Housing Affordability Index

  1. Overall Housing Affordability Index
  2. First-Time Buyer Housing Affordability Index

Data Tables


The Housing Affordability Index (HAI) tracks the ability of a middle-income family to afford the mortgage payments on a median-price home. An index of 100 reflects a balance between the family’s ability to pay and the mortgage payment. Higher indices indicate that housing is more affordable.

Thurston and nearby counties' HAI have been generally decreasing since 2013. Currently, none of Thurston's nearby counties are considered affordable for overall homebuyers. From the first quarter of 2022 to the first quarter of 2023, Thurston County's HAI decreased 22 percent. The HAI for King, Lewis, and Pierce counties is even lower, meaning middle-income households in those counties will have an even harder time finding housing they can afford to buy.

2013 was the last year buying a home in Thurston County was considered affordable for first-time homebuyers.

First-time Buyer Housing Affordability Index

The first-time buyer index assumes the purchaser’s income is 70% of the median household income. Homes purchased by first-time buyers are 85% of area’s median price. All loans are assumed to be 30 year loans with 25% of income used for principal and interest payments. The overall buyer index assumes 20% down. The first-time buyer index assumes 10% down. 


University of Washington: Runstad Center for Real Estate Studies