The legal position is that the agreement between yourself and the designer dictates ownership of the drawing copyright and thus ownership of the planning drawings and associated files. If the terms of engagement do not assign copyright in any particular party, copyright is owned by the author ie the designer. This is the case where you have not discussed or agreed copyright ownership. At a minimum, your payment of the designers fees for the drawing will imply a licensing of the drawings to you and possibly to any essential parties for the construction of your project. This might be satisfied by the delivery of the drawings in PDF and/or printed media.
Similarly, with respect to the 3D CAD, the designer is usually the owner by reason of being the originator. In the absence of specific guidance in your terms of engagement, the designer has no contractual obligation to provide you with a copy of the CAD files.
When you appoint efkor, the terms of engagement are clearly set out. The planning drawings and CAD files are owned by efkor and the client has a free lifetime licence for their use in connection with the project. efkor will provide a one set of printed A3 drawings at no extra charge. The CAD files are available for unlimited download for 12 months after the end of the contract with efkor.