Piping in block wall

Greetings. I am designing plumbing for a commercial kitchen, the architect is giving me a hard time about chases. I have several lavs backed up to hollow core block walls. I have never designed piping in block walls in the past because the local code did not allow it. They have now adopted the 2011 IPC and I don't see anything prohibiting this.
Does anyone have any other info? Is this allowed? Does the piping need to be installed as the block is laid? Does metallic piping need to be coated if in hollow core without concrete fill?

Thanks

I worked as an auto mechanic a good portion of my life. Around 1980 I was working for a friend in a leased service station. One very cold night in the winter the oil burning furnace quit. We came in next morning and found the plumbing had froze and there were numerous broken pipes. The water meter was the first broken item and once that was repaired I worked my way around the building fixing each break as I found them. The bathrooms were last on the list. They were typical gas station small bathrooms on the outer perimeter of the building. The copper pipes had been run thru the block walls and there was at least one break inside those blocks I could not access.......I cut off the water supply and capped it from inside the building. The only way a repair could have been done was to break out the block and replace the pipe run.So the point of my long winded story is copper plumbing inside block walls is not a good idea if you are in a cold climate in the winter....at least not from my experience!

In this area, we install pipes in block walls all the time. Whether half the block is left out until the piping is finished, or the block slid down over it, depends on how the piping has to be configured.

I am trying to wrap my mind around how piping is installed in the block. Do they make an 8" block that is missing one face so a channel can be left in the block until after installation?

Otherwise, the mason and the plumber have to work together side by side to install the pipes, supports, insulation, rough-in connections, etc etc as the wall goes up. We've got copper water dropping from the ceiling, and PVC DWV.

The lavatories in this case are stainless steel wall mounted and will also have to be attached to the block. The walls are all interior so we don't have to worry about freezing.

Because of timing and testing, the walls and plumbing cannot go up at the same time. Usually the plumbing is installed and then the mason blocks up both sides using "wafers" without a web between them, or they can cut the block's webs to fit around the pipe. Hanging the lavatories to the concrete block will be a complicating factor which has to be addressed since the block will have to be solid enough to support them.

I have done a few buildings and have always installed the plumbing exposed on the opposite side of the wall in a pipe chase. I know this creates a wasted space but the piping will last longer and when repairs are required they can be completed. usually there is a access door to access the pipe chase from one side or the other.
Just my 2 cents worth