Boiler size in circus wagon (with plans)

Hello everyone

As a temporary residence (during the house renovation) I am currently building a caravan that stylistically resembles a circus wagon. It includes a small shower and a mini kitchen. (Plans as PDF are attached)

My original idea to generate hot water with an instantaneous water heater turned out to be unfeasible (too high power consumption). So only a boiler remains. It should not be larger than necessary since space is limited. Effectively, I am even considering acquiring a horizontal model and installing it below the floor, basically in the chassis (and surrounding it with an insulated wall).

The question now is: How big does the unit have to be? It must be sufficient for 2 people to shower within an hour (assuming that the showering process is not prolonged longer than necessary). Many numbers circulate on the internet about water consumption during showers, or what the minimum size of a boiler in a small two-person household should be. I think it should be at least 100 liters.

Does anyone have experience with this? Any recommendations?

Thanks and regards

Michael

Have you also looked around in the specialist trade area for caravans? Just take a look under Truma. That is a renowned manufacturer for [Thermen]. Costs start from €200 upwards.

How do you heat the caravan? Where is the wardrobe? How high are the planned costs? How do you want to seal the shower cleanly?
I am a camper and looking forward to your explanation. :)

How do you heat the vehicle? Where is the wardrobe? What are the planned costs? How do you want to seal the shower cleanly?
I am a camper and looking forward to your explanation. :)

We heat the vehicle electrically. The wardrobe is where a wood stove is currently shown. I wanted to fit the shower cabin with Phermacell. However, I was recommended the Wedi board from various sources. Costs... we'll see then. It won't be cheap.

The question of how big the boiler needs to be is still open. Does anyone have experience?

Michael

I just watched a report on TV about Tiny Houses and briefly skimmed the website: I thought there were also construction plans etc. posted there. Are there no information there regarding your question?

In my opinion, the boiler is sufficient. A water heater is unnecessary because the boiler works like an instantaneous water heater.

Why don't you buy a caravan?

From various sides, however, the Wedi board was recommended to me. Costs... we will see then. It won't be cheap.

Since you mention the topic (a bit off-topic here):
The Wedi boards are certainly much better in terms of thermal insulation, but also significantly more expensive than Fermacell boards. I used Wedi boards during the bathroom renovation, for example also for the window reveal, where the old plaster came down when removing the tiles. However, the Wedi boards are not as smooth as Fermacell, but require plaster or at least a full-surface filling if you do not tile over them anyway. On the other hand, they are excellent because they can be glued on directly.