Q : Enterprise License on 3D Building Design

Hello My name is Leone and my company(System Integration company) are currently considering the use of UE4 to develope a 3D CAD system especially for a Plant design.
Our project will import BIM & Equipment data from Revit and 3DS Max and deploy MEP(Mechanical, electrical, and plumbing) elements and pre-registered Equipment Models by our customer company’s designers

So in this project, Buyer is the customer company and the price of the program will be depends on the contract(like how much support or educations are needed…ETC.)

what i want to know is

  1. this kind of software developement is on enterprise licensing? or should we pay royalty for this project?
  2. what kind of support contract are existed on enterprise license support and how much will it be cost?

Thank you for reading and hope to get a reply soon.

I believe everything you are looking for is in the
UNREAL® ENGINE END USER LICENSE AGREEMENT EULA - Unreal Engine
You may also want to look at the UE4 Enterprise page (and videos on their YouTube Channel) Other licensing options - Unreal Engine

Short answer:
You agree to pay Epic a royalty equal to 5% of all worldwide gross revenue actually attributable to each Product, regardless of whether that revenue is received by you or any other person or legal entity,

Epic does not have any support obligations with respect to the Licensed Technology under this Agreement. Support resources may be obtained at unrealengine.com/faq.