Sheet metal HVAC contractors play a pivotal role in the construction process - directing numerous instrumental parts during a symphony performance. However, since sheet metal HVAC firms don't always precisely fit the definition of "mechanical" contractor, they sometimes fall into the category of "sub"
Ironically, during the construction process, it's often the sheet metal HVAC contractor's CAD program and CAD drawings that lead and orchestrate the project - directing the timing and placement of ductwork, air handling equipment, plumbing, electrical, drywall, etc.
Fortunately, things are changing. Today, many sheet metal contractors who perform Design/Build work have the opportunity to sit at the table with the owner and/or general contractor (GC). Several years ago, SMACNA (Sheet Metal and Air Conditioning Contractors' National Association) members reported they were hired by a general contractor 48% of the time, by the building owner 36%, by the mechanical contractor 31%, and by the construction manager 23% (the numbers don't total 100% because the surveys allowed contractors to answer multiple questions).