Yamhill County assessor explains Measure 50, change property ratio and how redevelopment can shift McMinnville tax rolls

Derek Wharf, Yamhill County assessor, told the McMinnville City Council at a work session that Oregon’s property-tax rules created by Measure 50 and the annual change property ratio (CPR) drive how new construction and redevelopment are added to the tax rolls.

Wharf said three values — real market value (RMV), maximum assessed value (MAV) set under Measure 50 in 1997, and the assessed value (the lower of RMV and MAV) — determine what is taxable. He explained that the CPR is calculated from the gap between RMV and MAV on existing properties by property type; that percentage is then applied to new construction in a given year to set the MAV for that new construction.

The assessor used examples and a $15 million multifamily case to show how phased construction is added to the roll and how different CPRs produce very different taxable values: “If in 2024 the CPR for multifamily was 0.5 and we put on $9,000,000 then $4,500,000 would go on the MAV line,” Wharf said. He noted multifamily CPRs had fallen sharply in recent years — he cited multifamily CPRs down to about 0.35 in 2024–25 and single-family CPRs in the 0.5–0.6 range, from highs near 0.85–0.9 earlier in the decade.

Why it matters

Wharf told councilors that exception events — new construction, loss of a tax exemption, a change in use or zoning, or a major remodel — trigger recalculation of MAVs using the CPR in the year the event occurs. That can create winners and losers depending on market timing: a property converting from an exempt use to taxable use could see a sharp increase or decrease in assessed value depending on current CPRs and RMV.

Councilors asked several questions about specific local projects. Wharf said public acquisition in an urban renewal area removes both the incremental increase above the frozen base and the underlying frozen value from the taxable roll while the property is publicly owned and exempt. He gave the example that the county’s recent purchase of the OMI property produced a fully burdened tax bill for the prior year but will not be taxable for tax year 2025–26 because it is now publicly owned. He said the same July 1 timing rules apply generally: an exempt status on July 1 remains for the tax year; an acquisition after July 1 is not exempt until the next tax year.

Northwest Rubber, redevelopment and affordable housing

Councilors pressed on how redevelopment at sites such as Northwest Rubber would be treated. Wharf said redevelopment is an exception event that will be CPRed in the year it occurs; if the city or a nonprofit retains ownership and the use is exempt, the taxable portion can be reduced or eliminated. If private developers build and occupy, the new construction will be valued and taxed according to that year’s CPR and MAV calculations. Wharf noted specific affordable-housing programs can produce different tax outcomes: some local programs require city adoption and local application processes and can produce exemptions or different taxable treatments; others are statewide or federal programs with separate rules.

CPR mechanics and construction-in-progress

Wharf explained how the assessor treats construction in progress for large projects: the office estimates percent complete on January 1, applies that portion of the project’s RMV through that year’s CPR to establish MAV increments, and repeats the process each January 1 until the project reaches completion. He said some large commercial projects may qualify for a two-year construction-in-progress exemption under statewide statute (he did not cite a code section), and industrial exemptions such as enterprise zone or strategic investment programs are handled differently and may require local approval.

Councilor questions and local numbers

Councilor Cunningham asked specific CPR figures. Wharf said single-family CPRs were “running at 0.5, almost 0.6” and multifamily CPRs had “dropped to 0.35 in 2024–25,” citing the rapid rise of RMV for multifamily (driven by rising rents and the income approach to valuation) as a key cause. Councilor Chenoweth asked whether affordable-housing components built by private developers would automatically be tax-exempt; Wharf answered that qualifying for local exemption programs requires local adoption and an application process, and some low-income housing program assessments use separate taxable formulas rather than full exemption.

What the council heard

Councilors and staff used the session to clarify how tax outcomes would change if the city acquired property inside urban renewal, sold public land, or moved forward with redevelopment that included a mix of taxable and exempt uses. Wharf recommended that the council and staff coordinate closely with the assessor’s office early in redevelopment planning to understand the tax consequences of ownership, use, and phasing.

Ending

The council thanked Wharf and said staff would follow up with additional questions about specific projects. Wharf offered to provide more detailed, project-level calculations if the city supplied development scenarios and timelines.