Absent specific agreement to the contrary, the copyright in these files resides with the Engineer; so he is probably within his rights.
The Engineer's policy makes some sense for him. I have seen situations where clients of mine sent out CAD plans to customers and those customers made their own amendments to the drawings. This is a liability mess for the professional: he\she can only stand over amendments made by him\her, and it is too risky to have other versions in circulation..
That said, if you just want\need to be able to print off copies as needed, ask him to send you the drawings in pdf format. These will not be editable (and you need to be careful scaling off them), but at least you can print them as needed.