I learned this when my company leased the floor of a big office building in Philly. You can do almost anything you want, except for with plumbing. Especially bathrooms. Despite having almost 150 desks there is a limit of 3 sinks, 6 stalls, 2 urinals, and 6 hand washing sinks. Full stop.
I wonder what causes these buildings to have such restrictions on plumbing. Maybe it's like elevator shafts where they eventually take up a lot of space if the building is very tall.
It's more an issue of volume. People showing, doing laundry, cooking etc use significantly more water, so the pipes entering and leaving the building need to be sized differently.
Conversely, adding more toilets, for example, may also pose a challenge. My dad helped design the plumbing system for a rebuild of a football stadium. One of the final tests was to have a bunch of volunteers go to every sink, toilet and urinal in the building and turn them on / flush them simultaneously to ensure that water pressure stayed high and the drain pipes didn't back up.
Adding more toilets in a building not meant for them can be a big deal right after lunch / around "busy" times... Some may not be able to flush or overflow if the pipes can't handle the extra activity.
I didn’t get that involved but was told it wasn’t a matter of cost. There were very limited hookups that could be moved slightly for the sinks. Bathrooms could not be moved or modified in any way. I assume it’s a limit on the overall building in/output.
There were very limited hookups that could be moved slightly for the sinks.
This means you couldn't chip up the concrete slab to place new pipes, the way we could in e.g. a strip mall. This is an understandable limitation, because the integrity of slabs is important for tall buildings.
However, this wouldn't be a limitation in a residential remodel. They aren't going to mess with the slab or the pipes in it. They're just going to lay everything over the top of the slab. If the new toilet is 40' from the utility shaft, that is 3" for the pipe plus 5" for the fall. Add an inch for the floor itself. Average residential ceilings are much lower than average office building ceilings, so there is definitely at least 9" to spare.
