Fitzsimmons 1 Memo To: Dr. Charles Warnken Cc: From: Emily Fitzsimmons Date: February 25, 2021 Subject: Overview of Municipal Zoning in Portland, OR This memo summarizes information from the current zoning code of Portland, OR. Specifically, it provides an overview of the residential and commercial zoning as well as the Planned Unit Development (PUD) ordinance. Within the residential and commercial sections, minimum lot size, lot density, and maximum building coverage are detailed; the PUD section entails the intent, requirements, and benefits of PUD zoning as well as its relation to other zoning ordinances. Context and Research This memo outlines information about the residential, commercial, and PUD zoning ordinances strictly from the city of Portland’s government website, which provides digital versions of the city’s zoning documents. That data is organized into Tables 1-4 at the end of this document. Portland’s current zoning map is shown below in Figure 1 for reference. Figure 1. Zoning Map of Portland, OR
(“Citywide”)
Fitzsimmons 2 Residential Zoning in Portland, OR Single-Dwelling Residential Zoning As illustrated in Table 1 at the end of this document, Portland has an extensive residential zoning section with six unique zones dedicated to single-family housing alone (“33.110” 2). Though they all share many of the same allowed, limited, and conditional uses, these six zones differ from each other in minimum lot size, density, and lot coverage. In particular, the minimum lot sizes range widely from 52,000 sq. ft. in Single-Dwelling Residential Farm/Forest (RF) to 1,600 sq. ft. in Single-Dwelling Residential 2,500 (R2.5) (“33.610” 3). Along with the massive minimum lot size, RF has very low density and maximum building coverage, which is calculated as 4,500 sq. ft. added to 7.5% of the lot area (“33.110” 20). As an example, in an RF lot that is the minimum 52,000 sq. ft., the maximum amount that could be covered by the structure would be 16%. These requirements are logical for this zone because RF abuts Portland’s largest open spaces, which would be environmentally sensitive (“Citywide”). Likewise, zones Single-Dwelling Residential 20,000 (R20), Single-Dwelling Residential 10,000 (R10), and Single-Dwelling Residential 7,000 (R7) dominate the land along Open Space (OS) and RF (“Citywide”). Because these zones are meant for low- to medium-density single-family housing, they act as a transitional buffer between the low-density agricultural and wild areas and the higher density housing and commercial areas (“Citywide”; “33.110” 6-8). The R20, R10, and R7 minimum lot sizes are 12,000 sq. ft., 6,000 sq. ft., and 4,200 sq. ft., respectively; the maximum building coverage for R20 and R10 are calculated by adding 2,250 sq. ft. to 15% of lot area while R7 maximum building coverage is equal to 1,500 sq. ft. plus 37.5% of the lot area (“33.610” 3; “33.110” 20). At the minimum lot sizes, these zones’ maximum building coverage would equal 33% for R20, 52% for R10, and 73% for R7. The Single-Dwelling Residential 5,000 (R5) zone is the most common residential zone, especially in the central part of the city, with low- to medium-density single-family homes on lots of at least 3,000 sq. ft. (“Citywide”; “33.610” 3; “33.110” 6-8). R5’s maximum building coverage is calculated just like the R7 zone, so up to 87.5% of the lot could be covered by structures (“33.610” 20). Lastly, Single-Dwelling Residential 2,500 (R2.5) is the most dense single-family housing zone and acts as a buffer between R5 and the Commercial/Mixed-Use zones. R2.5’s minimum lot size is the smallest at 1,600 sq. ft. with a maximum building coverage of 50% (“33.610” 3, 6-8; “33.110” 20; “Citywide”). The lot size and density requirements for these zones were last updated March 31, 2017 while the general SingleDwelling Residential zoning ordinance was last updated September 11, 2020 (“33.110” 1; “33.610” 1). Multi-Dwelling Residential Zoning In addition to the single-dwelling zones, Portland also utilizes six multi-dwelling zoning categories based on neighborhood density (“33.120” 2). The least dense of these is the Residential Manufactured Dwelling Park (RMP) zone, which is meant for low-scale, manufactured housing (3). Since this housing type consists of small, single dwelling houses with yards, the maximum building cover is 50% of the site area (14). Residential Multi-Dwelling 1 (RM1) is also meant for small-scale housing that limited to three stories; RM1 acts as a transition between single-dwelling zones and high traffic corridors (2). The minimum lot size for RM1 varies depending on the housing type: Both detached and attached houses and duplexes must
Fitzsimmons 3 have lots of 1,600 sq. ft.; triplexes and fourplexes must have lots of 2,000 sq. ft., and other multidwelling development must have lots of 4,000 sq. ft. (“33.612” 2). All RM1 lots have a maximum building coverage of 50%, however (“33.120” 14). The Residential Multi-Dwelling 2 (RM2), Residential Multi-Dwelling 3 (RM3), and Residential Multi-Dwelling 4 (RM4) zones are all located in medium- to high-density areas close to commercial and transit services. The RM2 zone limits building height to four stories and building coverage to 60%-70% of the lot area (“33. 120” 3, 14). Buildings in RM3 are limited to six stories while RM4 and Central Residential (RX) do not have a limit on building height (3). Both RM3 and RM4 have a maximum lot coverage of 85% (14). RX zoning designation is the densest residential zoning and is meant to be located next to intense areas, like those zoned Central Commercial (3). With the exception of Residential Multi-Dwelling 1 (RM1), all the multi-dwelling zones have minimum lot sizes of 10,000 sq. ft. in order to accommodate many units (“33. 612” 2). The multi-dwelling zone ordinances were last updated in March and August of 2020 (“33.120” 1; “33.612” 1). Notably, Portland’s residential zoning is Euclidean but not cumulative because some of the residential zones have density minimums; additionally, not all low-density structures are allowed in higher density zones, namely manufactured houses (“33.120” 13; “33.610” 2). Commercial Zoning in Portland, OR Although Portland’s zoning is Euclidean, the city does emphasize mixed-use development, particularly in their commercial zoning ordinances. However, the commercial zoning is not cumulative: Like the residential zoning ordinances, some of the city’s commercial zones also have minimum density regulations so that not all lower densities are allowed in higher density areas by right. At the same time, some of the commercial zones do not have density minimums and none have minimum lot sizes, but the zoning code does require that the lot size, placement, and shape must be appropriate for the use and location. This zoning ordinance was last updated March 1, 2020 (“33.130” 1, 15; “33.613” 1). The Portland zoning code divides the commercial ordinance into six different zones for varying intensities and lot coverages. The Commercial Residential (CR) and Commercial/Mixed-Use 1 (CM1) zones allow small-scale commercial uses in single-dwelling residential and mixed-use areas, respectively (“33.130” 2-3). Additionally, they both limit building coverage at 75%-85% of the lot area, and CM1 limits building height to three stories (3, 15). Meanwhile, the Commercial Employment (CE) and Commercial/Mixed-Use 2 (CM 2) zones are meant for medium-scale commercial establishments located along major corridors; likewise, they both limit building height to four stories. The critical difference between the two zones is their relationship to the automobile: CM2 zones are meant for dense, mixed-use areas that are built for the pedestrian while CE zones are developed to accommodate personal vehicles (33.130” 3-4). This includes drive-through facilities, high traffic roads, and streets built to accommodate trucks (54). Moreover, CM2 allows more building coverage at 85%-100% of the lot while the CE maximum building coverage is 75%-85% (5).
Fitzsimmons 4 Lastly, Commercial/Mixed-Use 3 (CM3) and Central Commercial (CX) zoning allows largescale commercial development in intensely used areas. Both zones allow up to 100% of the lot to be covered by structures because of the intensity of their areas, but CM3 does limit building height to six stories (“33.130” 4, 15). Planned Development in Portland, OR Requirements and Allowances of Planned Development Zoning In order to avoid issues of inflexibility that often come with zoning, the city of Portland does have a Planned Development (PD) ordinance so that developers have the “opportunity for innovative and creative development” (“33.270” 1). In particular, the city utilizes PD to encourage pedestrian- and transit-oriented design, improvements and accessibility to public spaces, more active gathering places, new open spaces, continued access to light and air, affordable housing, and energy efficient development (1). With a PD designation, a development can include additional units, housing types, commercial uses, and building height and floor area ratio (FAR) as well as other changes to development rights and dimensions (2-3). However, the development must meet certain requirements to gain the flexibility of PD designation, including affordable housing, a plaza or park, and energy efficient buildings; additionally, the development must either meet the Community Design Standards or obtain approval from the Design Commission in a Design Review (“33.270” 4-5; “33.720” 1). Relationship to Existing Regulations As stated above, the PD zone is meant to provide flexibility to the municipal zoning code; namely, that flexibility applies to the residential and commercial/mixed-use zones in order to encourage more affordable housing and dense, pedestrian-oriented commercial areas. On that note, PDs must meet the minimum density and FAR requirements; these cannot be adjusted in a PD. Additionally, a PD does not necessarily have to be but may be part of a Land Division proposal, particularly if there are site conditions that require subdivision or if rights-of-way are necessary (“33.270” 1-2). Conclusion The city of Portland follows Euclidean zoning in their residential and commercial/mixed-use zones but not cumulative zoning as the city is trying to increase density over time. In that vein, Portland has also incorporated PDs into the zoning code to add flexibility to its residential and commercial/mixed-use zoning regulations, but the PD ordinance does require that the development contribute to the public good through affordable housing, energy-efficient buildings, public spaces, and dense, human-scale design. With the heavy preference for singledwelling residential areas in the existing code, the shift to more affordable and denser housing will be difficult; however, the commercial/mixed-use zoning ordinances already places a much greater emphasis on higher intensities and transit-oriented design, which indicates greater progress toward intense commercial and mixed-use development.
Fitzsimmons 5 Table 1. Residential and Commercial Zoning in Portland, OR Zoning Category Minimum Density Summary Notes Lot Size (lots:1acre) (Sq. Ft.) RF (Single-Dwelling 52,000 0.83:1a Very low-density residential; zoned for single Residential sq. ft. family homes; group living, commercial, Farm/Forest) industrial, institutional, aviation, mining, agricultural, and railroad uses only allowed under conditional or limited uses R20 (Single12,000 3.63:1a Low-density residential; zoned for single Dwelling Residential sq. ft. family homes; group living, commercial, 20,000) institutional, agricultural, and railroad use only allowed under conditional uses R10 (Single6,000 7.26:1a Low- to medium-density residential; zoned for Dwelling Residential sq. ft. single family homes; group living, commercial, 10,000) institutional, agricultural, and railroad use only allowed under conditional uses R7 (Single-Dwelling 4,200 10.37:1a Low- to medium-density residential; zoned for Residential 7,000) sq. ft. single family homes; group living, commercial, institutional, agricultural, and railroad use only allowed under conditional uses R5 (Single-Dwelling 3,000 14.52:1a Low- to medium-density residential; zoned for Residential 5,000) sq. ft. single family homes; group living, commercial, institutional, agricultural, and railroad use only allowed under conditional uses R2.5 (Single1,600 27.22:1a Low- to medium-density residential; zoned for Dwelling Residential sq. ft. single family homes; group living, commercial, 2,500) institutional, agricultural, and railroad use only allowed under conditional uses RM1 (Residential Variable Small-scale multi-dwelling zoning; meant as Multi-Dwelling 1) transition between single-dwelling and higher traffic corridors; 1-3 stories Multi-Dwelling 4,000 10.89:1a Structures or sq. ft. Development Attached Houses and Attached Duplexes
Detached Houses and Duplexes Triplexes and Fourplexes
RM2 (Residential Multi-Dwelling 2) Multi-Dwelling Structures or Development
1,600 sq. ft. 1,600 sq. ft. 2,000 sq. ft. Variable
27.23:1a
10,000 sq. ft.
4.36:1a
27.23:1a 21.78:1a Medium-scale multi-dwelling zoning; meant for denser areas served by transit; 1-4 stories
Fitzsimmons 6 Attached Houses and Attached Duplexes Detached Houses and Duplexes Triplexes and Fourplexes
none
n/a
none
n/a
none Variable
n/a
Multi-Dwelling Structures or Development Attached Houses and Attached Duplexes
10,000 sq. ft.
4.36:1a
none
n/a
Detached Houses and Duplexes Triplexes and Fourplexes
none
n/a
none Variable
n/a
10,000 sq. ft.
4.36:1a
none
n/a
none
n/a
none None none
n/a n/a Highest intensity of multi-dwelling zoning; includes additional design overlay zoning n/a
none
n/a
none
n/a
none Variable
n/a
10,000 sq. ft.
4.36:1a
none
n/a
none
n/a
none
n/a
RM3 (Residential Multi-Dwelling 3)
RM4 (Residential Multi-Dwelling 4)
Multi-Dwelling Structures or Development Attached Houses and Attached Duplexes Detached Houses and Duplexes Triplexes and Fourplexes
RX (Central Residential) Multi-Dwelling Structures or Development Attached Houses and Attached Duplexes Detached Houses and Duplexes Triplexes and Fourplexes
RMP (Residential Manufactured Dwelling Park) Multi-Dwelling Structures or Development Attached Houses and Attached Duplexes Detached Houses and Duplexes Triplexes and Fourplexes
Multi-dwelling zoning for medium to highdensity areas close to commercial and transit services; includes additional design overlay zoning; 1-6 stories
Multi-dwelling zoning for high-density areas close to commercial and transit services; includes additional design overlay zoning; 17+ stories
Low-scale multi-dwelling zoning meant for manufactured housing
Fitzsimmons 7 CR (Commercial Residential)
none
CM1 (Commercial/Mixed Use 1) CM2 (Commercial/Mixed Use 2) CM3 (Commercial/Mixed Use 3) CE (Commercial Employment)
none
n/a Low intensity zoning for small-scale commercial located in single-dwelling residential areas n/a Zoning for small-scale commercial located in mixed-use areas; 1-3 stories
none
n/a Zoning for medium-scale commercial located in commercial corridors and mixed-use areas; 1-4 stories none n/a Zoning for large-scale commercial in intensely used areas; 1-6 stories; includes additional design overlay zoning none n/a Zoning for medium-scale commercial along major roads; accommodates personal vehicles; 1-4 stories CX (Central none n/a Zoning for commercial in most intense areas; Commercial) includes additional design overlay zoning (“33.110” 2, 6-9; “33.120” 2; “33.130” 2; “33.610” 3; “33.613” 1) Table 2. Maximum Lot Coverage for RF-R2.5 Zones in Portland, OR Lot size Max building coverage Less than 3,000 sq. ft. 3,000 sq. ft.-4,999 sq. ft. 5,000 sq. ft.-19,999 sq. ft. 20,000 sq. ft. and above (“33.110” 20)
50% of lot area 1,500 sq. ft. + 37.5% of lot 2,250 sq. ft. + 15% of lot 4,500 sq. ft. + 7.5% of lot
Table 3. Maximum Lot Coverage for RM1-RMP Zones in Portland, OR Zone Max Building Coverage RM1 50% of site area RM2 60%-70% of site area RM3 85% of site area RM4 85% of site area RX 100% of site area RMP 50% of site area (“33.120” 13) Table 4. Maximum Lot Coverage for CR-CX Zones in Portland, OR Zone Max Building Coverage CR 75%-85% CM1 75%-85% CM2 CM3
85%-100% 85%-100%
Fitzsimmons 8 CE CX (“33.130” 15)
75%-85% 100%
Fitzsimmons 9 References “Citywide Zoning Map.” Planning Maps, Bureau of Planning and Sustainability, City of Portland, 1 March 2021, https://www.portland.gov/bps/planning-maps#toc-citywidezoning-map. Accessed 26 Feb. 2021. “33.110 Single-Dwelling Zones.” Title 33 Planning and Zoning, City of Portland, 11 Sept. 2020, https://www.portland.gov/code/33/100s/110. Accessed 13 Feb. 2021. “33.120 Multi-Dwelling Zones.” Title 33 Planning and Zoning, City of Portland, 10 Aug. 2020, https://www.portland.gov/code/33/100s/120. Accessed 13 Feb. 2021. “33.130 Commercial/Mixed Use Zones.” Title 33 Planning and Zoning, City of Portland, 1 March, 2020, https://www.portland.gov/code/33/100s/130. Accessed 13 Feb. 2021. “33.270 Planned Development.” Title 33 Planning and Zoning, City of Portland, 1 March 2020, https://www.portland.gov/code/33/200s/270. Accessed 13 Feb. 2021. “33.610 Lots in RF Through R5 Zones.” Title 33 Planning and Zoning, City of Portland, 31 March 2017, https://www.portland.gov/code/33/600s/610. Accessed 14 Feb. 2021. “33.612 Lots in Multi-Dwelling and IR Zones.” Title 33 Planning and Zoning, City of Portland, 1 March 2020, https://www.portland.gov/code/33/600s/612. Accessed 14 Feb. 2021. “33.613 Lots in Commercial/Mixed Use and CI Zones.” Title 33 Planning and Zoning, City of Portland, 24 May 2018, https://www.portland.gov/code/33/600s/613. Accessed 14 Feb. 2021. “33.720 Assignment of Review Bodies.” Title 33 Planning and Zoning, City of Portland, 10 Aug. 2020, https://www.portland.gov/code/33/700s/720. Accessed 26 Feb. 2021.