Portland, OR Zoning
Districts & Requirements
Every zoning district in Portland with permitted uses, setbacks, height limits, and density requirements — in plain English. Portland's zoning code (Title 33) was reshaped by Oregon's HB 2001 (2019) and the city's Residential Infill Project (RIP, 2020). Duplexes, triplexes, and fourplexes are now allowed on virtually every residential lot. Six units are possible with an affordability covenant. The commercial/mixed-use zones (CM1-CM3, CE, CX) offer FAR and height bonuses for inclusionary housing. Portland's Inclusionary Housing mandate applies to projects of 20+ units.
18
Zoning districts
8
Overlay districts
652,000
Population
2024
Code adopted
Quick Reference
Find your district, see what you can do. Click any row for details.
| District | At a glance | Height | Coverage |
|---|---|---|---|
| R5 | Standard single-family lots. Fourplexes by right under RIP. 0.5 FAR base, 0.7 with 3+ units. | 30 ft | Controlled by FAR and setbacks |
| R7 | Mid-size lots, 7,000 SF. Fourplexes allowed. Lower FAR (0.4) limits building size vs R5. | 30 ft | Controlled by FAR and setbacks |
| R2.5 | Narrow-lot infill. 1,500 SF minimum. Fourplexes allowed. Highest by-right density in single-dwelling zones. | 35 ft | Controlled by FAR and setbacks |
| R10 | Large lots, outer neighborhoods. Fourplexes allowed under RIP2. Land division potential. | 30 ft | Controlled by FAR and setbacks |
| RM1 | Low-rise apartments, 1:1 FAR, 35 ft. Transition zone between single-family and corridors. | 35 ft | 50% of site area |
| RM2 | Medium-scale apartments, 1.5:1 FAR, 45 ft. The workhorse multifamily zone on transit corridors. | 45 ft | 60% of site area |
| RM3 | Mid-rise apartments, 2:1 FAR, 55 ft. Five stories. Near town centers and high-capacity transit. | 55 ft | 70% of site area |
| RM4 | High-rise residential, 4:1 FAR, 75 ft. Portland's densest residential zone outside Central City. | 75 ft | 85% of site area |
| RX | High-density residential near downtown. 4:1 FAR, 100 ft. Tower-scale apartments and condos. | 100 ft | 85% of site area |
| CM1 | Small-scale mixed-use, 3 stories, 1.5:1 FAR. Neighborhood nodes within residential areas. | 35 ft | 65% of site area |
| CM2 | Medium-scale mixed-use, 4 stories, 2.5:1 FAR. The workhorse zone on frequent-transit corridors. | 45 ft (base) / 55 ft (bonus) | 80% of site area |
| CM3 | Large-scale mixed-use, 6 stories, 4:1 FAR. Town centers and high-capacity transit stations. | 75 ft (base) / 85 ft (bonus) | 85% of site area |
| CE | Auto-accommodating commercial, 45 ft, 2.5:1 FAR. Allows drive-throughs and large-format retail. | 45 ft | 85% of site area |
| CX | Downtown-intensity mixed-use, 75+ ft, 4:1 FAR. Highest-density commercial zone in Portland. | 75 ft (base) / varies by plan district (often unlimited) | 100% of site area |
| EX | Mixed-use industrial/commercial/residential, 65 ft, 3:1 FAR. Creative office, maker space, live/work. | 65 ft | 85% of site area |
| EG1 | Small-lot industrial/commercial flex, 45 ft. No residential. Grid-block industrial areas. | 45 ft | 85% of site area |
| IG1 | General industrial on grid-block lots. No height limit. No residential. Protected for industrial use. | No limit | 85% of site area |
| IH | Heavy manufacturing, no restrictions on use intensity. No height or FAR limits. Most permissive industrial zone. | No limit | 85% of site area |
Single-Dwelling Residential
4 districts in Portland
R5
Residential 5,000Portland's most common residential zone. 5,000 SF minimum lots. Since RIP, duplexes through fourplexes are permitted on every R5 lot by right — no rezoning, no conditional use. Six units possible with an affordability covenant.
What you can build
- ✓Single-family home + ADU
- ✓Duplex, triplex, fourplex (by right)
- ✓Up to 6 units with affordability covenant
- ✓Cottage clusters
- ✗5+ market-rate units without affordability covenant
- ✗Commercial or retail
- ✗Apartments (need multi-dwelling zone)
Key numbers
- Height
- 30 ft
- Lot min
- 3,000 SF (infill) / 5,000 SF (standard)
- Width
- 36 ft (infill) / 50 ft (standard)
- Coverage
- Controlled by FAR and setbacks
- Front
- 10 ft
- Side
- 5 ft
- Rear
- 5 ft
What this means in practice
The FAR bump is the play. On a 5,000 SF lot: a single home gets 2,500 SF, but a fourplex gets 4,000 SF (0.8 FAR). Add an affordability covenant and you get 0.9 FAR — 4,500 SF total for 6 units. That's 750 SF per unit, tight but pencils for workforce housing. Most R5 infill deals are fourplexes because the FAR bonus more than offsets the per-unit construction cost.
R7
Residential 7,000Larger single-dwelling lots with the same RIP middle housing entitlements as R5. Fourplexes by right, but 0.4 base FAR means less buildable area per lot. Found in inner-ring neighborhoods like Woodstock, Foster-Powell, and Sellwood.
What you can build
- ✓Single-family home + ADU
- ✓Duplex, triplex, fourplex (by right)
- ✓Up to 6 units with affordability covenant
- ✓Cottage clusters
- ✗5+ market-rate units
- ✗Commercial or retail
Key numbers
- Height
- 30 ft
- Lot min
- 4,200 SF (infill) / 7,000 SF (standard)
- Width
- 50 ft
- Coverage
- Controlled by FAR and setbacks
- Front
- 15 ft
- Side
- 5 ft
- Rear
- 5 ft
What this means in practice
On a 7,000 SF R7 lot, a fourplex at 0.7 FAR gets 4,900 SF — bigger units than R5 fourplexes. But the 15-ft front setback eats more of the lot. The math often favors buying two adjacent R7 lots and land-dividing into R5-sized parcels if the geometry works. Check the lot depth — R7 lots on shallow blocks may not support rear parking.
R2.5
Residential 2,500Portland's densest single-dwelling zone. 25-ft wide lots, zero-lot-line possible. Fourplexes by right. Found along inner eastside corridors and historically platted narrow-lot neighborhoods like Ladd's Addition.
What you can build
- ✓Single-family home + ADU
- ✓Duplex, triplex, fourplex (by right)
- ✓Up to 6 units with affordability covenant
- ✓Cottage clusters
- ✓Attached houses (rowhouses)
- ✗5+ market-rate units
- ✗Commercial or retail
Key numbers
- Height
- 35 ft
- Lot min
- 1,500 SF (infill) / 2,500 SF (standard)
- Width
- 25 ft (infill) / 36 ft (standard)
- Coverage
- Controlled by FAR and setbacks
- Front
- 10 ft
- Side
- 5 ft
- Rear
- 5 ft
What this means in practice
R2.5 is the sweet spot for small-scale infill. On a standard 2,500 SF lot at 0.9 FAR (triplex+), you get 2,250 SF — three 750-SF units. On a 5,000 SF double lot, a fourplex gets 4,500 SF. The 35-ft height (vs 30 ft in R5/R7) gives you a third story. Narrow-lot rowhouse projects with two or three attached units are the most common R2.5 product.
R10
Residential 10,000Large-lot residential in outer east Portland and the West Hills. RIP2 (2022) extended middle housing to R10 zones. Fourplexes allowed by right. Many R10 lots are large enough to subdivide into two or more R5-sized parcels.
What you can build
- ✓Single-family home + ADU
- ✓Duplex, triplex, fourplex (by right)
- ✓Land division into smaller lots
- ✓Cottage clusters
- ✗5+ market-rate units (without subdivision)
- ✗Commercial or retail
Key numbers
- Height
- 30 ft
- Lot min
- 6,000 SF (infill) / 10,000 SF (standard)
- Width
- 50 ft
- Coverage
- Controlled by FAR and setbacks
- Front
- 20 ft
- Side
- 10 ft
- Rear
- 10 ft
What this means in practice
The real play on R10 lots is land division, not building one fourplex. A 10,000 SF lot can split into two 5,000 SF lots, each supporting a fourplex — 8 units total instead of 4. FAR doesn't apply to lots over 10,000 SF, so on the pre-split lot you're limited only by height and coverage. Run the numbers both ways: fourplex on the full lot vs. subdivide and build two duplexes.
Multi-Dwelling Residential
5 districts in Portland
RM1
Multi-Dwelling 1Portland's entry-level multi-dwelling zone. 1-3 story buildings at the edges of mixed-use centers and along neighborhood corridors. One unit per 2,500 SF of lot area. No unit count cap — density controlled by FAR.
What you can build
- ✓Apartments (low-rise)
- ✓Townhouses and rowhouses
- ✓Duplexes through fourplexes
- ✓ADUs
- ✓Group living
- ✗Commercial or retail (need CM zone)
- ✗Industrial
Key numbers
- Height
- 35 ft
- Lot min
- 4,000 SF (houses/duplex/triplex/fourplex)
- Width
- None specified
- Coverage
- 50% of site area
- Front
- 10 ft
- Side
- 5 ft (buildings up to 35 ft)
- Rear
- Eastern Pattern Area: 25% of lot depth / elsewhere: 5 ft
What this means in practice
At 1:1 FAR and 50% coverage, a 10,000 SF RM1 lot yields 10,000 SF of gross floor area — roughly 10-12 apartments at ~850 SF each. Three stories at 50% coverage = 15,000 SF gross, but FAR caps you at 10,000 SF, so you're building less than full coverage on upper floors. This zone pencils for walk-up apartments without structured parking.
RM2
Multi-Dwelling 2Portland's most common apartment zone, mapped around centers and corridors with frequent transit. 3-4 story buildings. 1.5 FAR with bonus potential. One unit per 1,450 SF minimum density.
What you can build
- ✓Apartment buildings (3-4 stories)
- ✓Townhouses and rowhouses
- ✓Group living
- ✓ADUs
- ✗Standalone commercial
- ✗Industrial
Key numbers
- Height
- 45 ft
- Lot min
- 10,000 SF (houses/duplex/triplex/fourplex)
- Width
- None specified
- Coverage
- 60% of site area
- Front
- 10 ft
- Side
- 5 ft (buildings up to 55 ft)
- Rear
- Eastern Pattern Area: 25% of lot depth / elsewhere: 5 ft
What this means in practice
RM2 is where Portland's apartment math starts to pencil at scale. On a half-acre (21,780 SF) lot: 1.5 FAR = 32,670 SF gross. At 60% coverage and 4 stories, you get ~52,000 SF of buildable volume but FAR caps you at ~33,000 SF — roughly 35-40 apartments. Surface parking or tuck-under usually works at this density, avoiding the cost of structured parking.
RM3
Multi-Dwelling 3Mid-rise apartment zone near town centers and along high-capacity transit lines. 2:1 FAR allows significantly more density than RM2. Minimum density of 1 unit per 1,000 SF of lot area.
What you can build
- ✓Mid-rise apartment buildings (5 stories)
- ✓Townhouses
- ✓Group living
- ✗Standalone commercial
- ✗Industrial
Key numbers
- Height
- 55 ft
- Lot min
- 10,000 SF
- Width
- None specified
- Coverage
- 70% of site area
- Front
- 5 ft
- Side
- 5 ft (up to 55 ft) / 10 ft (over 55 ft)
- Rear
- 5 ft
What this means in practice
At 2:1 FAR and 5 stories, a half-acre RM3 site yields ~43,500 SF — roughly 50-55 apartments. The 70% coverage is generous enough that you can often fit surface parking behind the building at this scale. But at 50+ units, the project triggers Inclusionary Housing (20+ units), so bake in 20% at 80% AMI or 10% at 60% AMI. The deeper affordability option often pencils better because fewer units are restricted.
RM4
Multi-Dwelling 4Portland's highest-density residential zone outside the Central City. 4:1 FAR with 75-ft height. Found near the Lloyd District, along MLK/Grand, and close to MAX stations. Minimum density of 1 unit per 1,000 SF.
What you can build
- ✓High-rise apartment buildings
- ✓Townhouses
- ✓Group living
- ✗Standalone commercial
- ✗Industrial
Key numbers
- Height
- 75 ft
- Lot min
- 10,000 SF
- Width
- None specified
- Coverage
- 85% of site area
- Front
- 3 ft
- Side
- 5 ft (up to 55 ft) / 10 ft (over 55 ft)
- Rear
- 5 ft
What this means in practice
At 4:1 FAR on a half-acre: 87,000 SF of building — 100+ apartments. Structured parking is mandatory at this density. The 85% coverage and 3-ft front setback means you're building nearly lot-line to lot-line. These are the sites where Portland's largest apartment projects happen outside downtown. Compare land cost per entitled SF against CM3 or CX sites, which may offer commercial income to offset higher land prices.
RX
Central ResidentialThe most intense residential zone in Portland. Mapped in and around the Central City — the Pearl District, South Waterfront, and NW 23rd corridors. 100-ft height allows 8-10 story buildings. Minimum density of 1 unit per 500 SF.
What you can build
- ✓High-rise apartments and condos
- ✓Group living
- ✓Limited retail in ground floor
- ✗Large-scale commercial (need CX)
- ✗Industrial
Key numbers
- Height
- 100 ft
- Lot min
- None
- Width
- None
- Coverage
- 85% of site area
- Front
- 0 ft
- Side
- 0 ft
- Rear
- 0 ft
What this means in practice
Zero setbacks on all sides. At 4:1 FAR on a 20,000 SF RX site: 80,000 SF building — 100-120 units at ~700 SF average. The minimum density (1 unit per 500 SF of lot) means you must build at least 40 units on that site. Below-grade parking is standard. RX sites trade at a premium because the entitlement is high-rise residential without commercial zoning constraints.
Commercial / Mixed Use
5 districts in Portland
CM1
Commercial Mixed Use 1Small-scale neighborhood mixed-use. Intended for dispersed commercial nodes within lower-density residential areas — think a corner store or coffee shop with apartments above. Buildings generally 3 stories.
What you can build
- ✓Retail, restaurant, office (ground floor)
- ✓Apartments above commercial
- ✓Standalone residential
- ✓Live/work
- ✗Drive-throughs
- ✗Auto-oriented commercial
- ✗Industrial
Key numbers
- Height
- 35 ft
- Lot min
- None
- Width
- None
- Coverage
- 65% of site area
- Front
- 0 ft
- Side
- 0 ft (5 ft abutting residential)
- Rear
- 0 ft (5 ft abutting residential)
What this means in practice
CM1 is the neighborhood-scale play. On a typical 5,000 SF corner lot at 1.5 FAR: 7,500 SF of building — a 1,500 SF retail space with 6-8 apartments above. The inclusionary housing bonus pushes FAR to 2.5:1 (12,500 SF on that same lot), but you trigger the 20-unit IH mandate at that scale. Best for small mixed-use projects under 20 units that avoid IH entirely.
CM2
Commercial Mixed Use 2Portland's most common commercial zone. Mapped along corridors with frequent bus service — Division, Hawthorne, Belmont, Sandy, 82nd. Buildings generally 4 stories. Wide range of commercial and residential uses.
What you can build
- ✓Mixed-use (residential + commercial)
- ✓Standalone residential or commercial
- ✓Office buildings
- ✓Hotels and motels
- ✓Restaurants and retail
- ✗Drive-throughs (conditional use in some locations)
- ✗Heavy industrial
- ✗Outdoor storage
Key numbers
- Height
- 45 ft (base) / 55 ft (bonus)
- Lot min
- None
- Width
- None
- Coverage
- 80% of site area
- Front
- 0 ft
- Side
- 0 ft (5 ft abutting residential)
- Rear
- 0 ft (5 ft abutting residential)
What this means in practice
CM2 is where most of Portland's corridor development happens. On a quarter-acre (10,890 SF) lot at 2.5 FAR: 27,225 SF of building — roughly 25-30 apartments over 3,000 SF of retail. At bonus FAR (3.5:1): 38,115 SF, or 35-40 apartments. The 45-ft base height fits 4 wood-frame stories over ground-floor retail. Bonus height (55 ft) allows a fifth story. Projects over 20 units trigger IH, so most CM2 projects include affordable units to unlock the bonus.
CM3
Commercial Mixed Use 3Portland's largest-scale commercial zone outside the Central City. Mapped at town centers (Hollywood, Lents, St. Johns) and near MAX stations. 6-story base height with bonus potential. Wide range of uses including entertainment and large retail.
What you can build
- ✓Large mixed-use buildings
- ✓Apartment buildings (6+ stories)
- ✓Office and medical office
- ✓Hotels
- ✓Entertainment venues
- ✓Large-format retail
- ✗Heavy industrial
- ✗Outdoor storage
Key numbers
- Height
- 75 ft (base) / 85 ft (bonus)
- Lot min
- None
- Width
- None
- Coverage
- 85% of site area
- Front
- 0 ft
- Side
- 0 ft (5 ft abutting residential)
- Rear
- 0 ft (5 ft abutting residential)
What this means in practice
CM3 is Portland's mid-rise commercial zone. On a half-acre at 4:1 FAR: ~87,000 SF — enough for 80-100 apartments over 10,000 SF of retail. Bonus FAR (5:1) pushes that to ~109,000 SF. Structured parking is required at this density. These sites command premium prices near MAX stations. Compare with RM4 if you don't need commercial entitlement — same FAR, potentially lower land cost.
CE
Commercial EmploymentThe zone for auto-oriented commercial uses that don't fit walkable mixed-use corridors — car dealerships, drive-throughs, big-box retail, large-format stores. Also allows housing. Found along arterials like 82nd Ave and outer Sandy Blvd.
What you can build
- ✓Large-format retail
- ✓Drive-throughs
- ✓Auto dealerships and service
- ✓Office and medical
- ✓Apartments (allowed but uncommon)
- ✓Hotels
- ✗Heavy industrial
- ✗Outdoor storage over 10,000 SF
Key numbers
- Height
- 45 ft
- Lot min
- None
- Width
- None
- Coverage
- 85% of site area
- Front
- 5 ft (or 0 ft on transit streets)
- Side
- 0 ft (5 ft abutting residential)
- Rear
- 0 ft (5 ft abutting residential)
What this means in practice
CE is where drive-throughs and auto-oriented uses are entitled — everything prohibited in CM zones. If you're buying a CE site on a growing corridor, the long play may be rezoning to CM2 or CM3 as transit service improves. Near-term, CE sites work for large-format retail pad deals. The residential entitlement is real but rarely used because the auto-oriented surroundings suppress apartment rents.
CX
Central CommercialPortland's most intense commercial zone. Mapped in and around the Central City — downtown, Pearl District, Lloyd District. No practical height cap in many plan districts. Highest FAR. Full range of urban uses.
What you can build
- ✓High-rise mixed-use towers
- ✓Office towers
- ✓Hotels
- ✓Large-format retail
- ✓Entertainment and cultural venues
- ✓High-density residential
- ✗Heavy industrial
- ✗Bulk storage
Key numbers
- Height
- 75 ft (base) / varies by plan district (often unlimited)
- Lot min
- None
- Width
- None
- Coverage
- 100% of site area
- Front
- 0 ft
- Side
- 0 ft
- Rear
- 0 ft
What this means in practice
CX in the Central City plan district often has no effective height limit — just FAR and design review. The real constraint is FAR transfer and bonus acquisition. On a 20,000 SF downtown lot at 4:1 base: 80,000 SF. With bonus and FAR transfer, projects routinely reach 6-8:1 effective FAR — 120,000-160,000 SF. Below-grade parking is standard. These are Portland's trophy development sites. Design review adds 3-6 months.
Employment & Industrial
4 districts in Portland
EX
Central EmploymentPortland's most flexible employment zone. Allows industrial, commercial, and residential uses in the same building. Mapped in the Central Eastside Industrial District, parts of inner NW, and near downtown. The go-to zone for creative office, maker space, and live/work.
What you can build
- ✓Office and creative office
- ✓Light manufacturing and maker space
- ✓Retail and restaurants
- ✓Apartments and live/work
- ✓Warehousing (existing)
- ✗Heavy industrial
- ✗Large-scale warehousing (new)
Key numbers
- Height
- 65 ft
- Lot min
- None
- Width
- None
- Coverage
- 85% of site area
- Front
- 0 ft
- Side
- 0 ft
- Rear
- 0 ft
What this means in practice
EX is the Central Eastside play. A 10,000 SF EX lot at 3:1 FAR = 30,000 SF — enough for a 5-story creative office or mixed-use building. The inclusionary housing bonus pushes FAR to 5:1 (50,000 SF), which is significant. Many developers are converting old warehouses and building new mixed-use on EX lots along MLK, Grand, and Water Ave. The residential entitlement is what makes EX more valuable than EG or IG.
EG1
General Employment 1Light industrial and employment zone on smaller lots with a grid street pattern. Manufacturing, warehousing, office, and some retail. No residential allowed. Often found as a buffer between industrial and commercial zones.
What you can build
- ✓Light manufacturing
- ✓Warehousing and distribution
- ✓Office and tech
- ✓Retail (limited)
- ✗Residential (any type)
- ✗Heavy industrial
Key numbers
- Height
- 45 ft
- Lot min
- None
- Width
- None
- Coverage
- 85% of site area
- Front
- 5 ft
- Side
- 0 ft
- Rear
- 0 ft
What this means in practice
EG1 sites near the Central Eastside or inner NW may be rezoning candidates to EX, which adds residential entitlement and significantly increases land value. Check the Comprehensive Plan designation — if it says Mixed Use Employment, the path to EX is clearer. Near-term, EG1 pencils for flex office/warehouse.
IG1
General Industrial 1Portland's protected industrial land. No height limit, no FAR cap. Mapped in the Columbia Corridor, Swan Island, and Brooklyn Yard. Prime Industrial overlay (k) on many IG1 sites prevents rezoning.
What you can build
- ✓Manufacturing and processing
- ✓Warehousing and distribution
- ✓Freight and logistics
- ✓Contractor yards
- ✗Residential
- ✗Retail (except accessory)
- ✗Office (except accessory)
Key numbers
- Height
- No limit
- Lot min
- None
- Width
- None
- Coverage
- 85% of site area
- Front
- 5 ft (25 ft abutting residential)
- Side
- 0 ft (10 ft abutting residential)
- Rear
- 0 ft (10 ft abutting residential)
What this means in practice
If a site has the Prime Industrial (k) overlay, don't plan on rezoning — the city will fight it. These sites are valued for industrial use only. Check for environmental overlays (c or p zones) along waterways, which can eliminate large portions of buildable area. Columbia Corridor IG1 sites near the airport are the strongest industrial market in the metro.
IH
Heavy IndustrialPortland's heaviest zoning. All industrial uses including those with major off-site impacts. No height or FAR limits. Mapped in the Rivergate area, NW industrial district, and parts of the Columbia Corridor.
What you can build
- ✓Heavy manufacturing
- ✓Chemical processing
- ✓Large-scale warehousing
- ✓Marine terminals
- ✓Utility installations
- ✗Residential
- ✗Retail
- ✗Office (except accessory)
Key numbers
- Height
- No limit
- Lot min
- None
- Width
- None
- Coverage
- 85% of site area
- Front
- 5 ft (25 ft abutting residential)
- Side
- 0 ft (10 ft abutting residential)
- Rear
- 0 ft (10 ft abutting residential)
What this means in practice
IH sites are the rarest and most difficult to rezone in Portland. If you're evaluating an IH site for non-industrial use, stop — the city's Industrial Land Supply analysis treats these as permanent industrial. The value is in the use: heavy manufacturing, marine cargo, bulk materials. Environmental overlay zones along the Willamette are common and significantly constrain development near the water.
Development Bonus Program
Portland offers FAR and height bonuses across multi-dwelling (RM1-RM4, RX) and commercial/mixed-use (CM1-CM3, CE, CX, EX) zones for projects that include affordable housing. The Inclusionary Housing mandate requires projects of 20+ units to provide either 20% of units at 80% AMI or 10% at 60% AMI. In exchange, projects receive bonus FAR (typically 1.0 additional) and bonus height (typically 10 ft). In single-dwelling zones, the Residential Infill Project grants additional FAR (up to 0.9:1) for projects with 3+ units and deeper affordability covenants allowing up to 6 units on a single lot. Compliance options include building affordable units on-site, off-site, or paying a fee-in-lieu. The deeper affordability option (10% at 60% AMI) often pencils better than the 80% AMI path because fewer total units are restricted.
Overlay Districts
Design Overlay (d)
Applied to areas where neighborhood design character is a priority. Triggers design review for most new construction and major alterations. Found along many commercial corridors and in plan districts. Type III review for large projects, Type II for medium. Community Design Standards provide an alternative path for smaller projects that meet prescriptive criteria. Budget 2-4 months for design review.
Historic Resource Protection Overlay
Protects designated historic landmarks, conservation landmarks, and contributing resources in historic and conservation districts. Exterior modifications visible from the street require historic resource review. Demolition of contributing resources requires demolition review with a 120-day delay. Portland has 20+ historic districts including Irvington, Ladd's Addition, King's Hill, Alphabet District, and Lair Hill. Factor in 1-3 months for review.
Environmental Conservation (c) and Protection (p) Zones
Mapped along streams, wetlands, and steep slopes. The c-zone allows some development with mitigation; the p-zone is essentially a no-build zone. Common along Johnson Creek, Fanno Creek, and Willamette River tributaries. These overlays can eliminate 20-50% of a site's buildable area. Always check before making an offer — environmental review adds significant time and cost.
Greenway Overlay (g, i, n, q, r)
Affects property along the Willamette River. Multiple sub-zones control development intensity, setbacks from the river, and public access requirements. Greenway review required for most development. The river setback (typically 25 ft or more) reduces buildable area. South Waterfront and other riverfront projects must navigate both greenway and environmental review.
Aircraft Landing (h) and Noise Impact (x) Zones
Near Portland International Airport. The h-zone limits structure height to protect flight paths. The x-zone requires sound insulation for new residential construction. Both affect development feasibility and cost — noise insulation adds $3-5/SF to residential construction. Check FAA Part 77 surfaces before designing anything tall near PDX.
Scenic Resource (s) Zone
Limits building height and requires landscaping to protect scenic views. Mapped along scenic corridors and viewpoints including the West Hills, Rocky Butte, and Mt. Tabor. Can reduce allowable height below the base zone maximum. Check the specific scenic corridor standards before assuming base zone height applies.
Prime Industrial (k) Zone
Protects industrial land from conversion to non-industrial uses. Prohibits rezoning to residential or commercial. Mapped over many IG1, IG2, and IH sites in the Columbia Corridor and harbor areas. If a site has the k-overlay, plan for industrial use only — the city will not support a comp plan amendment.
Centers Main Street (m) Overlay
Encourages a pedestrian-oriented mix of commercial, residential, and employment uses along designated main streets within centers. May modify base zone standards to promote ground-floor active uses and limit auto-oriented development. Check for additional ground-floor use requirements.
Frequently Asked Questions
How do I check zoning for a specific property in Portland?
Use PortlandMaps.com — enter any address to see the base zone, overlay zones, plan districts, and comprehensive plan designation. The zoning map shows the zone code (e.g., R5, CM2) and any overlay letters (d, h, c). For what the zoning actually means for development potential, you need to cross-reference with Title 33.
Can I build a fourplex on my single-family lot?
Yes. Since the Residential Infill Project (2020) and RIP2 (2022), duplexes, triplexes, and fourplexes are allowed by right on virtually every residential lot in Portland — R20, R10, R7, R5, and R2.5 zones. No conditional use permit, no rezoning. You get a FAR bonus for more units: a fourplex on an R5 lot gets 0.8:1 FAR vs 0.5:1 for a single home. With an affordability covenant, you can build up to 6 units.
What is the Residential Infill Project (RIP)?
RIP is Portland's implementation of Oregon's HB 2001 middle housing law. Part 1 (2020) legalized duplexes through fourplexes on all R5 and R2.5 lots, gave FAR bonuses for more units, and allowed up to 6 units with an affordability covenant. Part 2 (2022) extended middle housing to the larger-lot R10 and R20 zones. Since 2020, Portland has permitted over 1,400 middle housing units under RIP — it's producing real housing at scale.
What triggers Portland's Inclusionary Housing requirement?
Any residential project proposing 20 or more new units must comply. You choose one path: 20% of units at 80% AMI, or 10% of units at 60% AMI, or build equivalent units off-site, or pay a fee-in-lieu. The fee-in-lieu amount is set by formula and varies by location. Projects that include affordable units on-site receive FAR and height bonuses that partially offset the cost. Most developers building 20+ units go with the 10% at 60% AMI option because fewer units are restricted.
What's the difference between CM1, CM2, and CM3?
Scale and intensity. CM1 is neighborhood-scale (3 stories, 1.5 FAR) for corner stores and small mixed-use. CM2 is corridor-scale (4 stories, 2.5 FAR) for Portland's main commercial streets with frequent transit. CM3 is town-center-scale (6 stories, 4 FAR) near MAX stations and in designated centers like Hollywood or Lents. All allow mixed-use with residential. The higher the number, the more you can build.
How does Oregon's HB 2001 affect Portland zoning?
HB 2001 (2019) required all Oregon cities over 25,000 population to allow middle housing — duplexes, triplexes, fourplexes, townhouses, and cottage clusters — in residential zones. Portland went further with its Residential Infill Project, adding FAR bonuses for density and allowing up to 6 units with affordability covenants. The practical effect: single-family-only zoning no longer exists in Portland. Every residential lot can support at least a duplex by right.
When do I need design review?
Design review is triggered by the Design Overlay (d) zone, which is mapped along many commercial corridors and in plan districts like the Central City. Most new construction and major alterations in d-zones require review. Smaller projects can often use Community Design Standards (prescriptive criteria) instead of discretionary design review. Outside d-zones, there's generally no design review for projects that meet base zone standards. Budget 2-4 months for Type II or III design review.
What are environmental overlay zones and how do they affect development?
Environmental Conservation (c) and Protection (p) zones are mapped along streams, wetlands, steep slopes, and natural areas. The p-zone is essentially a no-build zone. The c-zone allows limited development with environmental review and mitigation. These overlays can eliminate 20-50% of a site's buildable area. Check PortlandMaps before buying — sites along Johnson Creek, Fanno Creek, and the West Hills commonly have environmental overlays that dramatically reduce development potential.
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