ᐅ How is the knee wall height calculated?

Created on: 1 Jul 2016 18:25
C
Chrisbo
Hello,

can someone explain how the knee wall height is correctly calculated?
I currently have quotes from two builders, and they calculate it differently.

Data

Knee wall height 80cm (31.5 inches)
Roof pitch 38°
Wall thickness 36cm (14 inches)

1. 80 cm (31.5 inches) knee wall height on the outside corresponds to about 100 cm (39 inches) on the inside
2. 80 cm (31.5 inches) knee wall height on the outside corresponds to about 65 cm (26 inches) on the inside

Excerpt from the development plan

The knee wall height of the attic must not exceed 80 cm (31.5 inches). The knee wall height is defined as the distance between the top edge of the attic floor and the intersection line of the outer surface of the wall with the underside of the roof covering.

I am not asking for an exact value, but which builder is wrong?!

Best regards

Chris
C
Chrisbo
2 Jul 2016 08:10
Thank you for the many details.

The city of Nauen refers to the development plan.

Perhaps a meeting at the local building authority could be an option?

Best regards

Chris
B
Bauexperte
2 Jul 2016 08:58
Hello Chris,
Chrisbo schrieb:

Knee wall 80cm
Roof pitch 38°
Wall thickness 36cm

1. 80 cm knee wall outside is about 100 cm inside
2. 80 cm knee wall outside is about 65 cm inside

Excerpt from development plan

The knee wall height
of the attic must not exceed 80 cm. The knee wall height is defined as the distance between the top edge of the attic floor and the intersection line of the exterior wall surface with the lower edge of the roof covering.
It "could" be that both calculations are correct but use different approaches. One might measure from the rough floor to the roof covering intersection, the other possibly from the finished floor (FF) to the clad roof slope = finished dimension.
Chrisbo schrieb:

The city of Nauen refers to the development plan..
That is within their rights; with the development plan, the city can, among other things, set specific height requirements.
Chrisbo schrieb:

Would a meeting at the local building authority be an option?
Of course, you can do that. The city of Nauen likely offers building consultation services for homeowners.

On the other hand—why should you do that, aside from an initial introduction to house building in Nauen? The temporary building partner you choose is responsible for compliance with the development plan. If an architectural firm is involved, it is among the planner’s duties to adhere to the development plan’s requirements.

Regards, Bauexperte