The population in Washington State has reached 8 million people and is forecast to reach 9 million by 2038. According to the Department of Commerce, we need to build 1.1 million housing units by 2044 to keep up with the population growth. More half of those will "need to be affordable for residents at the lowest income levels."
According to the Washington State Office of Financial Management, the annual growth of housing units has ranged between 46,000 and 47,000 per year since 2020.
If this rate holds, Washington State will be adding between 920,000 to 940,000 new housing units over the next 20 years. That’s a deficit of 160,000 to 180,000 housing units over the next 20 years, or between 8,000 to 9,000 units per year. 718,900 of the needed housing units, or about 65%, must be built in just 4 out of 39 counties: Clark, King, Pierce, and Snohomish. With over $35 billion in below-market-rate federal loans available, some of that extra demand may be met by commercial-to-residential conversions. However, if that target is not reached, rents may climb across the state, especially in the 4 biggest counties.