As  a professional 3D modelling service provider we hear quite often these words and questions:

• do we really need a visualisation of the project?
• it’s too expensive to make a 3D model, we’ll manage with 2D drawings
• we’ve have managed so far without 3D models quite good
• ….and all other reasons

just a one sample series of pictures will show how fast can you understand the design and make a fast visual check will all fit in or not.
Comparing to construction time and cost making a 3D model is just a blink of an eye and cost almost nothing!

My answer is obvious! It is not a question.  You need to visualise!