As climate change increasingly influences urban life, cities across the U.S. grapple with the challenge of providing housing while preserving and expanding their tree canopies.
Trees play a crucial role in mitigating climate effects; they provide cooling shade, absorb carbon emissions, and help manage stormwater runoff to reduce flooding risks.
However, in the rush to build more homes efficiently, many developers view trees as obstacles.
This conflict has reached a critical point in Seattle, where recent legislation mandates increased housing density without necessarily protecting tree cover.
A notable attempt to resolve this issue is the Bryant Heights development, located in northeast Seattle, which showcases how to accommodate both dense housing and trees.
Developers worked in collaboration with architects Ray and Mary Johnston to transform a once underdeveloped city block into a vibrant community featuring a mix of apartments, townhouses, single-family homes, and retail spaces.
The design incorporated 86 housing units where only four previously existed while maintaining the integrity of existing trees.
Mary Johnston emphasized their philosophy during the design process: “The first question is never how can we get rid of that tree, but how can we save that tree and build something unique around it.”
This commitment led to the preservation of over 30 mature trees, including Douglas firs, cedars, oaks, and Japanese maples.
One standout is a towering deodar cedar that measures more than 100 feet tall and boasts a canopy exceeding 40 feet in diameter.
Ray Johnston highlighted the benefits of this particular tree, which not only cools adjacent buildings with its shade but also absorbs air pollutants and acts as a gathering space for residents.
“In essence, it’s like another resident, really — it’s like their neighbor,” remarked Mary Johnston.
Preserving such trees required negotiations with city authorities to ensure new construction would not harm them.
The developers agreed to use porous concrete for walkway areas beneath the tree to facilitate water infiltration to the roots.
Instead of opting to remove the tree for additional building space, the enlightened developer prioritized preservation.
Seattle’s urban environment is currently facing a housing crisis, necessitating the construction of thousands of new homes each year.
Recently, the city council revoked single-family zoning rules, mandating that all urban neighborhoods accommodate a minimum of four units per lot.
To protect trees on private property during developments, Seattle updated its tree protection ordinance, originally enacted in 2001.
According to Megan Neuman, manager of land use policy and technical teams with the Department of Construction and Inspections, the new tree code aims to preserve the city’s tree canopy during housing expansions.
“It’s about finding that balance between housing and trees while growing our canopy,” Neuman stated.
Despite the city’s efforts, recent assessments indicate that Seattle’s tree canopy has shrunk by approximately 0.5% between 2016 and 2021, translating to roughly 255 acres of loss.
This reduction is comparable to the expansive Green Lake park and represents a significant decrease in neighborhoods and natural areas, which have seen canopy losses of 1.2% and 5.1%, respectively.
Seattle is proactively addressing these challenges by intensifying tree planting initiatives in parks, natural areas, and public regions, although hurdles remain.
New legislation mandates that the city must ensure proper care for planted trees, including watering and mulching during their crucial initial growth stages to help them withstand increasing heat in summers.
The updated tree protection laws also stipulate that developers must replace any removed trees, requiring three new trees to be planted for every one that is taken down.
The goal is to achieve a tree canopy coverage of 30% by the year 2037.
Developers generally support Seattle’s updated tree protection ordinance, noting that it offers increased predictability and flexibility compared to prior regulations.
Many developers, including Cameron Willett, director of city homes at Intracorp, view the new code as a sensible strategy that allows the coexistence of housing and trees.
Willett acknowledged that the code permits increased tree removal when necessary while concurrently mandating more replacement planting and building around preserved trees.
Though he recognizes that some projects may involve complicated negotiations to save trees, he believes that the outcomes justify the extra effort.
“Trees make better communities,” Willett affirmed.
He added that meaningful actions to balance development and tree preservation are essential for community welfare amidst growing urban density.
Nonetheless, organizations like Tree Action Seattle express concerns regarding developments that appear to sacrifice too many trees for housing.
This ongoing tension became particularly evident during the intense heat dome that impacted the Pacific Northwest in the summer of 2021.
“Hundreds of people died, many of whom would likely have survived if temperatures hadn’t soared so high,” noted Joshua Morris, conservation director of the nonprofit Birds Connect Seattle.
Morris emphasized that neighborhoods with more greenery tend to have significantly lower temperatures.
He highlighted Seattle’s South Park neighborhood, which is experiencing one of the lowest tree canopy coverage rates in the city at merely 12%-15%.
Research indicates that life expectancy in South Park is, on average, 13 years shorter than in greener areas due to environmental conditions exacerbated by nearby pollution sources.
In a proposed development in South Park, plans indicate that the construction of 22 new units will lead to the removal of three large evergreens and several smaller trees.
However, Morris believes that slight adjustments to the building layout could allow the preservation of all slated trees, along with the potential addition of more.
While Seattle’s revised tree code permits tree removal, larger trees now come with restrictions that require developers to incorporate on-site replacements or contribute to reforestation funds aimed at restoring greenery in neighborhoods like South Park.
Tree advocates warn that new saplings will take years to grow, offering far less environmental benefit compared to established trees that help mitigate carbon emissions right now.
Morris expressed concern that these actions resonate with the notion of “death by a million cuts.”
Cities across the nation, including Nashville, Portland, and Charleston, are experiencing similar tree losses.
According to Vivek Shandas, a geography professor at Portland State University, if municipalities fail to act decisively, they risk further shrinking their existing tree canopies.
Shandas argues that current municipal codes do not adequately address climate change ramifications.
He calls for proactive measures to safeguard urban tree canopies, which are essential for providing shade and managing rainfall runoff due to the changing climate.
Shandas contends that as construction strategies focus on maximizing lot use, urban heat intensity and flooding risks will likely increase.
With climate change leading to growing temperatures and rising sea levels, Shandas fears that existing building codes may fall behind, resulting in inadequate protective measures for trees.
How developers engage with evolving codes in Seattle will be crucial over the coming decades, especially concerning the role of trees in facilitating community adaptation to climate change.
With increasing average temperatures and stagnant cooling nights, the need for well-distributed trees is becoming more urgent than ever.
Architects Ray and Mary Johnston tout examples of innovation in tree-inclusive design, such as their Boulders development in Seattle, which centers around a preserved 40-year-old Scotch pine.
This project converted a single-family lot into nine townhomes while integrating salvaged mature trees from other projects into its landscape.
Mary Johnston highlights that building with trees in mind may lead to lower utility bills.
“Units with proper tree cover require less air conditioning, resulting in cost savings for residents,” she noted.
Ray Johnston advocates for city codes that incentivize creating shaded, verdant spaces as climate change progresses.
Living in shaded environments is undoubtedly preferable to stark, heat-prone urban areas devoid of greenery, he stated.
In sum, Seattle’s ongoing battle between housing development and tree preservation illustrates a critical crossroads for urban planning amidst a climate crisis that requires thoughtful collaboration and innovative practices.
image source from：https://www.opb.org/article/2025/06/15/tree-preservation-housing-demand-climate-solution/
