> Couldn't it be held in holding tanks and then allowed to flow out during off hours?
I don't think it's a timing issue. The issue is that the fresh and wastewater plumbing simply doesn't exist in the places you'd expect in housing, so there can be a significant cost to adding it, beginning with just figuring out where you can run it through the existing spaces.
A holding tank and whatever pipes then are used to empty it are still plumbing, and even more complex than regular plumbing, unless you are suggesting that people would haul their own waste out periodically.
Also recall that wastewater pipes need to be at least slightly angled so that they drain properly using gravity, further constraining their potential paths. This can be quite difficult to design even when remodeling a regular house.
Not sure I agree. The other comments seem to say that office buildings are designed for a certain amount of water capacity. So even if you supplement (?) and add nodes (?) there's still a bottleneck of capacity. So, if water collected in tanks on each floor then it can be dripped out (so to speak) to not exceed capacity.
Even if total wastewater disposable capacity was the issue (which would be surprising considering the highly correlated toilet use in many office buildings after breakfast and lunch), the more fundamental problem is that the drain pipes are not distributed in a way conducive to residential use, or put another way, most people don't want communal bathrooms.
Drains need to be sloped to the riser pipe. And in nearly all offices thats concentrated in the middle, which implies a huge slope for drains coming from several dozen feet away.
I don't think it's a timing issue. The issue is that the fresh and wastewater plumbing simply doesn't exist in the places you'd expect in housing, so there can be a significant cost to adding it, beginning with just figuring out where you can run it through the existing spaces.
A holding tank and whatever pipes then are used to empty it are still plumbing, and even more complex than regular plumbing, unless you are suggesting that people would haul their own waste out periodically.
Also recall that wastewater pipes need to be at least slightly angled so that they drain properly using gravity, further constraining their potential paths. This can be quite difficult to design even when remodeling a regular house.