Fireplace, inside or outside?

Thanks for your answers! Let's see what the architect conjures up from the floor plan and what the budget will still allow! This is actually one of the things on the chopping list if the budget gets out of hand! Unfortunately...

We have both variants in the house, the one for the boys' two wood stoves is made of stainless steel, internal and internally lined, the one for our masonry stove is made of stainless steel external. Fresh air intake from outside also works with stainless steel, it does not have to be built with masonry. Ultimately, it is a matter of style. The externally located one is on the covered terrace (top picture) and goes through the flat roof of the middle building section and then through the roof overhang. Thus, from a distance, it does not look externally located at all (older picture with scaffolding - the left one is externally located.

Ours cost 4000 internally. You can't just use any DIY store heater anymore. With [Kontrollierte-Wohnraumlüftung] you have to reckon that you need a pressure switch. Also not cheap.

Ours cost 4000 inside. You can no longer use just any hardware store stove. With controlled residential ventilation, you have to calculate that you need a pressure monitor. Also not cheap.

4000€ for everything? Fireplace, stove,...

Ours cost 4000 internally. You can't just use any hardware store stove anymore. With controlled residential ventilation, you have to factor in that you need a pressure switch. Also not cheap.

10 the chimney from Plewa including supply air
2 the stove
1 the installation
2.5 the pressure switch.

The surcharge for our Gu was 4500 euros, the pressure monitor is extra, the neighbor installed one for 800 euros. I will probably do the same if I ever need it.

A kit costs around 600-1200€ on eBay. Visually, I don't find them that bad at all. With installation by a company, you are probably at 2000 euros, so you save a lot of money.