summer thermal protection - reduction of windows?

Thank you for your answers. helps little.

You asked about an air conditioner, I answered. If you do not want the question to be answered, then please do not ask it. Otherwise, the further answers should very well help, because if your project is so tight that a few thousand euros more are not feasible, then you should cancel it.

Hello,
I am not surprised that the architect did not plan any thermal insulation. For some reason, it seems that during their studies, they are taught that

[*] any exterior thermal insulation is ugly and therefore devil’s work
[*] all physics books are nonsense and the same thermal insulation can also be achieved by thin curtains inside the room
[*] and generally blackout curtains etc. are complete nonsense because everyone likes to sleep in a bright room and it’s not a problem at all that it is already bright at 4 a.m. in summer...

So far, I have not met a single architect for whom at least two of the three points above did not apply.

Regarding your problem: be thankful to your energy consultant and buy him a crate of beer directly. He saved you from a major construction mistake. A room with 18 sqm of west-facing windows is likely to be practically uninhabitable for half the year. Unless you enjoy temperatures over 30 degrees in your living room.

You can forget about cooling via controlled residential ventilation; the volume flows are simply too low for that.
Cooling via underfloor heating might bring 1-2 degrees at most.
As an air conditioner, you will need a lot of cooling capacity. Roughly 1 kW per sqm is delivered by the sun. Even if you subtract 50% because of angled incidence and coated glass, you end up with about 9 kW. That is a very large wood stove running at full power!!

You only have two realistic options:

[*] Exterior shading
[*] Much (!!!) smaller windows.

Best regards,

Andreas

Building without external shading is nonsense nowadays. Figure out how to get roller shutters or external blinds on the house. You should still prepare the air conditioning or have it installed right away. It will get warm.

Be glad that the energy consultant pointed this out to you. Otherwise, you would be here again next summer asking about radio-solar-DIY-shutters. Now you still have the chance to do it right from the start.

We have alternative sun protection glazing in the office at work. You feel like it's always bad weather there, even when the sun is shining brightly...

If you don't have money for roller shutters, a large roof overhang might really be the best option. Or an inexpensive canopy in front of the large windows or an awning. It helps as small or too few windows. Because even if no direct sunlight comes in, window openings light up the room in a completely different way than lamps could. I wouldn't want to miss that.

Be glad that the energy consultant pointed this out to you. Otherwise, you would be here again next summer asking about radio-solar-DIY-shutters. Now you still have the opportunity to do it right from the start.

I can only confirm this from experience.