Trees for Life Oregon’s Call for Tree Code Changes in the Upcoming Revision Process

August 2026

Portland’s Urban Forestry has already officially begun its Title 11 (tree code) revision project. Community engagement will start between now and winter 2027, and in spring and fall of next year the public will have opportunities for input through commission hearings. After Council amendments, that body will approve the revised code. 

For climate resilience, shade equity, and public health reasons, we’ve been arguing for a more robust tree code which, except for a few positive amendments, hasn’t been revised since its implementation, in 2015. To strengthen Title 11 protections for existing big-tree canopy plus space to plant more large shade trees, we have already shared with City staff our list of “asks,” and we have started to lead tree code walks for interested City Councilors.

Here’s what we’re asking for, below. Please sign up on our homepage to receive our call for action alerts—the best way to learn when, how, and where to have your voices heard during this code revision project.

Trees for Life Oregon’s Priority Tree Code (Title 11) Changes and How to Align Canopy Protections Across Other Codes and Bureau Practices

Preface: It’s not only Title 11 that governs trees. Trees are impacted by other codes, administrative rules, and multiple bureau practices as well. This is why we believe only an integrated approach that aligns all the various City codes and rules affecting trees will be effective in protecting, preserving, and expanding Portland’s tree canopy to meet our climate crisis. Note that our priorities further below are separated into Title 11, followed by the specific codes, rules, and practices in other bureaus that affect tree canopy.

Title 11, Trees

■ Modify the exemption based on lot size for trees in development situations. Reduce the lot size that is exempt from Title 11 tree preservation from <5,000 square feet to < 3,000 square feet. Most of Portland’s residential properties are under 5,000 square feet (see map created by Urban Forestry in 2024), which means that most of them are not subject to the tree code. These higher density areas need trees for shade and livability.  This amendment would be more equitable as well. The developers of smaller lots should contribute to preserving and replenishing Portland’s tree canopy, along with developers of larger lots. Developers of lots smaller than 3,000 sf could remain exempt from the standards but could be required to pay into the City’s mitigation fund for trees removed. 

■ Eliminate the exemption for properties in the IH (heavy industrial) zone for trees in development situations.  The recent Economic Opportunities Analysis scenarios demonstrated that Portland will have sufficient future industrial land supply, even when assuming that Title 11 exemptions from tree preservation were removed. Therefore, it is now time to apply these standards to development in IH zones so that those projects will contribute to preserving and replenishing Portland’s tree canopy along with developments in other zones.    

■ Remove the exemption for affordable housing projects. Affordable housing residents need trees just like everyone else and probably more so.  Compared to wealthier Portlanders, these residents likely have less income, less time or means to travel to distant parks or natural areas, and are less likely to have air conditioning. A commitment and incentives to support creative tree/housing integrative design will go a long way to shade these residents in hot summers. It’s already been done elsewhere and in Portland, for instance, by New Columbia Apartments. The builder who razed the original houses on that site took care to preserve as many healthy, mature big trees as possible. 

■ Remove or modify the exemption for properties in zones allowing 85% building coverage. Similar to our recommendation to remove the exemption from tree preservation standards for properties in the IH zone, it would be appropriate and more equitable to explore approaches for developers in high-density zones to contribute to preserving and replenishing Portland’s tree canopy. (Blue on the map above shows sites where 85% or more building coverage is allowed.) Options could include incentives for preserving larger trees/space for trees, and/or paying into the City’s tree mitigation fund for trees removed. 

■ Account for and mitigate the loss of large-form trees in development situations.  Title 11 does not currently require or adequately encourage planting of large- or medium-size trees in development situations.  The Title 11 update should pursue, where viable, amendments that require or encourage the planting of development sites with large- or medium-size non-nuisance species trees. One option might be to require or incentivize the replacement of large-form trees that are removed in development situations with other large-form non-nuisance species. In development situations, these invasive trees, in particular, should be required to be removed—tree of heaven (Ailanthus altissima), English holly (Ilex aquifolium), European birch (Betula pendula), and cottonwood (Populus alba L.).

■ Explore and pursue approaches to ensure or encourage that when private trees are removed in non-development situations they be replaced with large- or medium-size trees where feasible.  The trend in Portland is to replace with smaller trees when large trees die naturally or are removed. Large-form trees provide significantly greater benefits than smaller trees do. 

■ It is critical that any potential code amendments retain consistency between provisions for trees in development and non-development situations. Otherwise, there is the potential to create loopholes that, for example, could create an incentive to cut trees before submitting a development application. 

■ Tie heritage tree protection to the space these trees occupy. When heritage trees die and are removed, preserve that space to plant new large-form trees.  If homeowners know that once a heritage tree is removed they must plant another tree in that space, it eliminates the temptation to hasten the heritage tree’s end of life to replace it with, say, a parking space or patio. In fact, throughout the tree code, link trees to the space they need to grow. 

■ Amend the Title 11 section on the Urban Forestry Commission. In future we anticipate proposing revisions here.

PBOT Code and the Pedestrian Design Guide

■ Make it quick and easy to modify sidewalk configurations to preserve trees and space for trees. The Portland Bureau of Transportation’s standard for straight sidewalks reduces many opportunities for preserving space for trees. Currently, developers who wish to preserve a large, mature private-side tree next to a sidewalk are penalized for doing so by being required to apply and pay for a variance for curving a sidewalk around a shade-giving tree. Incentivize preservation of these trees through automatic, cost-free variances if the stated purpose is to preserve a private-side healthy, non-invasive tree, and other accessibility requirements can be met.

■ Increase from 4 feet to 6 feet the mandatory minimum planting strip width for new ROW trees in the Pedestrian Design Guide. PBOT’s current Pedestrian Design Guide gives developers the option of creating 6-foot-wide planting strips but does not mandate this. More than half of Portland’s tree canopy is located on private property. Trees planted in the ROW have more secure protection than trees in private yards do.

Title 33, Zoning Code

■ Identify and pursue approaches to address trees earlier in the development application process. One option could be to have tree permitting and regulation staff now in the Portland Permitting and Development Bureau require submittal of tree plans in conjunction with early assistance meetings with developers. Consider mandating such meetings for more types of projects. 

■ Mandate minimum permeable space for trees on development sites and require that this space be preserved in perpetuity. We are very concerned about the proliferation of impervious surfaces in the city, which worsens heat and flood risk. Let’s start here: In the zoning code, “outdoor area” can be paved. Title 33.110.240.C.2 (p, 56) states that outdoor area “must be surfaced with lawn, pavers, decking, or sport court paving which allows the area to be used for recreational purposes. User amenities, such as tables, benches, trees, planter boxes, garden plots, drinking fountains, spas, or pools may be placed in the outdoor area. It may be covered, such as a covered patio…”[bold by TFLO]  Life-giving trees are rated as “amenities,” equivalent to outdoor tables. And few trees can grow in a covered area. Installing a deck or pool into permeable surface space renders it an impervious surface, leaving no or scant space for shade trees.

■ Current requirements for multi-family dwellings preclude room for large-form trees on site, a scenario that disadvantages those residents’ health (Urban Forest Plan, p.7). There needs to be discussion about how to mitigate for that, for example, by creating nearby clean-air tree reservoirs.

Public Works

Revisit these bureau standards, which limit space for trees at a time the City is trying to increase canopy. We have never heard justification for these standards: 

■ The Bureau of Environment Services’ standard is that a 10-foot easement is needed around sewer lines, and that trees cannot be planted within 10 feet of these lines. 

■ The Water Bureau’s standard that trees must be 10 feet from 24-inch water mains has done a great deal of harm to City projects such as the SE Division redesign several years ago. Hundreds of trees were to be planted along a tree-deficient corridor, but the Water Bureau prevented that from happening, and nearby residents were outraged. Urban Forestry staff worked with the Water Bureau in 2023 to provide on-the-ground evidence that trees and water pipes can safely co-exist with less than 10 feet between them, but to our knowledge this standard has not been changed.