Once a manufactured home has left the factory, U.S. Department of Housing and Urban Development codes do not include provision for alterations and additions.

Be advised that making modifications to a factory-built house may jeopardize your home warranty. Making changes can also compromise the structure, possibly making the home unsafe.

You may need permits for any approved additions that are freestanding structures, even if they meet building codes. Talk to your manufacturer, the state agency overseeing manufactured housing, HUD, or other local building officials for more information.