Could I get in trouble with copyright if I draw up a blue print and build the house that I see on the internet?

Yes unless the print you saw was knowingly distributed as free by the copyright holder or of the print was old enough to have an expired copyright. Just because you see it on the internet does not mean you can take it.

Your question isn't completely clear to me, but I suggest that you look up Architectural Copyright and review Circular 41 available from the Copyright Office.

If you are copying an original work that has not been dedicated to the public or exceeded the term of its copyright, you may then be infringing the copyrights of the owner of architectural drawings. You may also be liable under copyright law for any architectural structure (a derivative work) constructed from your copied drawings. The color of the drawings has no bearing on copyrights. Depending on whether to owner of the drawings has registered his/her copyrights in the drawings, you might also be liable for attorney's fees in an infringement action.