Water
We need water - to drink for food prep and possibly other things. How much should we carry?
Using backpacking as a start we figured about 3/4 gal per person per day for drinking and 1/4 gallon for odd prep and cleaning. That is 2 gal per day for the two of us.
As for other things such as showers or toilets? We decided that those things were not going to part of van. More on that below.
If we use a 3 day minimum off the grid stay, we would need 6 gallons. The question then became would we install some type tank, pump and sink or continue to do what we do camping. Having a faucet and sink would be nice but it then requires a grey water tank. That was enough for us to choose our regular camping set up with a jug and a spigot.
A 5 gallon containers, 2 gallon jug and 1 gallon in water bottles will give us about 4 days of water.
Other plumbing
Having a toilet and a shower do sound appealing. What did not sound appealing was having a black water tank.
So showers would be something that happened in camp sites that had showers. And there are black bag shower kits that warm water in the sun and be used to rinse off if we really feel we need it.
The toilet though was hard to completely pass up. In the end we opted for a portable unit that we put a plastic bag and kitty litter in.
One other that we considered for its compact stored size is the Blackpine Turbo Toilet.
Next - where to store the bikes.