This van is self-contained, with 2 tanks for fresh and grey water, with a chemical toilet, a solar system with 230V electricity, a fridge, a cooker, and much other useful stuff inside! It’s proven by 6 months of living on the beach. Thus I definitely know what works, what could be maybe done better, or what I will completely skip or do in a different way for the next time and I can advise you what to beware of.
Even parking your future 5 star hotel on the wheels is not easy; finding a good spot could be a science! We can talk about all the things connected with the building and living in a van. Connecting your solar panel? Putting the water inside? It’s just up to you guys!