Before starting a conversion and if the size of the van allows it is necessary to think about whether or not we want to have a bathroom, since it will take up a lot of space in the interior and will add a lot more work because it is necessary to do the plumbing, to have a deposit of dirty water, plus it will almost certainly imply some kind of legalization / booklet change to avoid problems with authority.
If we think having a bathroom is indispensable?
No, for those who want to make a transformation to travel a few weeks / days from time to time, especially in summer and never getting too far from water, having a bathroom is not necessary, before we had the van finnished we traveled 2 weeks through Portugal and we did not use the bathroom or toilet once.
We traveled in the interior, stopping at many river beaches, and in almost all of them it is possible to find a shower / toilet / bathhouse.
On the other hand we also have an outdoor shower (use natural soap to not harm the environment) and we can always take a shower.