Property Values 11 Times Higher Across Portland's Urban Growth Boundary

One of the starkest impacts of smart growth policies is the huge differentials in property prices that occur on virtually adjacent properties on either side of an urban growth boundary.

The extent to which regulatory restrictions can drive up prices is illustrated by the differences between the values of undeveloped lands just a few steps from each other, but across the urban growth boundary. Research from more than a decade ago in Portland indicated that land on which development is permitted inside the urban growth boundary tended to be 10 times as valuable per acre as land immediately outside the urban growth boundary, on which development was not permitted. In Auckland, New Zealand, recent research found virtually adjoining undeveloped land value differences at 10 times or more as well. Research in the London area by Dr. Timothy Leunig of the London School of Economics indicates that this difference can be as much as 500 times.

Recently (February), I examined tax assessment records for all parcels in Portland's Washington County that abut the urban growth boundary to see if value differences exist. The properties had to be 5 or more acres and be undeveloped. Research was conducted based upon Internet information in February 2010. Property along 25 miles of the urban growth boundary from Cedar Hills to Hillsboro to southwest Beaverton was included in the analysis.

  • The land adjacent to, but outside the urban growth boundary (on which development is prohibited) was assessed at approximately $16,000 per acre.
  • The land adjacent to, but inside the urban growth boundary (on which development is permitted) was assessed at approximately $180,000 per acre, approximately 11 times the price of land that is virtually across the street (across the urban growth boundary)

A sample was also taken of more remote developable parcels of more than 5 acres, on which development would not be permitted. These parcels, which were from one to five miles outside the urban growth boundary, had a value of approximately $8,500. Thus, the developable land inside the urban growth boundary was 21 times as expensive as the more remote land.

These data indicate the impact of urban growth boundaries on the price of raw land, which is inevitably passed on to buyers of new housing. Without an urban growth boundary, it would be expected that land on both sides of an urban growth boundary would have similar values. Further, land would be expected to drop in value beyond the urban fringe, but not by the drastic amounts indicated in Portland, Auckland and London.


Photograph: (By Author)