New draft Ratio Studies standard exposed

IAAO releases new ratio studies exposure draft, requests feedback on revised version

May 1, 2026 – A new, updated draft of the Standard on Ratio Studies has been released to IAAO members for comment and feedback during a 30-day exposure period starting May 1.

Updates to the IAAO’s Standard on Ratio Studies were last approved in 2013. In 2025, the Research and Standards released an initial rewrite of the standard, which was the culmination of several years of collaboration. Following the release, the committee conducted an extensive outreach campaign, which included three Fair+Equitable articles, a conference presentation, an episode of the Assessing the Situation podcast, and two webinars.Based on comments received, the committee made substantial revisions to the draft standard and is seeking comments on the revised draft. In April, the IAAO Board of Directors approved releasing the exposure draft for comment.

The Research and Standards Committee is requesting members review the results of their work, and, more importantly, to provide feedback, which is highly valued.  The 2026 Exposure Draft feedback form is available below.

There were significant changes to the draft, particularly in the area of vertical equity, along with updates to the COD Standard Ranges, and substantial revisions to the appendices, including new appendices. A summary of changes made to the first draft is available online.

*** Feedback is requested by May 31 ***

The Exposure Draft represents the committee’s work and is not to be considered a final document.  The 2013 version remains the recommended guidance until a final version, edited to reflect stakeholder feedback, is approved by the IAAO Board.