Replacing windows in an old building from 1968

Hello
we have just taken over my mother's house.
And there are old windows in it, about 35 years old (plastic, double glazed). Since they do not close properly / some have blind panes, etc., we want to replace them.
The house was built in 1968 and has about 30cm hollow blocks with plaster inside and outside.
The roof is well insulated. No insulation on the exterior facade for now because it is simply almost unaffordable at the moment. The roof has just been redone with a photovoltaic system and a new heating system (condensing boiler).
So now we have received several offers, and everyone writes something different.
What would be recommended?
I think double glazed with window ventilation (because one apartment is rented)
or
triple glazed with ventilation in the window
or double/triple glazed without window ventilation.

Price is not important for now, but we do not want mold, especially in the rental apartment.

Thanks in advance!

Mold occurs when warm air condenses on cold surfaces and there is no draft to dry it out. Since the old windows are probably not so leaky that air really passes through, I think that double or triple glazing has no influence on the risk of mold. I know that some window manufacturers say otherwise, but some don’t have even basic knowledge of physics. I can’t say anything about ventilation, but if at all only with heat recovery. The window reveal as the most critical spot can be insulated with silicate boards.

Whether double or triple glazing makes no difference regarding condensation on the wall. Both have better U-values than your 1968 hollow block wall.

- Take triple glazing with a warm edge; 6-chamber profiles are more stable than the cheap 5-chamber ones with a 68 mm installation depth.
- If exterior wall insulation is not an option, then I would recommend interior insulation with aerated concrete panels or wood fiber insulation boards, 6-8 cm, if renovations are going to take place indoors anyway.
- Otherwise, at least jamb insulation with 2 cm wood fiber to prevent condensation and mold growth there, and replace the window sills with wooden window sills inside to reduce the thermal bridge effect there as well.

I would choose the windows without destroying the window rebate; that is nonsense.
Instead, either a simple exhaust system in the bathroom with continuous ventilation at a low level (not just a loud on/off fan controlled by the light switch, but continuous operation for minimum air exchange)
or decentralized ventilation with heat recovery in the kitchen, bathroom, and living area. No alternating supply and exhaust fans but individual units, e.g., Zehnder Comfo or there is also one from Wolff.
Alternatively, when replacing windows, there are also controlled/electric fans that can be installed as frame wideners or hidden in the jamb area. However, I have no experience with these and view them somewhat critically because this then causes a continuous airflow similar to tilted windows at the jamb.