This will depend on exactly how you conduct your business. But, in general, you will probably need to file for a business license or DBA. This is because most home builders are required to offer a warranty on work. So, even if you hire a subcontractor who pulls all the permits and does all the work, you will be the one required to fulfill any obligations under that warranty. And, as a homebuilder, you will almost definitely need to file your business paperwork with the state or local government.