ᐅ I need help with the knee wall / eaves / roof pitch.

Created on: 6 Apr 2011 10:13
L
Langis
L
Langis
6 Apr 2011 10:13
Good morning.

I would like to ask for advice from a specialist.

The following specifications are given in the development plan for our plot.

Roof pitch: 35-45°
Eaves height: 3.5-4.0 m (11.5-13.1 ft)
Ridge height: 8.5-10.5 m (27.9-34.4 ft)
Maximum allowed number of full stories: Max I
Permitted building type: detached
Allowed roof types: gable roof
Site coverage ratio: 0.4
Floor area ratio: 0.6

Now I would like to know if it is generally possible, using the maximum values such as an eaves height of 4 m (13.1 ft), to build a single-family house with a ground floor area of approximately 140 m² (1,507 ft²) and a knee wall height of 1 m (3.3 ft) in the attic on this plot? (If you design using the maximum eaves and ridge heights, the knee wall should automatically increase in height, or am I mistaken?) We want to have a relatively high knee wall so that the attic can be used comfortably for movement later on and possibly allow the addition of a room.

And the issue with the full story should not be a problem in our example, right? Since the ground floor is a full story anyway, and the first floor is located under the roof, it counts as an attic and therefore not as a full story.

I would appreciate a professional clarification.

Thank you in advance.
L
Langis
6 Apr 2011 11:04
Oh, and one more thing I need to add: a dormer is included in the design of the first floor.
E
E.Curb
6 Apr 2011 11:37
Hello,
Langis schrieb:

And the issue with a full storey shouldn’t really be a problem in our example, right? Since the ground floor is already a full storey and the first floor is located under the roof, it counts as an attic storey and is therefore not a full storey.

The definition of a full storey is regulated by the building code of the respective state. In Schleswig-Holstein, for example, a storey is considered full if it has a height of at least 2.30 m (7.5 ft) over at least three quarters of its floor area—regardless of whether it is under the roof or not.

In many other states, the requirement is only two thirds of the floor area or a height of 2.20 m (7.2 ft). So you need to check the building code of your state. This is usually easy to find online.

Whether your building counts as one or two storeys is best determined by drawing a section and adjusting the knee wall heights until you reach the maximum height at which your attic storey clearly is not a full storey.

Best regards
L
Langis
6 Apr 2011 11:55
Ok. In our case, it would be for the state of NRW.

Hmm... In that case, the only option is probably to submit a preliminary building permit application to the building authority and present this request there; maybe they will be open to discussion.