Raised/false floors for plumbing

I was just checking over the new Willow Feeder page and was reminded of something. Due to the nature of having a bucket under your seat, they both have raised floors or steps.

We built a small community house last year that included 2 bathrooms. The original design was pretty standard with all the plumbing & pipes buried in the floor. We found this pretty bad because we kept making small changes to the design & layout as we learned more about our needs, as we built. But if all your stuff is in the floor, you can't ever get to it again! Heck, if it starts leaking after a year, how would you even know? There's a toilet sitting on top of flooring on top of a subfloor. Sometimes interior walls are sitting on the subfloor, so you'd have to bust out a saw to even check. Or you put trap doors everywhere for checking lol. I suppose this is why people have crawlspaces.

But the obvious answer for us was, why not just build a slightly raised floor instead, and put all the pipes in there? I suppose it could be "less stylish" and confusing to a normal home owner, but I see no downside to having to step up 1 or 2 steps to get into the bathroom, or onto the toilet/shower. Then you can have all your plumbing above floor level, easily accessible, easy to check on, easy to fix.

We are planning on doing this once we put a full shower in the second bathroom.

Anybody have experiences with or thoughts on this?

Sure it's all been done. A couple of my oilfield skid shack houses had raised plumbing floors. Been done in remodels as well. Also prevents freezing in an obviously movable structure.
The door is a bit of an issue, on top of raised floor or in front of raised floor? You'd want/need a landing outside of the door to prevent someone stumbling out and down at the same time in the dark through the door.
If you are not building on a slab, then your floor should have had a ventilated crawl space under it for sure. I'm guessing you also have no building inspectors involved or yours is pretty low.
There are no leaks....... right? Why pressurized piping is always continuous in inaccessible spaces. ABS drains will never leak in your lifetime.
Water supply can also come from overhead, then only drains are affected.
Another issue is the rigidity, false floors tend to be kinda weak sounding/feeling. Subfloor glue helps, under framing and holding subfloor down to framing.

Usually all the plumbing is in the walls.  Why put plumbing in a raised floor?

Anne Miller wrote:Usually all the plumbing is in the walls.  Why put plumbing in a raised floor?

Toilet drains go down.
Always. Pretty sure. Basements were not part of OPs question.
Only your upstairs neighbor has a toilet drain passing through your wall. Vents, of course, always rise through a wall. In wall one way vent caps can be used where a riser is not practical.

In places that never freeze, most plumbing could be in an exterior wall. Carving a drain line through a wall stud doesn't leave much framing meat for stiffness. Plumbing tends to be in 2x6 walls. Walls can be doubled or furred out for additional room. Soffits can be added to conceal overhead horizontal pipes.
Codes have requirements, based on common sense, and experience about the length of in wall laterals for drains and number of turns allowed, and the requirement for cleanouts.

Standard toilets do flush down.
Most commercial toilets go into the wall.
These use pressure instead of gravity ,to flush.
They require a large supply line, like 1" or bigger.
There are probably exceptions to this, toilets that add pressure some other way.
If not, a pump could be rigged to do this.

Or, a crawl space could be used.
Gravity is very reliable.
I live in Cincinnati, where basements are the the default, at least in the city proper.
I used to think no house should be built without a basement.
Now I think that preventing settling is the most important foundation issue.

Settling foundations will break plumbing lines, no matter what kind of foundation it is.
I think lines coming up vertically into the middle of a foundation might be more resilient than any that come in the side of a foundation.

William Bronson wrote: Standard toilets do flush down.
Most commercial toilets go into the wall.

Do they then stay in the wall?? Or do they then also go down at some point?

Commercial units go horizontal for a very brief run into a wet wall, where they also go....
Down.
Pretty sure.
Built more than a few commercial buildings.
Either way, the problem is the same. If you stubbed your plumbing up through a floor or slab, and then change your mind......
Hammer up a slab or open a subfloor.

Yes of course they go down, it's just a question of where.

By keeping the vertical part of plumbing out from under your toilet and bathroom in general, you get different options for designing your building.
By keeping your plumbing runs in a wall chase you can access them without a sledge or jackhammer.

At work I am often entering large utility chases, and even though the space is tight, its much better than the crawlspaces I've been in.
They are usually multistory, with expanded metal flooring on each level.
I can imagine a central utility room acting as a big walk in chase, with laundry, bathing , toilet and kitchen clustered around it, in single family house.
Add your furnace and electrical panel , land line and Internet and basically you have an above ground basement, so what's the point?
Well basements are expensive, that's the point.
What if instead of the adding the other utilities to the first floor utility room, we add stairs to a utility attic?
Only the plumbing needs to be run through the foundation, everything else can probably go upstairs.
This mimics some of the commercial buildings I'm familiar with, with most of their HVAC equipment in their penthouse instead of in a basement.