Translation:There are many rooms in the new American houses.
Hungarian uses van in "to have" constructions, but van doesn't mean "to have". Those constructions are pretty specific with "[Owner]-nak van [possession]-ja" ("For the owner there exists their possession") and you neither have a -nak suffix nor a possessive marker in this sentence.
Then again, I probably should be more liberal with my assessment of translations. Hungarian doesn't have a word to the ubiquitous "to have", but just because of that I shouldn't disregard valid translations. So feel free to decide for yourself. :´)