"All 21 counties now have an average price over 1 million kronor and that's the first time this has happened, I believe," Martin Verhage at Statistics Sweden's (SCB) told The Local.
Verhage said the developments were a surprise to the researchers, but pointed out that over the past two years, house prises in Sweden have crept up 2 percent nationwide.
House prices increased in 17 out of 21 counties when compared to 2011. The counties that saw the biggest growth included Blekinge, Norrbotten and Uppsala - all of which shot up by 6 percent in 2012.
Decreasing house prices, meanwhile, were reported in three counties. The largest being in Gotland by 4 percent, followed by Kalmar at 2 percent.
As for the nation's most populated counties, prices in Greater Gothenburg and Greater Stockholm increased by 4 and 3 percent respectively, while prices decreased in Greater Malmö by 1 percent.
Sweden's highest average home price was in Stockholm, at just over 3.7 million kronor, with Västernorrland the lowest at just over 1 million kronor.