Stephpi, you're floor plan is very very similar to mine and I have HAH. In fact the linen closet in the foyer going into your MB is the same approximate location of one of my outlets.I placed it in that closet along with all of the implements so it would not have to be located on a long open more visible wall.

Is your house going to have a full basement? I ask because we are doing HAH and we also have a very open first floor. The piping for the first floor outlet runs down into the basement. It makes one sweeping 90 degree turn, goes about 15 ft., makes another sweeping 90, goes another 15 ft., hits the last sweeping 90 and runs about 20 ft back into the center of the house. After you have enough pipe to fit the hose, you can use traditional 90s and 45s to get the feed back to the vacuum unit. For the second floor outlet, they took the pipe into the attic and have basically the same configuration.

Our builder has also never used HAH. We met with his central vac guy and explained that we wanted HAH. He basically gave us the same response your builder gave you. We went onto the HAH website and found a certfied installer in our area. He knew exactly how to make everything work with our layout. Our builder is anxious to see how everything works. I would see if you can find someone in your area who has experience with HAH.

My installer hid/piped 60 feet of hose between the garage and the next room over...... there is about 15 ft between the motor and the outlet. In our case (1 story,) the piping runs into the attic space and then back down again.

I am not an expert, but I would suggest contracting with a local HAH installer in your area. (I am in a relatively smaller area, but there are still multiple installers here.)

Both ours are routed in the attic. This was done by the certified installer. No mention of needing a long wall.

We installed ours ourselves. Our first floor hose is 'garaged' between the first floor ceiling and the second floor. The second floor hoses (2) are 'garaged' in the attic. The piping has to be long enough to accommodate the length of each hose and should only have sweeping bends so that hose moves easily through them. The pipes then drop down the walls to the outlet. It's not difficult.
It sounds as though your builder is trying to put the HAH 'garage' in the wall! It should go in the ceiling or attic with just a short run in the wall to the outlet.

The only situation I can imagine a problem would be a house built on a slab and with no attic - but then there would probably be a lot of other problems with that setup.

Thanks everyone! I just copied and pasted your replies in an email to my builder. I also asked him if his electrician was talking to a HAH rep or a central vac rep because it doesn't sound like he knows what he is talking about with a 30' wall!! I just KNEW that couldn't be right.

Yes, we will have a full unfinished basement. Sounds like we should have no trouble as long as I make sure a to get the right HAH person installing. I am feeling much more encouraged about this whole situation.

Thanks so much HAH internet friends!! :-)

We have a house on a slab with no attic...and HAH.

We ran both runs for the upstairs and downstairs pipe runs in the second floor joists and some pipe also went into an area of dropped ceiling in our MBR. It was a slight challenge, mostly in just finding someone to put the pipes in. I made sure it was done to specs and so far it is working great.