The NOP was only formed in 1942, when the last dyke was closed and the drainage could start. The Germans didn't mind young men working in the NOP (the last dyke was closed in the middle of WWII), since they also realised the need for new agricultural areas to feed the people. By the end of the war, there were several worker's camps in the polder, where young men lived in relative freedom. They had to dig ditches, build roads, plant trees and whatever else was needed to make this polder habitable.
After the war ended, those camps continued to exist, but with more and more land 'done up', there was more need for houses than baracks. However, a lot of people needed housing in the Netherlands and materials to build houses wasn't always easy to come by. Part of the problem was then solved by the Austrian government who donated houses to the NOP. Austria of course had been (a willing?) part to the German Third Reich and wanted to make amends.
These houses can be found in the main town/village of Emmeloord, two of the larger villages (Marknesse and Ens) and even next to the oldest farms. Made of wood, they are still quite a sight in the NOP, since the houses in the Netherlands are usually made of brick.