[1] The farmhouses have the features of all Frisian houses: the walls are made of red brick and have a thatched roof and white or blue window frames and doors.
This meant that in the event that one of the huge coastal storms, that regularly batter the area, badly damaged the roof and walls, the internal structure continued to provide its occupants with some protection.
Because cattle farming and sailing were the main means of livelihood in the areas concerned, large store rooms for the harvest were not needed.
Because islands and Halligen were largely treeless, marine debris, such as ships' masts and planks washed up on the shore, was used for the internal timber frame.
Haus Olesen, originally built in 1617, was demolished and rebuilt in Wyk auf Föhr, and is now the oldest preserved house of this type.