ᐅ Bathroom accessible from two sides – What type of locking system?

In our regular bathroom, we also have two doors. You simply lock and unlock both. It takes just one second longer and is not worth mentioning. I wouldn’t want a technical solution for that.

I also wanted to suggest the pragmatism of @Bookstar. How much money are you willing to invest to reduce the risk that a careless person might be embarrassed by being disturbed while using the toilet?

And then you invest thousands, only to be startled from the pool lounger by a loud scream from someone caught in the situation described above, shaking the entire neighborhood. No technology could prevent the forgetting of locking the perfect secondary door system.

I like the idea of having a bathroom accessible from the outside. Especially when children use the pool, they often need to go to the toilet and aren’t very careful about drying off. I would also install a patio door that you can simply open when it’s pool time. It will happen that some people or children forget to unlock the interior door again. To avoid this, you could also plan a small lockable toilet room within the bathroom. Something like a T-shaped or L-shaped layout with a door in front. Then you only lock the toilet when needed.

I don’t think the idea of having direct access from the ground floor bathroom to the terrace is crazy, as was suggested earlier.
However, I believe you are overcomplicating things. Think about separate poolside bathrooms that are also used for changing. In that respect, I agree with @kbt09 on the optimal design:
Plan a terrace door. On a pool day, you enter through the bathroom to change and use this terrace door. If you need to use the toilet or shower, you go back inside through the same door. After a full day at the pool, you close the door from the inside. That being said, I would also carefully plan the bathroom and the ground floor layout—the sketch looks a bit vague to me.
Since you probably aren’t a six-person household that feels awkward about toilet visits, there is no need for a locking system. You can simply make arrangements among yourselves.

Thank goodness at least two people don’t find the idea so unacceptable 🙂... If it were to come to that, I would probably manually lock both doors. It’s a pity there isn’t an option for that.

I also think the idea is good, but I wouldn’t invest in technology to prevent both doors from being opened. When the pool is being used outside, the interior access is simply locked. When nothing is happening outside, the patio door is closed. Quite simple.