| Rank | County | Housing Units | 
                            
                                
                                    | 1 | King County, Washington | 854,703 | 
                            
                                
                                    | 2 | Pierce County, Washington | 327,228 | 
                            
                                
                                    | 3 | Snohomish County, Washington | 289,151 | 
                            
                                
                                    | 4 | Spokane County, Washington | 203,159 | 
                            
                                
                                    | 5 | Clark County, Washington | 168,403 | 
                            
                                
                                    | 6 | Thurston County, Washington | 109,965 | 
                            
                                
                                    | 7 | Kitsap County, Washington | 108,364 | 
                            
                                
                                    | 8 | Whatcom County, Washington | 91,280 | 
                            
                                
                                    | 9 | Yakima County, Washington | 85,904 | 
                            
                                
                                    | 10 | Benton County, Washington | 69,580 | 
                            
                                
                                    | 11 | Skagit County, Washington | 51,945 | 
                            
                                
                                    | 12 | Cowlitz County, Washington | 43,607 | 
                            
                                
                                    | 13 | Island County, Washington | 40,731 | 
                            
                                
                                    | 14 | Chelan County, Washington | 35,870 | 
                            
                                
                                    | 15 | Clallam County, Washington | 35,827 | 
                            
                                
                                    | 16 | Grant County, Washington | 35,473 | 
                            
                                
                                    | 17 | Grays Harbor County, Washington | 35,261 | 
                            
                                
                                    | 18 | Lewis County, Washington | 34,387 | 
                            
                                
                                    | 19 | Mason County, Washington | 33,033 | 
                            
                                
                                    | 20 | Franklin County, Washington | 25,120 | 
                            
                                
                                    | 21 | Walla Walla County, Washington | 23,584 | 
                            
                                
                                    | 22 | Okanogan County, Washington | 22,527 | 
                            
                                
                                    | 23 | Kittitas County, Washington | 22,297 | 
                            
                                
                                    | 24 | Stevens County, Washington | 21,481 | 
                            
                                
                                    | 25 | Whitman County, Washington | 19,435 | 
                            
                                
                                    | 26 | Jefferson County, Washington | 18,020 | 
                            
                                
                                    | 27 | Douglas County, Washington | 16,187 | 
                            
                                
                                    | 28 | Pacific County, Washington | 15,644 | 
                            
                                
                                    | 29 | San Juan County, Washington | 13,671 | 
                            
                                
                                    | 30 | Asotin County, Washington | 9,919 | 
                            
                                
                                    | 31 | Klickitat County, Washington | 9,891 | 
                            
                                
                                    | 32 | Pend Oreille County, Washington | 8,078 | 
                            
                                
                                    | 33 | Adams County, Washington | 6,325 | 
                            
                                
                                    | 34 | Lincoln County, Washington | 5,834 | 
                            
                                
                                    | 35 | Skamania County, Washington | 5,696 | 
                            
                                
                                    | 36 | Ferry County, Washington | 4,466 | 
                            
                                
                                    | 37 | Columbia County, Washington | 2,141 | 
                            
                                
                                    | 38 | Wahkiakum County, Washington | 2,080 | 
                            
                                
                                    | 39 | Garfield County, Washington | 1,223 |