW 18.106.030 for plumbing). If you hire a contractor to do the full build, they pull the permit and manage inspections — you pay them for this overhead (typically $2,000–$5,000 extra on the project cost as permit & plan review management fees).
17500 Midvale Avenue N, Shoreline, WA 98133 (Shoreline City Hall — Building Services Division on 1st floor)
Phone: (206) 546-1700 (main) — Building Department ext. 5600 | https://www.shorelinewa.gov/government/departments/planning-development-services/building-permit-applications
Monday–Friday, 8:00 AM–5:00 PM (closed weekends and city holidays)
Common questions
Does my ADU need a separate utility meter in Shoreline?
Yes, for electrical: Shoreline requires a separate electrical meter or sub-panel for any ADU (detached, junior, or above-garage). For sewer, a separate lateral is strongly preferred; if you share a sewer line with the main house, you'll need a trunk study or easement agreement confirming the shared connection is legal and adequate for two units. Water meters: both the main house and ADU can be on one meter (the city allows this), but electrical MUST be separate for utility tracking and occupancy verification. Confirm with Shoreline Building Department at plan review which utilities require separate service in your specific case.
Can I build a detached ADU if my lot is only 0.25 acres?
Likely yes, but not guaranteed. Shoreline Code 20.60.020 allows detached ADUs on single-family lots with NO minimum lot-size requirement — that's the state-law mandate. However, setback rules (5 feet rear, 10 feet side), parking (if outside transit zone), and critical-area buffers may make a detached ADU infeasible on a very small or narrow lot. A 0.25-acre lot is roughly 105 x 105 feet; if you place a 20x30 detached ADU (600 sq ft) with 5-foot rear and 10-foot side setbacks, you'll need at least 30 feet deep and 50 feet wide clear area. Most 0.25-acre Shoreline lots CAN fit this, but corners, slopes, trees, or wetlands can block it. Submit a preliminary plot plan to Shoreline Building Department (no fee, just an email) — they'll do a quick feasibility check.
What's the difference between a junior ADU and a standard ADU in Shoreline, and does it affect the permit?
A junior ADU in Shoreline Code 20.60.030(b) is max 600 sq ft, must be interior to the main structure (no detached junior ADUs), and has NO full kitchen (kitchenette only — sink, microwave, mini fridge, but no range/oven). It does NOT require a separate entrance. A standard ADU can be detached, up to 800 sq ft, with a full kitchen, and requires a separate entrance. Both need permits, but junior ADUs have a simpler plan-review process (fewer inspections, no cooking-appliance gas lines, smaller footprint). Permit fees are lower for juniors ($250–$400 vs. $400–$600 for standard ADUs). If you're converting a garage, a junior ADU is often the faster, cheaper path. If you're building new detached, a standard ADU gives you more flexibility.
Does my ADU need a septic system, or is it connected to city sewer?
Shoreline is entirely within the city sewer service area — there are NO septic systems in Shoreline proper. Your ADU must connect to the city sewer line (usually a main in the street or an alley). If the main is far from your property (rare but possible in the Edmonds-Shoreline border areas), you may need a sewer pump or lift station (cost $5,000–$10,000 extra). Confirm with Shoreline Public Works (Water & Wastewater) that your property is in the service area before designing the sewer lateral. A sewer availability letter costs $100–$200 and is often required at permit application.
If I'm within the Route 236 transit zone, how do I prove it to avoid the parking requirement?
Shoreline has an online mapping tool on the city website (Planning & Development Services page) that shows the quarter-mile transit buffer around Route 236. Search your address in the tool, and it will confirm 'Yes, in transit zone — parking waived' or 'No, parking required.' Take a screenshot and include it with your permit application. Shoreline Building Department reviews it automatically. If the tool shows you're OUT of the zone but you believe you're within 0.25 miles of the bus stop, you can request a manual verification (measure the distance from your property to the nearest Route 236 stop) — the city will issue a written waiver. This costs $150–$300 and takes 1–2 weeks.
What if my property is near a wetland or stream? Does that stop the ADU?
Not necessarily, but it complicates the permit. Shoreline's Critical Areas Ordinance (20.86) creates buffers around wetlands (25–50 feet depending on wetland size/type) and streams (25 feet minimum). If your ADU site is OUTSIDE the buffer, no issue. If the ADU is inside the buffer, you need a Conditional Use Permit (CUP) from the Planning Division, which requires a wetland report, mitigation plan, and public hearing (6–10 weeks). This adds $1,500–$3,000 in CUP fees and $800–$1,500 for the wetland study. Before committing to an ADU location, request a Critical Areas map from the city (free, online) or a verbal confirmation. Avoid placing a detached ADU in a buffer zone unless you're prepared for the CUP process.
Can I get an ADU permit if I don't own the property outright (e.g., I have a mortgage)?
Yes. You do NOT need to own the property free and clear to pull an ADU permit. The lender may have restrictions (some mortgages prohibit rental ADUs), but that's a loan agreement issue, not a permit issue. Shoreline Building Department does NOT require proof of ownership before issuing a permit — you just sign the application declaring you're authorized to do the work (owner, owner-builder, or licensed contractor). If you're the owner-builder, you'll sign the owner-builder declaration. If you hire a contractor, they'll be the permit applicant. Recommend checking with your lender BEFORE starting design and permitting — some lenders will require the ADU to be owner-occupied or will adjust your loan terms if you're renting it out. This doesn't affect the permit, but it affects your financing.
How long does Shoreline take to issue a permit from application to approval?
For a complete ADU application (all required documents submitted at once), plan review is 20–30 days under the fast-track process. If documents are incomplete, the review clock restarts after resubmission (another 20–30 days). After the permit is issued, construction and inspections typically take 8–16 weeks depending on whether you hire a contractor or DIY. Total elapsed time: 4–6 weeks for plan review, 8–16 weeks for construction, 1–2 weeks for final sign-off = 13–24 weeks (3–6 months) from application to occupancy. If your project requires a Critical Areas CUP (wetland, stream buffer), add 6–10 weeks to the front end. Budget 6 months conservatively if critical areas are involved; 3–4 months for straightforward ADUs outside overlays.
What happens at final inspection? Does the city verify occupancy or rental status?
At final inspection, Shoreline Building Department verifies that the ADU is constructed to code (electrical, plumbing, egress, egress windows, foundation, etc.). They do NOT inspect for occupancy status or rental agreements. The ADU does NOT need to be 'owner-occupied' under current state law (RCW 36.70A.697 struck that requirement). You can rent it out immediately after final approval, or leave it vacant. The city does not monitor who lives there. However, if a neighbor complains about unpermitted occupancy later, or if an ADU is being used for short-term rentals (Airbnb, VRBO) without a license, that's an enforcement issue separate from the building permit. Shoreline's Planning Division can cite short-term rental violations (STRs require a specific land-use license), but the building permit itself doesn't regulate rental status.
If I'm doing owner-builder work, do I need a contractor's license in Washington?
For general construction (framing, site prep, decking, etc.), NO — owner-builders in Washington do not need a license. For SPECIALIZED trades, YES: electrical work must be done by a licensed electrician (RCW 19.28.005) and plumbing by a licensed plumber (RCW 18.106.030). You can pull the ADU permit as an owner-builder (you sign the owner-builder declaration), but you must hire a licensed electrician for all electrical work (rough-in, sub-panel, meter connections) and a licensed plumber for all plumbing (rough-in, vents, cleanouts). Shoreline will not issue an electrical permit to an unlicensed owner-builder. HVAC, if you're installing it, also requires a state license (RCW 18.160). If you're using a heat pump or ductless mini-split for an ADU, hire a licensed HVAC contractor.