Do I need a permit in Arlington, Washington?
Arlington sits in Snohomish County between the Puget Sound lowlands and the Cascade foothills, which means your frost depth, soil type, and flood risk can shift dramatically within city limits. The City of Arlington Building Department administers permits under the 2021 Washington State Building Code, which incorporates the 2021 IBC with state amendments. The county's volcanic and glacial-till soils, combined with a 12-inch frost line on the west side and 30+ inches on the east, shape what's required for footings, drainage, and foundation work. Arlington also sits in a river corridor — the Stillaguamish River runs through town — which adds floodplain zoning to your decision tree for any project near the water. The city adopts state code with local amendments; those local rules are what catch most homeowners off guard, especially around setbacks, lot coverage, and critical areas like wetlands and steep slopes. A 90-second phone call to the Building Department before you break ground saves weeks of rework and fines.
What's specific to Arlington permits
Arlington requires a permit for nearly any structural work or improvement that alters the footprint, height, or use of your property. Decks over 30 inches high, additions of any size, carports, sheds over 200 square feet, and fences over 6 feet all trigger the permit process. The city has adopted critical areas regulations under the Growth Management Act; if your project touches a wetland, stream buffer, steep slope (over 15%), or landslide-hazard area, expect a critical areas study and possible environmental review before permits are issued. This is not negotiable and not fast — plan for 30–60 days minimum if critical areas are involved.
Arlington's online permit portal allows you to check the status of active permits and access some application forms, but over-the-counter submittals are still the norm for straightforward projects like single-family decks and fences. The Building Department is located in Arlington City Hall; you can call ahead to ask if your project qualifies for same-day or next-day review, or file by mail if you're not local. Turnaround for plan review on a standard deck or fence is 1–2 weeks if there are no comments; add time if the reviewer flags setback, height, or structural details.
Flood insurance requirements are stricter than they appear. If your property is in the mapped floodplain (check the FEMA Flood Insurance Rate Map or ask the city), any construction below the Base Flood Elevation (usually 10–15 feet above grade) requires floodproofing, elevated utilities, or flood vents. Many Arlington properties sit just outside the official floodplain but have a history of water intrusion; the city's floodplain manager can advise, but don't rely on 'I've never seen water here.' The Stillaguamish and Sultan rivers have wide, shallow floodplains that shift seasonally.
Setback rules are tight in Arlington's residential zones. Most single-family lots require 20 feet front, 10 feet side, and 20 feet rear — but corner lots, flag lots, and properties in the downtown urban zone have their own rules. Decks, carports, and accessory structures sometimes get relief under 'not counted toward setback' if they're under a certain size and meet specific conditions, but the default is that they do count. Measure before you design; a deck that violates setback by 1 foot is not buildable without a variance, which costs $500–$800 and takes 4–8 weeks.
Owner-builders are allowed for primary-residence projects, but you must live in the home and do the work yourself — or hire licensed contractors for trades that require licensing (electrical, plumbing, gas, HVAC). You'll need a homeowner exemption certificate from the Department of Labor and Industries before permits are issued. If you're acting as your own contractor, you're responsible for all subpermits, inspections, and code compliance; many owner-builders are surprised by the inspection schedule (rough framing, insulation, final) and the cost of bringing in licensed trades for systems work.
Most common Arlington permit projects
These are the projects that come through the Arlington Building Department most often. Each has its own quirks — setback issues, frost-depth footings, floodplain exposure — so read the specific guidance for yours.
Decks
Decks over 30 inches high or covering more than 200 square feet require a permit. Frost depth varies: 12 inches in the Puget Sound lowlands, 30+ inches east of the Cascades foothills. You'll need frost-protected footings, proper ledger bolting to the house rim, and often a survey showing setbacks on corner or irregular lots.
Fences
Fences over 6 feet require a permit; most residential fences in yards are exempt if under 6 feet. Property-line fences and walls enclosing pools or spas always need permits. If your lot is in a sight triangle (corner lot or lot at an intersection), height limits are stricter; ask the city before ordering materials.
Additions and room conversions
Any structural addition or finished basement conversion requires a full building permit. If your addition or conversion touches a critical area (wetland, stream, steep slope), add 4–6 weeks for environmental review. Single-story additions under 500 square feet often clear faster than two-story work.
Sheds and accessory structures
Sheds over 200 square feet, any detached garage, and carports require a permit. Structures under 200 square feet and not used for human occupancy may be exempt if they're accessory use and meet setback distance; check the zoning code or call ahead. Foundation, wind, and snow-load requirements apply statewide under the 2021 Building Code.
Roofing and re-roofing
Re-roofing (tear-off and replacement) typically requires a permit. Some jurisdictions exempt roof covering on existing structures if no structural work is done, but Arlington requires notification and an inspector walk-through to confirm no underlying damage or code violations. Get a roofing estimate and ask the city whether a full permit or an ROW (roof-over-wood) exemption applies.
Electrical and mechanical work
Electrical subpermits are required for new circuits, panel upgrades, sub-panels, and hot-tub wiring. Hot-tub installation also triggers a mechanical permit (spa/pool equipment). Hire a licensed electrician; they'll pull the subpermit. DIY electrical is not allowed even for owner-builders in Washington — the state requires a licensed electrician's signature on the permit.
Arlington Building Department contact
City of Arlington Building Department
Contact Arlington City Hall for address and mailing location
Call city hall or search 'Arlington WA building permit phone' for current number
Monday–Friday, 8 AM–5 PM (verify by calling ahead)
Online permit portal →
Washington state context for Arlington permits
Washington adopted the 2021 IBC as the foundation for the 2021 Washington State Building Code, with state-level amendments that tighten energy efficiency, seismic requirements, and owner-builder regulations. The state Department of Labor and Industries (L&I) oversees licensing and apprenticeship for electrical, plumbing, HVAC, and gas work; Arlington uses L&I licensing as the standard. Any contractor working on your project must carry a valid Washington Contractor's License from the Department of Revenue. Washington does not allow unlicensed individuals to do electrical work on residential projects, even owner-builders — you must hire a licensed electrician or sign up for the apprenticeship program and work under a licensed supervising electrician's direct oversight. Seismic requirements are significant; the 2021 code mandates water-heater strapping, gas-line flexibility, and foundation anchoring to resist earthquake movement. Frost-depth requirements are enforced statewide at 12 inches minimum (though Arlington's east side may require 30+), and floodplain construction follows FEMA guidelines with state amendments. Washington's Growth Management Act requires cities like Arlington to protect critical areas (wetlands, critical aquifer recharge areas, fish and wildlife habitat) through local regulations; any project within 200 feet of a wetland or stream may require a critical areas study, which adds cost and timeline.
Common questions
What's the fastest way to get a permit in Arlington?
Call the Building Department and describe your project before you design it. If it's straightforward (deck under 400 sq ft, no critical areas, no setback issues), ask if you can do an over-the-counter review. Bring your site plan, dimensions, and construction details. Simple permits can clear the same day or next day. If your lot touches a wetland, stream, or floodplain, expect 30–60 days minimum.
Do I need a permit for a single-story deck under 200 square feet?
If the deck is more than 30 inches above grade, yes, you need a permit — regardless of size. Arlington counts height, not size, as the trigger. A 12×16 deck (192 sq ft) that sits on a concrete pad 3 feet above finished grade needs a permit, frost-protected footings, guardrails, and an inspection. If your deck is attached to the house, you'll also need a proper ledger bolting detail (bolted to the rim board, not the rim joist).
What if my property is in the floodplain?
Check the FEMA Flood Insurance Rate Map or call the city's floodplain manager. If you're in the mapped floodplain, any work below the Base Flood Elevation (usually marked on the map or provided by the city) requires floodproofing, elevated utilities, and possibly flood vents. If you're above the elevation, you may not need floodproofing, but inform the city during permit review. Flood insurance is mandatory for federally financed mortgages in the floodplain, and fines for unpermitted work in the floodplain run 5,000–10,000 dollars.
Can I do electrical work myself if I own the house?
No. Washington state law requires all electrical work on residential properties to be performed by a licensed electrician, even if you're the owner-builder. You cannot pull an electrical subpermit yourself. Hire a licensed electrician; they'll file the subpermit, do the work, and request inspections. Unpermitted electrical work can void insurance, fail future sale inspections, and result in fines.
How much do permits cost in Arlington?
Building permit fees are based on the estimated project valuation and vary by permit type. A deck permit is typically $150–$400 depending on size and complexity. A fence permit is a flat fee (usually $75–$150). An addition or garage runs $300–$800 for plan review plus $0.50–$1.50 per square foot of construction. Call the Building Department with your project scope and square footage for a specific estimate. Subpermits (electrical, plumbing) are separate and charged by the licensed trade.
What's a critical areas study and how much does it cost?
If your property or project is within 200 feet of a mapped wetland, stream, or steep slope, the city requires an environmental assessment or critical areas report. A consultant (wetland specialist, environmental engineer, or geotechnical specialist) must prepare the study, which costs $1,500–$5,000+ depending on site size and complexity. The study determines setbacks, buffers, and mitigation conditions. This is separate from the building permit and can delay permitting by 6–12 weeks if mitigation is required.
Do I need a survey before I pull a permit?
Not always, but yes for corner lots, flag lots, or projects that might violate setbacks. If your deck, addition, or fence sits within 10 feet of a side property line or 20 feet of a front property line, the city will ask for setback confirmation — a sketch with measured offsets or a full survey. A rough sketch from you (with a tape measure) often suffices for simple projects; a professional survey costs $300–$600 but is required if setbacks are tight or disputed.
Can I act as my own general contractor and hire subs?
Yes, if you're the owner-builder on a primary residence. You must live in the home and own it. You'll need a homeowner exemption certificate from the Department of Labor and Industries (L&I) before permits are issued. You can hire licensed subcontractors for electrical, plumbing, HVAC, and other licensed trades. You're responsible for coordinating inspections, scheduling the work, and ensuring code compliance on the parts you do yourself (framing, drywall, trim, etc.). If the inspector finds unpermitted or non-compliant work, you're liable for fines and rework.
What happens if I build without a permit?
Arlington Building Inspections responds to complaints and random patrols in new construction areas. If unpermitted work is discovered, you'll be ordered to stop, get a permit, and pass inspections — or remove the work. Fines start at a few hundred dollars and escalate if work poses a safety risk (bad electrical, poor framing, structural defects). Unpermitted work also clouds the sale of the property; buyers' lenders and inspectors will flag it, and you may have to bring it up to code or discount the sale price. Unpermitted work in a critical area (wetland, floodplain) carries much stiffer penalties.
Ready to figure out your Arlington permit?
Start by calling the City of Arlington Building Department. Have your address, project type, and rough square footage ready. Most staff can give you a yes/no answer and a fee estimate in 5 minutes. If you need to file online or in person, bring your site plan, a sketch of what you're building, and dimensions. If critical areas or setbacks are a question, take photos of your lot and any nearby water or trees, and ask the city planner whether an environmental study is required before you hire a designer. Don't start work before you have a permit and an inspection schedule — it's the difference between a $300 permit and a $3,000 rework.