In a study of sold homes on the east side of Portland, a new report says street trees add an average of $8,870 to sales prices and reduce time-on-market by almost two days.
The report, which will be published in Landscape and Urban Planning, is the first of its kind to examine the “effect of urban trees on the housing market” by explicitly focusing on street trees. Co-authors, Geoffrey Donovan of the Portland Forestry Sciences Laboratory and David Butry of the National Institute of Standards and Technology, also published a valuation report on street trees last year with the east side of Portland as its test sample.
Both reports used data collected during the summer of 2007, when 3,479 single-family homes—every home sold in a 10-month period—were visited for detailed evaluations.
Algorithm factors gathered include: sale price; distance to downtown; distance to nearest park; house age; tree type; tree size; and many more.
While the equations include a swath of data variables for each home and street tree, the concluding message is singular: “In Portland, the benefits of street trees significantly outweigh their maintenance costs,” wrote Butry and Donovan.
In dollars and square footage, the average canopy coverage of 904 square feet found at a home created a resale value equivalent to an additional 129 square feet of finished house, according to the report. Applying that average effect to the 126,176 east side houses yields a total value of $1.12 billion.
With the return of investment on street trees comes the responsibility of Portland home owners to plant and do maintenance. Planting with Friends of Trees, a city of Portland partner with the Grey to Green Initiative (G2G), lessens the burden on home owners via discounted nursery prices and community planting practices.
In an effort to enhance Portland’s urban canopy and simultaneously absorb carbon emissions and storm runoff, G2G has a goal of planting 83,000 street and yard trees over five years.
According to the report, there are approximately 236,000 street trees in Portland, with a 26 percent canopy cover.