Qualifies to build one single-family residence (Island County permits a dwelling on a legal pre-existing lot even though it's under the current minimum). Realistically you can put up:A single-family home, up to 35 ft in heightAccessory buildings — detached garage, shop, shed Likely one ADU (Island County allows accessory dwelling units, size-capped) and/or a guest quartersHome occupation / typical rural accessory usesTypical Rural setbacks are roughly 20 ft front, 20 ft rear, and ~5–8 ft sides (exact figures in ICC 17.03.180.S — worth confirming for the final building envelope). The big advantages here:Community water is already available through Possession Shores Inc. — no well to drill, which is a major cost/risk saver on a rural lot.Flood Zone X (minimal hazard) — not in a special flood hazard area, so no flood-elevation construction or flood insurance requirement.No mapped wetlands on or adjacent to the lot. Two things to verify before counting on a build (the real gating items):Septic. Steep slope. The county's steep-slope (geologically hazardous) layer touches the parcel area. That can trim the buildable footprint and may trigger a geotech assessment. Also confirm whether any part falls within shoreline (200-ft) jurisdiction given the proximity to Possession Sound.