Nuclear reactor inside and t3 o2

[Violent]

Why can't you build Nuclear reactors and T3 O2 inside?

[nul]

I think the reactor is simply too big. It doesn't give a floor error like some of the things that are mandatory to put outside. But it does clip into ceilings.
T3 O2 seems arbitrary yeah. They gave it outdoor leggies.

I kinda wish you could just put anything indoor or outdoor so long as it makes sense (like not putting a water collector, wind turbine, solar panel, etc indoors)

[Nefai]

I am in the opposite boat, lol.

Why can't you build T1, T2, T3 Heaters, or T1, T2 Vegetubes OUTSIDE? :)

[Pesky]

Violent:

Because the emit hot gasses as they operate and the ventilation system of your living compartments can't cope.

Nefal:

Because they don't work in the cold or in the low pressure. To operate they need roughly the same temperature and pressure you like.