The program shows 4 couples who have 77 days to build and model an apartment.
The couples win the difference between this value and the start-value, which the apartment had, before they started the renovation.
Couples will go through various contests to see who will build which apartment, and who will eventually be asked to leave.
The 4th season, running from September 2007, shows a new location as Het Blok has moved to Haarlem.
Supposedly the series has returned to its original format, leaving out the surprises that were introduced in the third season.