I was on the Hannover.de website today and thought this may interest someone in the local Toytown Community.

It looks like the City Council offers a discount of 10% (per child) up to a max of 40% for those families purchasing building plot for a single family home or dwelling.

here is the link to the English brochure.
http://www.hannover.de/data/download/lhh/wirtschaft/HaKiBaBo_E.pdf