Just show him the picture and your email to the designer.
Sometimes I wonder if some GC's do things solely with the bottom-line in mind.
If this is important and it does sound like a big part of the ambiance of the home, then you need to speak up.

"the beam was meant to be below the ceiling and was to have drywall on it making a large cased doorway"

I read this just like the builder did. If you needed a load bearing wall, the beam would be located below the ceiling and would support it. the bottom of the beam would make the top part of the door casing. With trusses, load bearing walls are often unnecessary. So when the builder frames the wall, he will frame the door way with a header over the door that is part of the wall structure. Does that make sense?

Your builder isn't wrong, He's just approaching it as a structural element and not considering the cosmetic aspect that you want.Since it isn't structural,you can ask him to simply frame up a false beam since you want it drywalled,and it can be the size you are after by framing it accordingly.

This is the plan. The beam is question appears as a dotted line between the greatroom and kitchen/eating area.

Here is a link that might be useful: house plan

Without a plan showing the truss layout and framing I don't know who is right. Why not ask the designer if the beam is a structural item.

(I really wish more people would invest the typical $500-$1,000 that a P.E. would charge to vett a simple house plan.)

The beam appears to be the same width as the rest of the framing lumber and since it will be sheetrocked anyway, it does not need to be a beam, but a header. Since it spans a good distance it will be rather stout...possibly an engineered beam supported on each end by those walls that are on your plan or maybe a double 2x10 with a sheet of OSB inbetween them. But it will still be part of the wall framing and not there to hold up the ceiling that is above it. Personally, I'd be inclined to leave the area open between the kitchen/dining area and the livingroom and forget the beam (or header in this case) all together. If you want it there, tell the builder that you want it even though it is not required for structural reasons. Tell him you want some definition between the two areas instead of the open floor plan that you would end up with if the beam or header was left out.

Worthy,

For those of us who are a bit acronym challenged, exactly what kind of an engineer is a P.E. anyway? And, how would yor recommend I go about finding one to hire? I would be quite happy to pay to have a P.E. (whatever that is) vet my house plans if that would avoid future arguments with my builder.

Thanks,

P.E. = Professional Engineer, sometimes called Registered Professional Engineer. Specified levels of experience plus satisfactory scores on a battery of tests are necessary for the PE designation. My son is a PE and has a Master's degree. Since there are several different types of engineers, an electrical engineer typically would not deal with structural issues, for example. But the integrity of the engineer should serve to self-limit the practice to the areas of true expertise. My son limits himself to piping systems.

More than likely, the truss manufacturer has already done the engineering to make sure the trusses can span the entire distance with no load bearing walls in the middle. Ask them just to be sure. My own house is 28' wide with clear span trusses.....no load bearing walls in the center at all. my sunroon is 47' long and those trusses are supported only on the ends. If your builder is using trusses, then it is very unlikely you need any load bearing beams in the middle. At this point, the beam is strictly there to divide the space.

Sorry. Structural engineer who is a PE.

ccoombs1 has a good idea. Truss companies, in my experience, have a P.E. who reviews their designs.

yep...around here if you use trusses, the county permitting office doesn't even question the inner part of the house, just the foundation and outer walls. That's how I was able to get away with designing my own house without getting an engineer involved. The truss company designed the trusses to span the distance I needed them to span and no load bearing walls were required. Sure made my life easier!