The Boulders advancement, integrated in 2006 in Seattle's Green Lake neighborhood, includes a mature tree in addition to a waterfall. The developer likewise added mature trees salvaged from other advancements - placing them tactically to add texture and cooling to the landscaping. Parker Miles Blohm/KNKX hide caption

Climate change shapes where and how we live. That's why NPR is dedicating a week to stories about services for building and living on a hotter planet.

SEATTLE - Across the U.S., cities are struggling to stabilize the requirement for more housing with the need to maintain and grow trees that help resolve the impacts of environment modification.

Trees supply cooling shade that can save lives. They soak up carbon contamination from the air and reduce stormwater runoff and the danger of flooding. Yet lots of contractors perceive them as an obstacle to quickly and effectively installing housing.

This stress between development and tree conservation is at a tipping point in Seattle, where a brand-new state law is requiring more housing density however not more trees.

One solution is to find ways to develop density with trees. The Bryant Heights advancement in northeast Seattle is an example of this. It's an extra-large city block that includes a mix of modern homes, town houses, single-family homes and retail. Architects Ray and Mary Johnston dealt with the developer to place 86 housing systems where as soon as there were 4. They likewise saved trees.

Architects Mary and Ray Johnston conserved more than 30 trees in the Bryant Heights development they worked on. Parker Miles Blohm/KNKX conceal caption

"The very first question is never ever, how can we eliminate that tree," explains Mary Johnston, "but how can we save that tree and develop something distinct around it." She points to a row of town homes nestled into two groves of mature trees that were in location before construction began in 2017. Some grow mere feet from the new structures.

The Johnstons protected more than 30 trees at Bryant Heights, from Douglas firs and cedars to oak trees and Japanese maples.

One of Ray Johnston's favorites is a deodar cedar that's more than 100 feet tall. The tree stands at the center of a group of apartment structures. "It probably has a canopy that is close to over 40 feet in diameter," he notes.

This cedar cools the nearby structures with the shade from its canopy. It filters carbon emissions and other contamination from the air and acts as a gathering point for citizens. "So it's like another citizen, actually - it resembles their next-door neighbor," Mary Johnston states.

Preserving this tree required some additional negotiations with the city, according to the Johnstons. They had to show their new building and construction would not hurt it. They needed to accept use concrete that is permeable for the sidewalks underneath the tree to enable water to leak down to the tree's roots.

The developer could have quickly chosen to take this tree out, along with another one close by, to fit another row of town houses down the middle of the block. "But it never came to that because the designer was informed that way," Ray Johnston states.

Preserving some trees in Bryant Heights needed additional negotiations with the city of Seattle. Special concrete that is porous was used for the walkways underneath specific trees, enabling water to seep down to the trees' roots. Parker Miles Blohm/KNKX hide caption

Housing pushes trees out

Seattle, like many cities, remains in the throes of a housing crunch, with pressure to include countless new homes every year and increase density. Single-family zoning is no longer permitted; instead, a minimum of four units per lot should now be allowed all urban neighborhoods.

The City board recently updated its tree security regulation, a law it initially passed in 2001, to keep trees on personal residential or commercial property from being reduced throughout advancement.

"Its baseline is protection of trees," states Megan Neuman, a land use policy and technical teams manager with Seattle's Department of Construction and Inspections. She says the new tree code consists of "limited circumstances" where tree removal is enabled.

"That's actually to attempt to help find that balance in between housing and trees and growing our canopy," Neuman states. Despite the city's efforts to preserve and grow the metropolitan canopy, the most recent assessment showed it shrank by an overall of about half a percent from 2016 to 2021. That's comparable to 255 acres - a location approximately the size of the city's popular Green Lake, or more than 192 regulation-size American football fields. Neighborhood property zones and parks and natural areas saw the greatest losses, at 1.2% and 5.1% respectively.

Seattle states it's working on several fronts to reverse that trend. The city's Office of Sustainability and Environment says the city is planting more trees in parks, natural locations and public rights of method. A new requirement indicates the city likewise has to take care of those trees with watering and mulching for the first 5 years after planting, to ensure they survive Seattle's progressively hot and dry summers.

The city also says the 2023 update to its tree defense regulation increases tree replacement requirements when trees are removed for advancement. It extends defense to more trees and needs, in many cases, that for each tree got rid of, three must be planted. The objective is to reach canopy coverage of 30% by 2037.

Developers normally support Seattle's latest tree defense regulation because they state it's more predictable and flexible than previous variations of the law. Many of them helped shape the new policies as they deal with pressure to add about 120,000 homes over the next twenty years, based upon development management preparation required by the state.

Cameron Willett, Seattle-based director of city homes at Intracorp, a Canadian realty developer, sees the existing code as a "common sense technique" that permits housing and trees to coexist. It allows home builders to lower more trees as required, he states, but it also requires more replanting and enables them to construct around trees when they can. "I certainly have projects I have actually done this year where I've secured a tree that, under the old code, I would not have actually had the ability to do," Willett states. "But I have actually also had to replant both on- and off-site."

Willett recalls one advancement this year where he preserved a fully grown tree, which needed proving that the site could be established without harming that tree. That likewise implied "additional administrative complexity and costs," he describes.

Still, Willett states it's worth it when it works.

"Trees make much better communities," he states. "We all wish to conserve the trees, but we also need to be able to get to our max density."

But Tree Action Seattle and other tree-protection groups regularly highlight brand-new advancements where they say too many trees are being taken out to make way for housing. This tension follows a devastating heat dome hovered over the Pacific Northwest in the summer season of 2021. "We saw numerous individuals die from that, hundreds of individuals who otherwise would not have died if the temperature levels had not gotten so high," says Joshua Morris, preservation director with the not-for-profit Birds Connect Seattle. He served six years as a volunteer advisor and co-chair of the city's Urban Forestry Commission, which provides competence on policies for conservation and management of trees and plant life in Seattle.

Joshua Morris, preservation director with the not-for-profit Birds Connect Seattle, served 6 years as a volunteer adviser and co-chair of Seattle's Urban Forestry Commission. Parker Miles Blohm/KNKX hide caption

"We understand that in leafier neighborhoods, there is a considerably lower temperature than in lower-canopy communities, and in some cases it can be 10 degrees lower," Morris says.

Making area for trees

Seattle's South Park neighborhood is one of those hotter areas. Residents have roughly 12% to 15% tree canopy protection there - about half as much as the citywide average. Studies reveal life span rates here are 13 years shorter than in leafier parts of the city. That remains in large part due to air pollution and pollutants from a neighboring Superfund website.

In a cleared lot in South Park, 22 new units are going in where once 4 single-family homes stood. Three huge evergreens and numerous smaller trees are anticipated to be lowered, says Morris. But with some "slight rearrangements to the setup of structures that are being proposed," Morris speculates, "a designer who has done an analysis of this website reckons that all of the trees that would be slated for removal could be retained. And more trees could be added."

Tree eliminations are enabled under Seattle's upgraded tree code. But getting rid of larger trees now requires designers to plant replacements on-site or pay into a fund that the city prepares to use to assist reforest areas like South Park.

In Seattle's South Park neighborhood, citizens have about half as much tree canopy as the citywide average. Four single-family homes once based on this lot, where 22 new systems will quickly be constructed. Plans filed with the city reveal three big evergreens and a number of smaller sized trees that are still standing on the lot are slated for removal. Parker Miles Blohm/KNKX conceal caption

Groups such as Tree Action Seattle point out that these new trees will take several years to develop - compromising years of carbon mitigation work when compared with existing fully grown trees - at a vital time for suppressing planet-warming emissions.

Morris says the trees that will likely be lowered for this development may not seem like a big number.

"This really is death by a million cuts."

He says trees have been cut down all over the city for many years - thousands per year.

"At that scale, the cooling result of the trees is lessened," says Morris, "and the increased risk of death from excessive heat is heightened."

Building codes aren't staying up to date with climate change

Tree loss is not limited to Seattle. It's occurring in lots of cities throughout the country, from Portland, Ore., to Charleston, W.Va., and Nashville, Tenn., states Portland State University location professor Vivek Shandas. "If we do not take swift and extremely direct action with preservation of trees, of existing canopy, we're visiting the whole canopy shrink," Shandas states.

He says current community codes do not effectively resolve the ramifications of environment modification. The Pacific Northwest, Shandas states, should be getting ready for increasingly hot summer seasons and more intense rain in winter season. Trees are required to supply shade and soak up runoff.

"So that development entering - if it's lot edge to lot edge - we're visiting an amplification of metropolitan heat," Shandas states. "We're going to see a higher quantity of flooding in those areas."

Climate change is heightening typhoons and raising sea levels while likewise contributing in wildfires. Such extreme conditions are outpacing building codes, describes Shandas, and he fears this will happen in the Northwest too.

Shandas states how designers react to the structure codes that Seattle adopts over the next 20 to 50 years will identify the degree to which trees will assist individuals here adapt to the warming environment.

That matters in Seattle, where the nights aren't cooling down nearly as much as they used to and where average daytime highs are getting hotter every year.

The Bryant Heights development is a contemporary mix of houses, town houses, single-family homes and retail. Architects Ray and Mary Johnston worked with the designer to position 86 housing units where there were at first four. Parker Miles Blohm/KNKX hide caption

An option in the style

Architects Ray and Mary Johnston see part of the solution at another Seattle advancement they designed around an existing 40-year-old Scotch pine.

The Boulders development, near Seattle's Green Lake Park, changed a single-family lot into a complex with 9 town homes. The designer included mature trees he restored from other advancements - transplanting them tactically to include texture and cooling to the landscaping.

Mary Johnston says structure with trees in mind could also help individuals's wallets. Boulders, she states, is an example. "Since these systems have air conditioning, those costs are going to be lower since you have this type of cooler environment," she says. Ray Johnston states places like this dubious urban oasis must be incentivized in city codes, specifically as climate modification continues.