ᐅ Attic size with a knee wall height of 1.50 meters

Hello, we are currently planning our house and have a floor area of 147 sqm (8.20 x 12.01 m). We initially wanted to build two full stories but have now decided on a 1 1/2-story design with a knee wall height of 1.50 m (4 ft 11 in) due to cost considerations.
We want to use a gable roof with a 45-degree pitch.
I wanted to find out what the usable floor space would be in this case.
On Monday, we visited a smaller model home that had a knee wall height of only 1 meter (3 ft 3 in), and the roof pitch seemed shallower to me. When I was upstairs in the attic space, I was quite surprised that I could only stand upright in the middle, and there was hardly any usable space elsewhere.

Take graph paper and draw to scale. This way, you can accurately measure exactly how much space you have and where.

Marc1 schrieb:
That only had a knee wall height of 1 meter (3 feet 3 inches)

The higher the knee wall, the taller the attic space.

The flatter the roof, the lower the attic space.

The width of the house under the ridge also has a significant impact.

Of course, the roof structure, the construction of the intermediate ceiling, and the room height on the upper floor also matter.

Is your roof oriented across the 8.5 meters (28 feet) side or the 12 meters (39 feet) side?

RobsonMKK schrieb:
Take some graph paper and draw to scale. This way, you can accurately measure how much space you have and where.

I was just about to say the same. Especially because you’ll notice yourself that some information is still missing in the text.

RobsonMKK schrieb:
Take some graph paper and draw to scale. Then you can exactly measure where you have how much space.

I was just about to say the same.
At 45 degrees, you can very easily use simple graph paper and halve a square diagonally from corner to corner.

36, 33, and 26 degrees also work well with a grid pattern:

36 = 4 squares to the right, 3 squares up
33 = 3 squares to the right, 2 squares up
26 = 2 squares to the right, 1 square up