Study: House Sizes Increase at the Expense of Tree Canopies

A research study has found that increasing house sizes in the Los Angeles area have drastically reduced the number of trees shading the region's landscapes—regardless of geographic location of socioeconomic status.

2 minute read

May 3, 2017, 12:00 PM PDT

By James Brasuell @CasualBrasuell


Hollywood Blvd

Andrey Bayda / Shutterstock

Researchers with the USC Spatial Sciences Institute, led by Su Jin Lee, Professor Travis Longcore, Catherin Rich, and John P. Wilson have published a study finding that green cover for single-family home lots declined anywhere from 14 to 55 percent the Los Angeles area, with almost no single area spared from decline.

The study was published in the journal Urban Forestry & Urban Greening and announced in a press release on EurekaAlert.

As noted in the study, much of the "de-greening" of Los Angeles occurred as the city implemented a "Million Trees" campaign. The researchers began by taking an inventory of single-family parcels in the largest 20 largest cities in the Los Angeles basin, starting with the parcels that had added square footage to the home since 2007.

Baldwin Park led all areas in reduction, seeing a 55 percent loss of green cover on single-family residential lots in the mere span of nine years.

Other areas in the study that had at least 20 percent loss in cover included Pomona, Downey, Sylmar, Compton, and San Pedro/Port of Los Angeles.

The study noted one prominent exception: Pasadena, which maintained its verdant condition.

"[Study author] Longcore believes changing social views on the preferred size of single-family homes is the largest driver of tree cover loss, along with the increase in paved surfaces like walkways, driveways and swimming pools that come with home expansion," according to the press release.

Monday, May 1, 2017 in EurekAlert

Young Professional

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban and Environmental Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban and Environmental Planner

Get top-rated, practical training for planners

"Planetizen federal action tracker" logo superimposed over black and white image of US Capitol dome.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

September 16, 2026 - Zachary Whalen

Passengers board an Amtrak train under a cloudy sky.

Amtrak, CN end decades-long dispute with eight-year agreement

The new operating agreement establishes an updated framework for the companies to work together, including processes to resolve disputes.

September 18, 2026 - Mass Transit

The Gross Reservoir, a large body of water surrounded by trees and mountains.

Judges permit Denver to divert 77,000 acre feet from the Colorado River for reservoir expansion

Overuse and climate change have caused the Colorado River’s water levels to plummet.

September 18, 2026 - Inside Climate News

A painted bus lane in NYC.

NYC DOT wants faster, more permanent street upgrades

The city is examining ways to build more concrete infrastructure without getting entangled in 'decades-long' projects.

September 21 - NYC Streetsblog

A woman looks at a utility bill.

'Something we’ve never seen before:' rising utility rates could strain city finances nationwide

Data centers, climate change and other factors have caused utility rates in the United States to increase by 38% since 2020.

September 21 - Smart Cities Dive

A person scuba diving in a coral reef off Guam.

Trump to overrule local leaders, lease millions of acres of America’s Pacific Island territories’ seafloors to mining companies

International law says that the Indigenous people of America’s territories have a right to prior and informed consent regarding projects that impact their countries.

September 21 - Grist