Off-grid site report

Multnomah County, OR

45.5267, -122.4058 · 331 ft elevation
Read this before you act on anything below. This is my researched starting point for Multnomah County, OR, not legal advice and not a guarantee. Rules change, and the deciding facts on any specific parcel (setbacks, perc results, overlay districts, deed restrictions, road frontage) live at the county or town office, not in any database. Before you buy land or build, confirm the current rules directly with the local zoning and health offices - the sources on this page tell you exactly who to call.

The local rulesMultnomah County, OR

Zoning & raw-land occupancy
Varies locallyMultnomah County zoning code sets rural district minimum lot sizes (MUA-20 = 20 acres, RR = 5 acres, RC = 1 acre, MUF varies) for unincorporated land; incorporated cities like Portland, Gresham, Troutdale, Fairview and Maywood Park apply their own separate zoning instead. source
Dwellings, tiny homes & RVs
RestrictedRural manufactured/mobile dwellings must meet Oregon building code and mobile-home statutes, sit on a permitted foundation, and meet a minimum floor area; RVs and tiny-houses-on-wheels are treated as temporary/accessory, not standalone residences, on undeveloped land per Portland's code. Not confirmed whether Multnomah County has opted into Oregon's SB 1013 RV-dwelling program. source
Building permits & codes
RestrictedMultnomah County Land Use Planning issues permits/approvals for unincorporated land, requiring an approved foundation and issued septic authorization before occupancy; incorporated cities issue their own building permits. source
Septic & composting toilets
Generally allowedPortland Permitting & Development administers septic permitting and inspections for the entire county, including unincorporated areas and every incorporated city within it, under an intergovernmental agreement with the county and Oregon DEQ. source
Greywater reuse
Unclear - verifyNo county-specific greywater ordinance was found; Oregon DEQ's statewide tiered greywater permit program appears to apply by default. Not confirmed whether the county adds requirements beyond the state program, so ask Portland's septic program or the county.
Rainwater harvesting
Unclear - verifyNo Multnomah County-specific rainwater ordinance was located; Oregon's statewide exemption for roof/impervious-surface catchment appears to govern, subject to any local plumbing code hookup rules. Confirm specifics with the county or relevant city building department.
Private wells & water rights
Generally allowedWell construction, domestic-use exemptions, and well logs are handled statewide by the Oregon Water Resources Department; no distinct Multnomah County well ordinance was found. The county's Water Quality Program offers related drinking-water resources. source
Living disconnected from utilities
Generally allowedLiving off-grid from electric or municipal water isn't itself prohibited, but final building permit approval in unincorporated Multnomah County requires an issued septic authorization or installation permit as part of the process. source

Open the full county page with sources →

Sun30-year normals

Peak-sun hours, annual average
3.9 hrs/day
Worst month (sizes an off-grid array)
1.6 hrs/day
Yearly output per 1 kW of panels
1,081 kWh
JFMAMJJASOND

Weather1991-2020

Precipitation
47 in/yr
Snowfall
2 in/yr
Heating degree days
4,641 (moderate)

How far help isstraight-line

Hospital
none within range
Fire station
Gresham Fire Station 71
2.0 mi
Hardware store
Harbor Freight Tools
0.7 mi
Grocery
Safeway
0.5 mi

From OpenStreetMap. Road miles will be longer, often much longer in hill country.

Plan this spot

These open with this location's real numbers already filled in (ZIP 97030).

Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt

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Sources: US Census Bureau geocoder; NLR PVWatts v8 (solar); NOAA NCEI 1991-2020 climate normals (nearest station) or Open-Meteo (ZIP-centroid) for weather; Open-Elevation; OpenStreetMap contributors. Public data retrieved Aug 21, 2026; agencies update their layers on their own schedules. Planning data, not a survey or legal advice.