The Hansen's are norwegians, though I don't know where in Norway their family comes from. Guess the west-coast or north in Norway. Im myself are from the south-east in Norway.
I hear they speak some norwegian on the show, but the accent got alot of english/american accent in to it. I tried to hear what dialect they have, but it was impossible for me to conclude what dialect they got on their norwegian.
One thing I guess, Sig's full name are "Sigurd" or "Sigbjørn" witch are typical norwegian names. Just look at their last name, "Hansen", it's almost the most common surname in Norway. And Edgar and Edgard is also common.
One thing is sure, the Hansen's make me proud of being a norwegian.