Oregon Revised Statutes Cities § 227.290

(1) The council or other governing body of any incorporated city, under an exercise of its police powers, may establish or alter building setback lines on private property adjacent to any alley, street, avenue, boulevard, highway or other public way in such city. It may make it unlawful and provide a penalty for erecting after said establishment any building or structure closer to the street line than such setback line, except as may be expressly provided by ordinance. The council or body shall pass and put into effect such ordinances as may be needed for the purpose of providing for a notice to and hearing of persons owning property affected before establishing any such setback line. Such setback lines may be established without requiring a cutting off or removal of buildings existing at the time.

(2) The council may consider, in enacting ordinances governing building setback lines, the site slope and tree cover of the land with regard to solar exposure. The council shall not restrict construction where site slope and tree cover make incident solar energy collection unfeasible, except an existing solar structure's sun plane shall not be substantially impaired.

(3) The council may consider, in enacting ordinances governing building setback lines and maximum building height, the impact on available wind resources. The ordinances shall protect an existing wind energy system's wind source to the extent feasible.

(4) The powers given in this section shall be so exercised as to preserve constitutional rights.