ᐅ Uncertainty Regarding Knee Walls as a Building Regulation in the Development Plan

Hello everyone,

The residential area where we would like to build is now approaching the final stages (public review, infrastructure planning, and allocation all this year). This is a good reason for me to take a closer look at the development plan.

The building regulations include the following provisions:

My questions regarding this:

For WA1, the situation is quite clear to me; it is possible (but not mandatory) to build classic urban villas with two full floors. For the WA2 area, I would say that typical 1.5-story single-family homes can be expected, meaning a normal ground floor, a first floor with sloping ceilings, and then an attic. The WA4 area is somewhat unclear to me, or perhaps I do not fully understand one of the terms used: Here, the eave height is the same as in WA2, but the maximum allowed ridge height is 2 m lower (9 vs. 11 m (30 ft vs. 36 ft)). Accordingly, the roof slope is probably shallower here, about 30 to 42° compared to 42 to 48° in WA2. Does this imply that it would be more reasonable to build “only” bungalows in this area?

My point of confusion: the specification of the knee wall height.

As far as I have researched, the knee wall (Drempel) is a kind of short wall built under the roof, something like this:

[IMG width="387px"]https://www.profiheimwerker.info/wp-content/uploads/2019/03/dg-verkleidung-drempel6-e1553690350536.jpg[/IMG]

By contrast, there is also the “knee wall” or “knee wall wall” (Kniestock), which (as I understand it) actually adds usable space. In this case, the roof is not placed directly on the floor slab of the upper story but on the knee wall, which corresponds to a wall raised above the floor slab, like this:



If my understanding here is correct, I really don’t understand why the knee wall height (Drempel) should be limited in a development plan? After all, how I use the space under the roof is my decision, right? If I install a drywall partition inside (which is not visible from the outside but more like a piece of furniture), for example, to use the cavity behind the knee wall as storage space, that should not concern the building authority, right?

Addendum: Here is the official description of the knee wall height:

The maximum allowed knee wall height is 80 cm (31 inches). It is to be measured on the exterior wall between the upper edge of the attic floor and the underside of the roof rafters. (§84 para. 3 no. 1 Lower Saxony Building Code)

I hope I was able to explain my confusion clearly enough and look forward to your feedback.

Best regards

In your case: Drempel = knee wall. You can build as many non-structural walls inside as you want, but you cannot raise the roof height.

Hello,

okay, so this means that the 4 or 7 meters (13 or 23 feet) given here as eave height already include the knee wall (referred to here as Drempel), correct?

Then to my other question:

Is it even reasonable or possible to build a single-family house with 1.5 stories in WA4 ("living area 4") with a maximum ridge height of 9 meters (30 feet), or do you see no issue with that? Would this make no difference for the first upper floor but only result in a lower attic space or the attic being completely lost?

Best regards

Bitschieber schrieb:

my understanding

... aligns with the terminology used here in the forum. In everyday life, these terms are mostly used interchangeably (see Wikipedia).

Bitschieber schrieb:

Is it even reasonably possible to build a single-family house with 1.5 stories in WA4?

Yes.

Bitschieber schrieb:

Do you see no problem with that?

Yes, I see no problem.

Bitschieber schrieb:

Would it make no difference for the first floor at all?

That depends on the size of the house. For a house with a 42° pitched roof and a 10m (33 feet) wide gable wall, it makes no difference.

I’m glad that you understand the difference between knee wall and dwarf wall. Your zoning plan providers tend to follow common usage, which often mixes up these terms. And yes, the knee wall is included in the eave height, and I appreciate your agreement that it therefore does not require separate regulation. Finally, I’m not the “only one” who gets this, but unfortunately, neither of us is responsible for creating zoning plans ;-)

I see the lower ridge height here as directly corresponding to the shallower roof pitch—whether the chicken or the egg came first, we don’t need to figure that out. A house can certainly be built like this, and it does not have to be a bungalow.

I find it much more interesting personally why WA1 and WA3 mention “4 or 7” meters (13 or 23 feet) of eave height. Without explanation, Krause (A-K) would apply one value and Schulze (L-Z) the other *LOL*, or are these “valley” and “ridge” eave heights for a slope? In that case, it should, in my opinion, say “respectively.”

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11ant schrieb:

I find it much more interesting personally to ask why in WA1 and WA3 the eave height is stated as "4 or 7" meters (13 or 23 feet).

I wasn’t detailed enough there. Here, it is allowed but not required to build two stories.