This does deviate a bit from the specific 1070 discussion, but I'll reiterate something that we have to tell clients in our industry at times: there is no such thing as a perfect set of plans. We're human, as are the people interpreting our drawings and building what we design - and if it an existing structure being modified, the same applies to the people who designed and built it originally. It really is effectively impossible to guarantee perfect coordination between all aspects of such a design. Modern electronics are a lot smaller than a modern building, but they routinely pack in just as much complexity - if not more in some cases. The goal of good design is to minimize the potential errors, get as close to right as you can, and try your damndest not to ever make the same mistake twice.