Er is behoefte aan meer woningen. (There is a need for more housing.)
behoefte takes "aan" (behoefte aan = need for). Example: Er is behoefte aan meer woningen. (There is a need for more housing.)
Er is behoefte aan meer woningen. — There is a need for more housing. The preposition aan is fixed, so it doesn't change with the sentence.
Fixed prepositions come up all over the A2 exam. The platform drills them in real exam tasks, AI-graded across all five DUO sections.