Bavarian Building Code - Are dormers in flat roofs not allowed?

  • Erstellt am 2023-11-03 20:01:13

Bienenwabe

2023-11-03 20:01:13
  • #1
Hello, we want to build a dormer on a roof with a 25° pitch. An architect told me that this is not allowed by the Bavarian Building Code because the roof is too flat; it must be at least 35°. When I, as a layperson, read through the regulation, I don’t find anything about this. Does anyone know about this? Thanks for tips.
 

ypg

2023-11-03 22:08:16
  • #2
I think I understand that it is regulated in the BPlänen.

To ask differently: what do you want to achieve with the dormer? Either you have a low wall plate height resulting in a flat roof, where the dormer will not be subordinate, or you have a high knee wall so that you cannot use the dormer in the area of standing height at all. I can believe that one might come up with the idea in the first case. But structurally it will have to be made far too long. I don't even want to imagine how that looks.
 

11ant

2023-11-04 14:14:52
  • #3

Basically, any set square can explain this to you: the flatter the roof pitch, the longer the dormer must be to achieve the same height gain. A window 1 m high results in a dormer 2.14 m long (although you probably mean a "dormer" aka cross-gable). In addition, dormers/cross-gables usually have a shed roof with a pitch not far from 20°, which would make the dormer or cross-gable infinitely long and require an enormous house depth to reach before the ridge.

I think you should at least discuss a concrete building form, otherwise you will never get anywhere.

By the way, I believe we only know the remark from your development plan

as the attitude of the municipality, whose vote the district office usually follows.


I can only agree with that.
 

Bienenwabe

2023-11-04 15:45:48
  • #4
Thank you for your comments. What I want to achieve with this is to create space for a desk where it is needed and where there is none today. The appearance and such don't really matter to me. The carpenter I trust said structurally it's possible to add a "Gaube," he has seen the plans. Whether dormer or "Gaube," he should decide. There is no development plan in the area, there are all kinds of different houses. As I said, I wonder if the Bavarian building code contains any regulations regarding this.
 

11ant

2023-11-04 16:02:14
  • #5
Oh, have you built in the meantime (and planned tightly in terms of standing height)? – show us what would need to be repaired. Whether the roof structure is a dormer or a cross-gable depends on its location: if placed on a (lower) purlin or the knee wall, it is a dormer; if placed on the outer wall or its knee wall, it is a cross-gable. If there is no development plan, I do not see any rejection of the dormer derivable from the integration requirement and would rather not expect the building authority to reject the conversion or even to check for conformity with the state building code.
 

Bienenwabe

2023-11-05 09:25:33
  • #6
It is not a construction wound, rather an optimization after purchase. We bought a house and since the renovation was cheaper than planned, we are considering moving the study from the basement to the attic. Unfortunately, a standing desk does not fit there today.

It is a tent roof with a 1m knee wall and we are now considering expanding a bit to the east and west. Appearance, as said, is secondary.
 

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