ADU feasibility on your lot
ADU forum questions almost always start with “Can I build on my lot?” The answer depends on zoning, setbacks, utilities, and access — not on how much space you want inside.
Washington homeowners increasingly explore backyard cottages and in-law units. Online ADU groups repeat the same feasibility checklist: buildable envelope after setbacks, height limits, lot coverage, utility capacity, fire separation from the main house, and whether an HOA or design review layer applies.
A site survey is worth the cost before you invest in full architectural drawings. Guessing setback lines from fence lines leads to redesigns. Septic capacity, sewer tie-in location, and electrical panel headroom matter as much as square footage.
Detached ADUs, garage conversions, and attached units each carry different tradeoffs for privacy, utility runs, and code paths. Forum advice that worked in Seattle may not match unincorporated Snohomish County rules — confirm jurisdiction from your address first.
Talk to your jurisdiction early about driveway access, fire lane width, and tree protection if applicable. Those items rarely show up on Pinterest floor plans but can shrink the buildable pad significantly.
Feasibility check path
-
1
Confirm jurisdiction City vs. county rules; start with your parcel address.
-
2
Review survey & envelope Setbacks, easements, slopes, and buildable area.
-
3
Assess utilities Water, sewer/septic, gas, electrical capacity for a second unit.
-
4
Concept footprint Detached, conversion, or attached — each has different constraints.
Artbrick supports permit applications and coordinates with your jurisdiction. We do not guarantee approval or approval timelines — those are set by the authority having jurisdiction.
