Zoning Report

Portland, OR Zoning

Portland, Oregon has a layered zoning system built around base zones, overlay zones, plan districts, and additional use and development regulations. The city’s zoning code emphasizes that a property may be subject to all of these layers at once, with plan districts and overlays able to override base-zone standards where they conflict. Public information provided by the city highlights a broad range of residential, mixed-use, commercial, employment, industrial, and institutional zones, plus specialized review pathways for design, historic, environmental, floodplain, and other constrained sites.

Last researched May 2026

base zonesoverlay zonesADUsnonconforming situationsfloodplain constraintsland use review appealspermit reviewdesign overlayhistoric overlayenvironmental overlaygreenway and river overlays

Zoning Districts in Portland, OR

Single-Dwelling Residential Zones (RF, R20, R10, R7, R5, R2.5)

These are Portland’s lower-density residential base zones for house-scaled neighborhoods. They regulate where houses and related residential forms are allowed and apply zone-specific development standards such as height, setbacks, and minimum lot area.

Allowed uses: Houses, Accessory dwelling units (subject to Chapter 33.205), Some duplex-related ADU configurations in R20 through R2.5, subject to standards

Multi-Dwelling Zones (RM1, RM2, RM3, RM4, RX, RMP)

These are Portland’s higher-density residential zones intended for multi-dwelling housing forms. They have their own use permissions and development standards and can also accommodate ADUs in some situations.

Allowed uses: Multi-dwelling residential uses, Accessory dwelling units in applicable situations

Commercial / Mixed Use Zones (CR, CM1, CM2, CM3, CE, CX)

These zones are intended for commercial activity, mixed-use development, and in some cases residential uses. Portland’s materials note that allowed uses must be checked by use category and may be modified by overlays or additional regulations.

Allowed uses: Commercial uses by use category, Mixed-use development, Some residential and ADU-related configurations in applicable zones

Employment and Industrial Zones (EG1, EG2, EX, IG1, IG2, IH)

These zones are intended for employment, industrial, and related commercial activities. The EX zone is specifically referenced in the city’s ADU guidance as allowing detached ADUs in some circumstances.

Allowed uses: Employment uses, Industrial uses, Detached ADUs in EX, per city ADU guidance

Campus Institutional Zones (IR, CI1, CI2)

These zones are used for campus and institutional areas with specialized zoning standards. The city treats them as a distinct base-zone category.

Allowed uses: Institutional and campus-related uses

Recent Zoning Changes

Portland has been advancing Regulatory Improvement Code Amendment Package 11 (RICAP 11), a citywide code maintenance package focused on parking, exterior site areas, and regulatory reduction. The ordinance text provided states that City Council directed amendments to Titles 32 and 33 using the May 2026 Recommended Draft; based on the supplied excerpt, the package appears to have reached Council action in 2026, though the exact final effective date was not provided in the research.

Setbacks, Lot Size & Height Limits in Portland, OR

The supplied sources confirm that Portland’s development standards are zone-based and may include maximum height, setbacks, lot area, density, and FAR. The clearest numerical standards in the research set are the ADU-related minimum lot areas in single-dwelling zones. A full citywide dimensional table for each base zone was not included in the supplied materials.

District	Standard	Requirement
R20	Minimum lot area for one ADU on a lot with a primary structure	10,000 sq. ft. — From the city ADU guidance for RF through R2.5 zones.
R10	Minimum lot area for one ADU on a lot with a primary structure	5,000 sq. ft. — From the city ADU guidance for RF through R2.5 zones.
R7	Minimum lot area for one ADU on a lot with a primary structure	3,500 sq. ft. — From the city ADU guidance for RF through R2.5 zones.
R5	Minimum lot area for one ADU on a lot with a primary structure	2,500 sq. ft. — From the city ADU guidance for RF through R2.5 zones.
R2.5	Minimum lot area for one ADU on a lot with a primary structure	1,500 sq. ft. — From the city ADU guidance for RF through R2.5 zones.
R20	Minimum lot area for one ADU with an attached house	12,000 sq. ft. — From Table 205-1 cited in the city ADU guidance.
R10	Minimum lot area for one ADU with an attached house	6,000 sq. ft. — From Table 205-1 cited in the city ADU guidance.
R7	Minimum lot area for one ADU with an attached house	4,200 sq. ft. — From Table 205-1 cited in the city ADU guidance.
R5	Minimum lot area for one ADU with an attached house	3,000 sq. ft. — From Table 205-1 cited in the city ADU guidance.
R2.5	Minimum lot area for one ADU with an attached house	1,500 sq. ft. — From Table 205-1 cited in the city ADU guidance.

ADU, Rental & Special Use Rules in Portland, OR

ADU

An accessory dwelling unit is a smaller home on the same lot as the main one and must contain independent living facilities for living, cooking, eating, sleeping, and sanitation. ADUs may be created by internal conversion, addition, conversion of an accessory structure, or new detached construction.

Allowed as accessory to a house
May be located within a house
May be proposed as a manufactured home
Detached and accessory to a duplex in applicable circumstances
Detached ADUs are allowed in residential, multi-dwelling, commercial, and EX zones subject to Chapter 33.205

Overlay Districts in Portland, OR

Buffer Zone

Requires additional buffering between nonresidential and residential zones.

Design Overlay Zone

Applied where design and neighborhood character are of special concern.

Environmental Zone

Requires protection of resources and functional values identified by the city as benefiting the public.

Future Urban Zone

Limits development in future urban areas.

River Overlay Zones

Generally promote protection, conservation, restoration, enhancement, and maintenance of economic, natural, scenic, and recreational qualities along the central reach of the Willamette River.

Greenway Overlay Zones

Affect some property along the Willamette River.

Aircraft Landing Zone

Limits the height of structures and vegetation near Portland International Airport.

Historic Resource Protection Overlay Zone

Protects certain historic landmarks, conservation landmarks, and resources in historic or conservation districts.

Portland, OR Zoning FAQ

Are ADUs allowed in Portland, OR?

What is the minimum lot size in Portland, OR?

Minimum lot size depends on the zoning district — R20: 10,000 sq. ft.; R10: 5,000 sq. ft.; R7: 3,500 sq. ft.; R5: 2,500 sq. ft..

What zoning districts are in Portland, OR?

Portland, OR includes districts such as Single-Dwelling Residential Zones (RF, R20, R10, R7, R5, R2.5), Multi-Dwelling Zones (RM1, RM2, RM3, RM4, RX, RMP), Commercial / Mixed Use Zones (CR, CM1, CM2, CM3, CE, CX), Employment and Industrial Zones (EG1, EG2, EX, IG1, IG2, IH), Campus Institutional Zones (IR, CI1, CI2).

Are there flood zones or overlay districts in Portland, OR?

Environmental and hazard constraints are an important part of Portland development review. The city flags floodplains, environmental overlay zones, and river-related overlay zones as complex sites that require more detailed submittals, and several overlays protect natural resources, river corridors, scenic resources, a…

Have there been recent zoning changes in Portland, OR?

Portland has been advancing Regulatory Improvement Code Amendment Package 11 (RICAP 11), a citywide code maintenance package focused on parking, exterior site areas, and regulatory reduction.

Common questions about Portland, OR zoning

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Sources

Drawing a site plan | Portland.gov — Provided building-permit site-plan requirements, right-of-way dedication/improvement notes, and identified floodplain, environmental, and river-related sites as complex sites requiring more information.
Microsoft Word - 258-ncu — Primary source for Portland’s nonconforming use and development rules, legal status, and evidentiary requirements.
Base Zones | Portland.gov — Provided overview of Portland base-zone categories, general use-permission framework, and development-standard concepts.
Accessory dwelling unit (ADU) zoning requirements | Portland.gov — Primary source for ADU definitions, eligible zones, minimum lot areas, and duplex-related ADU conditions.
Permit Review and Getting Your Permit | Portland.gov — Provided building permit submission, electronic plan review, checksheet, and status-tracking process information.
Land Use Review Appeals | Portland.gov — Primary source for local appeal procedures, hearing bodies, deadlines, and LUBA appeal pathways.
Amend City Code and improve land use regulations through the Regulatory Improvement Code Amendment Package 11 (amend Code Titles 32 and 33) | Portland.gov — Provided recent legislative zoning activity, hearing dates, Planning Commission actions, and Council direction on RICAP 11.
Overlay Zones | Portland.gov — Primary source for identifying Portland overlay zones and their general purpose and effect.
Overview of the Zoning Code | Portland.gov — Provided the overall zoning hierarchy, relationship between base zones, overlays, plan districts, and administration structure.
Flood Hazard Regulations and Flood Maps | Portland.gov — Provided flood hazard mapping references and confirmed the city maintains floodplain mapping resources tied to flood regulations.
24.50.070 Appeals and Variances. | Portland.gov — Provided current floodplain appeal and variance criteria, including the rarity and limits of flood variances.
[PDF] Nonconforming Upgrades Overview | Portland.gov — Explained upgrade triggers and options for existing nonconforming site features such as landscaping, bicycle parking, screening, paving, and pedestrian circulation.

This summary is AI-generated from public municipal sources and is not legal, engineering, or land-use advice. Always verify zoning with Portland, OR officials before making decisions.