Residential home and neighboring ADU MEP plan

We have full house plans for a 3500 sq ft custom post and beam / stick build hybrid house and a nearby 1000 sq ft ADU with 3 car garage under it. Especially with post and beam, the electrical, plumbing, and HVAC need to be planned. In addition, we would like to do a bit of external rendering and interior placement of furniture, light switches, ceiling fans etc., to make sure it all works. I am an engineer and have reasonable building skills and will give written guidance (marketed up 2D plans in PowerPoint). We are looking to get that converted to a fairly simple MEP plan that the builder and his subs can work from, so we do not have any major miscommunications.