Expansion of the attic in a hip roof as a basement replacement

Hello,
we are currently planning our dream house with approximately 190m², and the following situation is occupying us at the moment:

Of course, also for reasons of total cost, there is consideration not to build a basement (the plot is flat and 1170m² in size). From the planning side, the suggestion was made to use the attic for storage but also usable space (office, hobby, fitness). We like the idea more and more, also because the view is significantly better than in the basement;)

The hip roof would then be executed with 30° plus parapet, and a normal staircase would lead up to the attic. Recently, the idea even came up to locate the building services in the attic, which according to feedback has also already been done. But I am still very skeptical about that; otherwise, it would have to be accommodated in an ancillary room next to the garage.

I now hope for numerous assessments on the following questions:

• Has anyone completely converted an attic in a similar way (hip roof, size), and what are the experiences with it?
• How do you generally like the idea (even without practical experience), and do you consider the approach sensible or what should be taken into account?
• What speaks against putting the building services in the attic?

Here is a floor plan of the attic (only the attic because that is currently the primary concern):


Thank you very much!

The idea appeals to us more and more, also because the view is much better than in the basement;)

Well, there is no view with skylights. You look towards the sky… The problem with a hipped roof is that there are no approved and official living spaces because the second emergency exit is missing. If you possibly want to sell someday, you need to either have a "level for children" or not mention it at all. It then becomes a house with a basement replacement room under the roof. Basically, it always makes sense to use what is already there. However, a gable roof offers more potential with the gables, which is why I also recommend a gable roof. A hip roof can really press down from above. And due to the lack of an escape route, it also has a claustrophobic factor.

Well, there is no view with skylights. You look towards the sky...

From Velux there is the so-called "Cabrio" double casement window, a cool system that should also work with a 30° pitch:

The problem with hip roofs is that there are no approved and official living rooms because the second escape route is missing

Here a corresponding double casement window that is sufficiently large and whose sill height in most state building codes must not exceed 120 cm is recommended. The planner should know this. What could be more disturbing are the roof trusses, which - if realized this way - take up quite a lot of space.

I would also recommend the gable roof with studio trusses as a cellar replacement. Great view at the gables, much more usable space, and cheaper. Better, because higher rooms possible, loft bed under the roof trusses e.g.

Thank you very much for the previous answers and inputs: - the thing with the official lounge is definitely good to know, I don’t think it feels cramped (at least to us) - the double casement window looks very interesting, thank you! - we definitely want to avoid a gable roof, we simply don’t find it fitting to the current plan and we don’t really like it either

Velux offers the so-called "Cabrio" double casement window, a cool system,

Yes, at a bargain price ;) If you then put two next to each other and then on two areas in the attic, including installation, that has its demanding value. But it really is stylish!

What speaks against the building services in the attic?

Hm, not exactly sure, but the connections would probably have to go into the ground floor anyway? Then you’d have to know if the attic has a wooden floor, i.e., between the upper floor and the attic regarding load-bearing capacity.
At least you can nicely realize a large storage room, and have realized it nicely.