Is it ok to ask for drawings in a land that is for sale?

[David Sotomayor]

Hello Guys. I probably have an unprofessional question but: 

So it will be our first large investment. This land is being sold with designs and drawings of townhomes that are allowed to be built. So my question is, is it ok, or professional, or legal, to request a copy of the drawings, something basic, to start doing my own due diligence of soft costs with contractors and architects? would the realtor be able to provide that, or they would basically sell it to me stamped? i just need an almost clear view of how much would each townhome cost after building etc, and get the loan as well.