Either you have received a letter from the Bezirksamt (district office) or flyers from the network of Heimstaden houses. If you have not yet received a letter, but are noted on this card, it is relatively certain that your house is part of the Heimstaden package.
To be absolutely sure, please contact the district groups of the Heimstaden Network or the Grundbuchamt (land registry). They can tell you for sure who owns the house. However, it is possible that the purchase has not yet been registered.