Mire en español | 用西班牙語觀看  |  Xem bằng tiếng Việt

The Housing Hillsboro project aimed to help meet the needs of our community now and in the future. The adopted code amendments allow for more housing choices that are accessible, affordable, and fit the diverse needs of our residents.

In addition, Housing Hillsboro reduced regulatory barriers, encouraged middle housing development, and brought the City's regulations and procedures into compliance with House Bill 2001, the statewide law that required cities to allow middle housing such as duplexes, triplexes, and cottage clusters to be built in areas traditionally zoned for single-family homes.

Hillsboro City Council adopted the draft amendments at their May 17, 2022 meeting with minor changes. Adopted amendments are incorporated in Subchapter 12 of the City of Hillsboro Development Code and went into effective June 30, 2022.

Read the Frequently Asked Questions.

Middle Housing 

Middle housing is designed to accommodate more residents than single-family homes, but less than large multifamily complexes. Nearly every single-family zone in the City allows some form of middle housing. The City’s regulations aim to maintain the look, feel, and scale of the surrounding neighborhood while allowing for a variety of housing options.

• Learn about the different types of middle housing in the State of Oregon's Housing Choices Guide Book.
• Type your address into our Hillsboro Maps tool to see what types of housing development are currently allowed in your neighborhood.
• Learn which zones in Hillsboro currently permit each middle housing type below.

---

Duplex 

A duplex is a middle housing type with two separate attached or detached dwelling units on a lot with their own entrances. 

Currently, duplexes are permitted in the SFR-4.5, SCR-LD, SCR-DNC, and Multi-Family residential zones, depending on density and minimum lot size requirements, and in many Mixed-Use zones. Duplexes may also be constructed in limited cases in large subdivisions in the SFR-10, SFR-8.5, SFR-7, and SFR-6 zones.

Triplex and Quadplex

• A triplex is a middle housing structure with three distinct attached or detached dwelling units on one lot.
• A quadplex is a type of middle housing that contains four attached or detached dwelling units on one lot. 

Currently, triplexes and quadplexes are considered “multiple dwelling structures” and are permitted housing types in SCR-DNC and Multi-Family residential zones, depending on density and minimum lot size requirements, and in many Mixed-Use zones.

Triplexes and quadplexes may be constructed through the Planned Unit Development process in the SFR-10, SFR-8.5, SFR-7, SFR-6, SFR-4.5, and SCR-LD zones.

---

Townhouse

Also commonly referred to as a “row house,” this housing type is characterized by attached units each on a separate lot and its own entry from a public or shared street or common area.

Currently, two-unit townhouses are considered similar to duplex dwelling units and permitted in the same residential zones (see above).

Townhouses with three or more dwelling units are permitted in the SCR-LD, SCR-DNC , and Multi-Family residential zones, and in many Mixed-Use zones. In lower density Single-Family Residential zones, these larger townhouses may be constructed through the Planned Unit Development process.

Cottage Cluster

According to HB 2001, a cottage cluster is no fewer than four detached dwelling units per acre with a footprint of less than 900 square feet each that includes a common courtyard.

This housing type is currently not recognized in the Community Development Code.

Accessory Dwelling Units (ADUs) are small, secondary housing units constructed on the same property as a single-family house.

ADUs have been allowed on single-family residential lots in Hillsboro since the 1990s. In early 2020, the Community Development Code was amended to ease architectural standards and remove the off-street parking requirements.

Hillsboro is currently in compliance with HB 2001 requirements for ADUs. Staff will look for additional ways to reduce regulatory barriers for ADUs.

To reduce the impact of flooding on communities, the Federal Emergency Management Agency (FEMA) requires communities to manage development in floodplains and publishes maps of floodplains. The City’s regulations for development in the 1% annual chance floodplain are contained within the Regulatory Floodplain Overlay (RFO).

It is the City’s responsibility to enforce current standards for development to participate in the National Flood Insurance Program. This program provides flood insurance to property owners, renters and businesses within the 1% annual chance floodplain.

Code Update

The Department of Land Conservation and Development (DLCD) released a new Oregon Model Flood Hazard Ordinance in 2020, developed in cooperation with FEMA. The amendment folded the model ordinance language into the City’s existing code, ensuring that all minimum standards are met and any existing higher standards specific to Hillsboro are retained.

In addition, the amendment evaluated existing permit procedures and made recommendations on where the process could be refined. For example, substantial improvements to existing structures currently require a Type III Floodplain Activity permit which involves a public hearing. This is a technical review and a discretionary hearing is not necessary.

Timeline:

• January to April 2025: Draft Code Amendment
• April 23, 2025: Planning Commission Work Session
• May 14, 2025: Planning Commission Public Hearing
• June 2025: City Council 1st and 2nd Reading

For more information, please contact Rachel Marble at Rachel.Marble@Hillsboro-Oregon.gov.

The Significant Natural Resource Overlay (SNRO) implemented Statewide Planning Goal 5 which requires an inventory and protection for natural resources including significant wetlands, riparian corridors, and wildlife habitat.

While the standards provide protection for the resources, they also balance conservation with reasonable economic use of the land.

Code Update

During this limited technical update, Planning Division staff evaluated SNRO code standards to ensure that they are clear and objective. There was not any changes to what is allowed or permitted within this overlay, nor were there changes to the amount of mitigation required if the SNRO is encroached upon. Staff refined and simplified the code so that it is understandable and concise for both developers and property owners.

The language was adopted by Council in August 19, 2025, and the ordinance is now in effect.

For more information about the Significant Natural Resource Overlay code amendment, please contact Rachel Marble at Rachel.Marble@Hillsboro-Oregon.gov.

The Community Development Code (CDC) was adopted by City Council in August 2014 and is updated on an ongoing basis. In August 2025, the Council adopted the following amendments to create consistency for street cross-sections and help City staff assess the distribution of Transportation Development Tax credits.

Code Updates

Amberglen Plan District

The CDC Amberglen Plan District has street cross-sections with sidewalks, planter strips, and multi-use paths that are wider than what is typically constructed within the City.

The large-scale amenities provide an attractive and comfortable environment for residents, pedestrians, and bicyclists living in the high-density neighborhoods. However, the scale of the required public improvements has impeded redevelopment, and has increased land use approvals needed for small reductions to CDC standards. Some recent examples include, reducing a 12 foot sidewalk with tree wells to 10 feet, and a 24 foot multi-use path being reduced to 16 feet.

This CDC amendment scales the code requirements to be consistent with what has been approved and constructed in Amberglen, while maintaining that consistency for future development.

It also corrects missing details, and creates consistency, with Public Works Design and Construction standards. The amendment increases clarity for Amberglen property owners, developers, review authorities, and City staff. 

South Hillsboro Plan District

Figure 12.65.930-A of the CDC for the South Hillsboro Plan District is missing the identified cross-section reference number for SE Murphy Street between SW 229th Avenue and SW 209th Avenue.

The updated figure assigns a cross-section reference number.

Witch Hazel Village and Witch Hazel Village South Plan Districts

The Witch Hazel Village Community Plan was adopted 25 years ago. The revisions to CDC Section 12.67 Witch Hazel Village Plan District updates the area map to reflect the updated street layout and modernizes the bicycle facilities on City roadways.

When the Witch Hazel Village South Plan District was adopted into the CDC in 2023, City staff planned to update it once the City engineering work for the area was completed. The revisions within CDC Section 12.68 match the work the City has done in ensuring a well-connected multimodal system.

Transportation Procedures

The changes to CDC Section 12.70.200 Transportation Studies clarifies sections that caused confusion for land use applicants and provides additional guidance regarding when a Traffic Management Plan and a Traffic Impact Analysis is required. The additional details improve clarity of the CDC requirements. The CDC amendment was also updated to the current edition of the Highway Capacity Manual.

Timeline

• July 9, 2025: Planning Commission Public Hearing
• August 5 & 19, 2025: City Council 1st and 2nd Readings
• September 19, 2025: Code Language Effective 

For more information, please contact Ruth Klein at Ruth.Klein@Hillsboro-Oregon.gov.

In 2023, Planning Division staff amended code language to better facilitate utility undergrounding and provide clearer paths for projects of different scales.

The adopted approach divided development proposals into three categories, each with different requirements concerning utility undergrounding:

The Community Development Code (CDC) was adopted by City Council in August 2014 as Ordinance No. 6094 and is maintained on an ongoing basis. Planning staff keeps a record of amendments needed to keep the document updated. Those amendments are brought forward regularly as omnibus amendments.

Proposed Code Update

The proposed amendment would incorporate various policy neutral changes and conforming amendments to ensure consistency with state legislation to the Hillsboro Community Development Code.

Timeline

• September 24: Planning Commission Initiation
• October 8: Planning Commission Public Hearing
• October 21: City Council 1st Reading
• November 4: City Council 2nd Reading