ᐅ Are there special regulations for porthole windows? Single-family house with 1.5 stories.

Dear community,

My family and I are considering building a new single-family house. According to the current plan, the house would have one and a half floors. In the bedroom on the upper floor, the knee wall height is about 1.70m (5 feet 7 inches). Please don’t laugh, but I’m someone who likes to be able to look outside on all four sides of the house. Unfortunately, with a knee wall of 1.70m (5 feet 7 inches), a roof window wouldn’t make that possible. Now I’m looking for a solution.

- Dormer -
To be honest, it’s too expensive for me.

- Roof window with fixed glazing -
That’s an option, but with shutters and so on, it’s also quite costly.

- Window slit -
According to the architect, the glass pane for the window slit would only be about 15cm (6 inches) high. That seems very small. Not really worth it, right?

Would a porthole window be an idea? Are there any special regulations for that? Could a small porthole window of about 60–70cm (24–28 inches) be installed with a knee wall height of 1.70m (5 feet 7 inches), or is that too tight? How much would a round window like that typically cost?

I’m grateful for any advice. Maybe you have other suggestions to solve my window problem?

Best regards,
Marple

Marple schrieb:
Dear community,

my family and I are considering building a new single-family house. According to the current plan, the house would have one and a half stories. In the bedroom on the upper floor, the knee wall is about 1.70 meters (5 feet 7 inches) high. Please don’t laugh, but I am someone who likes to be able to look outside on all four sides of the house. Unfortunately, with a knee wall of 1.70 meters (5 feet 7 inches), this would not be possible with just a skylight. Now I am looking for a solution.

- Dormer -
Honestly, it’s too expensive for me.

- Skylight with fixed glazing -
This is an option, but with shutters and so on, it also becomes quite costly.

- Window slit -
According to the architect, the glass pane in a window slit would only be about 15 centimeters (6 inches) high. That is really tiny. Not worth it, right?

Would a porthole be an idea? Are there specific regulations for that? Could a small porthole of about 60–70 centimeters (24–28 inches) be installed with a knee wall of 1.70 meters (5 feet 7 inches)? Or would that be too tight? How much would a round window like that cost?

Porthole(s): That would at least give you a very unique house. I usually know these round windows from gable ends or as windows at the top of stairwells. Also, the question is about the actual usefulness (meaning actually looking through) – if you are taller than 1.60 meters (5 feet 3 inches), you would always have to bend down to look through. Especially since portholes need to be placed even lower (below the ring beam).

Window slits: Whenever I see houses like that (or houses with narrow windows), I immediately think of a loophole. But of course, that is a matter of taste. Narrower windows are considered modern.

Have you thought about reducing the roof pitch and possibly having two full stories? With the current knee wall height of 1.70 meters (5 feet 7 inches), you’re not far from that. That way, you could easily accommodate your windows. This is also a matter of taste: I have always preferred rooms where I didn’t have to worry about placing furniture (i.e., full floors).

Two full stories would definitely be my preference, but unfortunately, the building regulations in our residential area do not allow it. We are all fairly tall, so we would really have to bend down to look out of the round window. But it would certainly look interesting.

Well, then maybe we’ll just skip having a window facing the garden.

Thanks and best regards,
Marple

Are there not those "fold-out" balcony windows? I’m not exactly sure what they are called.
Try googling the term "fold-out balcony" – there are also less bulky versions of these (I once saw it on TV).
I believe they are often used in sloped roof areas to allow looking out of a window and even stepping onto a small platform when opened.

@Bauexperte
Help – you probably know what I mean!

Why not use an "angled" window, for example a roof window with fixed glazing and directly below it another window of the same width, so that both are set at an angle corresponding to the roof pitch? This way, there will be a frame visible where they meet, but if a dormer is not an option, compromises have to be made. I don’t like porthole windows, and you have to stoop down for those.

Honestly, I don’t really understand the issue now.
Who is specifying that a window must be installed higher than 170cm (67 inches)?
Our kitchen counter ends at around 150cm (59 inches), which directs the view downward toward the garden bed rather than toward the neighbor’s house. Our bathroom window isn’t any higher either… since you don’t stand directly in front of it but look through it from inside the room, you can still see plenty outside.
By now, there are so many model and show homes that install windows at various heights, widths, and sill heights—you can get plenty of inspiration from those.
Besides that, when it comes to self-builders, I just assume they have at least skimmed through the first 10 out of a thousand websites about architecture, modern design, etc., and have therefore come across some unconventional ideas—like a porthole window, which is also part of the creative process. That said, it’s not really related to the problem you mentioned because such windows also need to be set lower or smaller to fit into the knee wall.

Regards,
Yvonne