In 2015, Seattle added approximately 22,400 people to a estimated population of 662,400. This is a rate of nearly 1,867 per month or 62 people per day. This is only Seattle proper, many more people are settling in the surrounding areas.
The question is, where are all those people going to live? Seattle is experiencing one of the tightest home markets in history with few homes available for the surging demand. A balanced real estate market would be a supply of 4-6 months worth of homes for the demand. We are currently around a 1 month supply.
Puget Sound Business Journal article