Pacific Northwest Research Station

PORTLAND, Ore. March 10, 2008. Any realtor will tell you that trees can increase the value of a home, but by how much? A recent study addressed this question by quantifying the impact of street trees on Portland’s housing market.

The study was conducted in 2007 by research forester Geoffrey Donovan of the Forest Service’s Pacific Northwest Research Station and David Butry of the National Institute of Standards and Technology, U.S. Department of Commerce. “We measured the trees in the public right of way outside of 3,479 houses in Portland that sold between July 2006 and March 2007,” Donovan says, “after controlling for differences in house and neighborhood characteristics, we found that the number of street trees directly fronting a house and canopy cover within 100 feet of the home both positively influenced house price.”

Key findings of the study are:

• On average, street trees add $7,020 to the price of a house in Portland, which is equivalent to increasing the size of a house by 106 square feet.
• Street trees increase the value of homes in Portland by a total of $1.1 billion, which is equivalent to annual benefits of $45 million.
• The annual maintenance costs of Portland’s street trees are $4.6 million ($3.3 million is borne by the homeowner), so the benefit-cost ratio of Portland’s street trees is almost 10 to 1.
• Street trees increase annual property tax revenue for the city of Portland by $13 million.

Geoffrey Donovan is giving a presentation on his research findings Monday, March 17, 12:00 noon to 1:00 p.m., in the Portland Building auditorium, 1120 S.W. 5th Avenue. The event is free and open to the public. Donovan’s paper, “Trees and the City: Estimating the Value of Street Trees in Portland, Oregon, Using Hedonic Evaluation,” has been submitted for publication to the journal Land Economics and Arborist News.