Street noise in attic apartment / penthouse

Hello everyone,
thank you very much for your numerous responses! I take from this that the perception of noise varies greatly and accordingly whether one is bothered by it or not. We should also not overestimate the effect of the future whisper surface.
A few days ago, the four of us stood at the future location, of course directly by the street and not 12 meters high. And the noise of the cars was so loud that we could hardly speak to each other. And that made us somewhat doubt.
I understand that sound propagates in a straight line. Around us there are only buildings that are significantly lower than our future one. Therefore, the reflected sound should also be limited. Furthermore, our terrace will be really large and we don’t have to sit right at the railing. All arguments that should reduce the street noise to a reasonable level. “Should”. How it really will be is hard to say. This will be a really difficult decision for us. Because the floor plan and the architectural firm would be great.

That will be a really difficult decision for us. Because the floor plan and the architectural firm would be great.

I can sympathize with that. It's really difficult. You can let us share your excitement and post the floor plan.

Regarding the "sound cone": It may be that a lot of the volume flows upward. However, I can report from first hand that the noises carried through the mass - i.e., the street - into and onto the house are the bigger problem. Nothing is decoupled there, and even an electric car causes perceptible noise. On the other hand, this problem will lose significant relevance on the 3rd floor because primarily the ground floor and mezzanine are affected.

Buy yourself a data logger and measure for a few days on the terrace, if possible. Is the shell already built? Large plants on the terrace can also reduce the noise.

You can hardly (if at all) infer the noise level upstairs from street level. The paths of sound waves are quite special. Due to reflection, it can be quieter or louder, and this is not apparent just by looking or from the street. The only thing left is to sit on the terrace on a weekday and a weekend day ...

If the terrace really offers enough space, one can also make things more pleasant with appropriate planting. Are the bedrooms also facing the street? Or are they on the side away from the street? That would be more important to me personally if you sleep with the window open.

The noise on the terrace will weigh less due to the location and the fact that you are rather active there and busy processing other impressions. And as already mentioned, there are other ways to reduce the sound if it really gets too loud.

If you like the apartment and it is otherwise attractive to you, I would go for it.