ᐅ Single-family home with 160 m² – zoning plan and living space calculation
Created on: 26 Oct 2020 12:53
R
RevilooHello everyone,
We are looking at a building plot where the development plan raises a few questions for me.
We would like to build approximately 150–160 m² (1,615–1,722 sq ft) in size.
The desired plot is almost exactly 500 m (1,640 ft). The “building volume” should be about 9 x 12 meters (30 x 39 feet).
The development plan specifies the following:
Number of full stories: I
Site coverage ratio: 0.4
Floor area ratio: 0.4
Eaves height: 4.5 m (15 ft)
Ridge height: 7.0 m (23 ft)
Roof type: GD
Roof pitch: 15–45°
State: NRW
What I don’t fully understand is:
The floor area ratio means that theoretically we are allowed 200 m² (2,153 sq ft) of living space.
Do I understand correctly that because of the restriction “Number of full stories = 1,” the living space on the upper floor can be a maximum of 75% of the ground floor? For simpler calculation, for example, 100 m² (1,076 sq ft) on the ground floor and 75 m² (807 sq ft) upstairs?
How important is the “clear height” here? How exactly are the 75% on the upper floor calculated in relation to the sloped ceilings?
I understand that for knee walls between 1.0 and 2.0 m (3 and 6.5 ft), only 50% of the area counts as living space (please correct me if I’m wrong). What exactly does the “clear height” of 2.30 m (7.5 ft) refer to regarding the living area calculation?
How precisely can we plan here?
One idea would be to make the rooms on the upper floor more “usable” by adding dormer windows in some way.
If I understand correctly, the development plan also allows some flexibility here.
Subordinate structures (such as projections, bay windows, cross gables) in the designated WA 2 and WA 3 zones may exceed the maximum eaves height on up to two-thirds of the building length (see also provisions C.13 Roof structures / roof cutouts).
What would you recommend or how would you approach building here?
From the floor plan point of view, we find the house “Auro” by “Kern-Haus” interesting. However, it says this would not count as one full story in NRW—I don’t understand why?
Three children’s rooms and a home office are important.
Maybe you can shed some light on this.
Unfortunately, I haven’t been able to find any clear information here in the forum yet.
Many thanks and best regards,
Reviloo
We are looking at a building plot where the development plan raises a few questions for me.
We would like to build approximately 150–160 m² (1,615–1,722 sq ft) in size.
The desired plot is almost exactly 500 m (1,640 ft). The “building volume” should be about 9 x 12 meters (30 x 39 feet).
The development plan specifies the following:
Number of full stories: I
Site coverage ratio: 0.4
Floor area ratio: 0.4
Eaves height: 4.5 m (15 ft)
Ridge height: 7.0 m (23 ft)
Roof type: GD
Roof pitch: 15–45°
State: NRW
What I don’t fully understand is:
The floor area ratio means that theoretically we are allowed 200 m² (2,153 sq ft) of living space.
Do I understand correctly that because of the restriction “Number of full stories = 1,” the living space on the upper floor can be a maximum of 75% of the ground floor? For simpler calculation, for example, 100 m² (1,076 sq ft) on the ground floor and 75 m² (807 sq ft) upstairs?
How important is the “clear height” here? How exactly are the 75% on the upper floor calculated in relation to the sloped ceilings?
I understand that for knee walls between 1.0 and 2.0 m (3 and 6.5 ft), only 50% of the area counts as living space (please correct me if I’m wrong). What exactly does the “clear height” of 2.30 m (7.5 ft) refer to regarding the living area calculation?
How precisely can we plan here?
One idea would be to make the rooms on the upper floor more “usable” by adding dormer windows in some way.
If I understand correctly, the development plan also allows some flexibility here.
Subordinate structures (such as projections, bay windows, cross gables) in the designated WA 2 and WA 3 zones may exceed the maximum eaves height on up to two-thirds of the building length (see also provisions C.13 Roof structures / roof cutouts).
What would you recommend or how would you approach building here?
From the floor plan point of view, we find the house “Auro” by “Kern-Haus” interesting. However, it says this would not count as one full story in NRW—I don’t understand why?
Three children’s rooms and a home office are important.
Maybe you can shed some light on this.
Unfortunately, I haven’t been able to find any clear information here in the forum yet.
Many thanks and best regards,
Reviloo
I’m not an expert, but I don’t understand why the Auro 2 has two full floors. A 12m x 9m footprint equals 108sqm (1,163 sq ft) of ground area. The upper floor is therefore allowed a maximum of 81sqm (872 sq ft) with a clear height of 2.3m (7.5 ft). The total living area is actually well below that at 70sqm (753 sq ft). This confuses me as well.
Reviloo schrieb:
For knee wall heights between 1.0 and 2.0 meters, 50% of the area is counted towards the living space (please correct me if I misunderstood). What exactly does the "clear height," which must be 2.30 meters, mean regarding the living space calculation? Any space below one meter in height is completely excluded from the calculation, and between one and two meters, the area counts as 50%. Whether there are actual knee walls, dwarf walls, or nothing at these virtual height lines doesn’t matter. Clear height refers to how tall a person can be standing on the finished floor without hitting their head on the ceiling. The 2.30 m (7 ft 7 in) height is not relevant for the living space calculation itself but is important for determining full stories (full floors) and their respective area calculations. This means that all areas under 2.30 m (7 ft 7 in) are not counted, while areas above are counted fully.
Since the areas mentioned on the website for the Auro (70 sqm (753 sq ft) attic versus 87 sqm (936 sq ft) ground floor) are based on the living space calculation (i.e., with the 2.0-meter relevance), not the full story-relevant 2.3-meter areas, I assume the Auro meets the single-story criteria, and the statement you mentioned is based on the incorrect assumption that the 70:87 ratio already shows the relevant areas for comparison (which would indeed be over 75%). However, the Auro has a 75 cm (30 inch) knee wall and apparently complies with the one-third limit on cross gables. The builder operates nationwide, including in federal states with a 66.66% full-story limit, so they are certainly familiar with this issue. Therefore, I assume it should be possible not only in NRW but also in the 75% states, possibly with slightly higher knee walls.
With the workspace cross gable, there might be potential for savings, while the dressing room cross gable seems indispensable because of the stair headroom. Please introduce yourself here with the completed questionnaire from the floor plan category header, so we can discuss alternatives more concretely. In the version of the Auro presented on the website, with a 75 cm (30 inch) knee wall, I see it as feasible until proven otherwise. Therefore, the statement "Number of full floors: 2 in all states except Saarland" confuses me as well.
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
Reviloo schrieb:
For knee walls between 1.0 and 2.0 meters (3.3 and 6.6 feet), 50% of the area is counted as living space (please correct me if I misunderstood something). 11ant schrieb:
Anything below one meter (3.3 feet) in height is completely excluded from the calculation, and between one and two meters (3.3 and 6.6 feet) the area counts as half. No, that applies to living area calculations mainly in residential buildings, for example. Also, I think your explanation is a bit tangled and therefore contains errors. Honestly, it’s quite confusing to read.
The floor area ratio (FAR) only refers to full floors.
To avoid counting a level as a full floor:
The 75% refers to the clear room height of 2.30 meters (7.5 feet) (assuming your figures apply to your federal state – others use two-thirds of the area or a clear room height of 2.20 meters (7.2 feet)?).
This concerns the definition of a full floor. Only the floor area with a room height of 2.30 meters (7.5 feet) counts; the rest does not.
So you could build a total of 200 square meters (2,150 square feet) including the terrace. For the attic floor, be careful not to get classified as a full floor:
That depends on the knee wall height and roof pitch. So, if walls were just lines, you could build 350 square meters (3,770 square feet).
But you probably don’t want that. If you take your 9 x 12 meters (30 x 40 feet) and plan with a knee wall of 150 centimeters (5 feet), just grab graph paper and draw the cross-section. Then you can quickly see how your little house could look if you stick to the 75% area rule.
Reviloo schrieb:
Roof type: GD What kind of roof is that?
The Auro gets its two-story classification from its two gables combined with a steep roof and knee wall.
What ypg wrote about the ²
The state building code states the following: “Full storeys are above-ground floors with a clear height of at least 2.30 m (7 ft 7 in). A floor is only considered a full storey if it has the height mentioned in sentence 1 over more than three quarters of the floor area of the storey below.”
The state building code states the following: “Full storeys are above-ground floors with a clear height of at least 2.30 m (7 ft 7 in). A floor is only considered a full storey if it has the height mentioned in sentence 1 over more than three quarters of the floor area of the storey below.”
ypg schrieb:
No, that applies to the calculation of living space, for example in apartment construction. And I think your explanation is a bit confused. That’s correct, and I never claimed otherwise: I only referred to the 1.0 and 2.0 meter (3.3 and 6.6 feet) measurements because they were mentioned in the original question, and they are relevant solely for living space calculation according to the Living Space Ordinance or DIN standards. However, the promotional materials for the house model in question state the living space figures, which I considered responsible for the critical assessment. So, to clarify again: whether areas are fully or partially counted only matters for certain living space standards. For a full storey, the clear ceiling height of 2.3 meters (7.5 feet) in the attic is decisive, or 1.4 meters (4.6 feet) average height for basement areas protruding above the original terrain. Areas under 2.3 meters (7.5 feet) clear height in the attic are therefore not relevant—except in Berlin and Brandenburg, which only recognize full storeys if they contain habitable rooms.
ypg schrieb:
What kind of roof is that?
The Auro achieves its two-storey nature through its two gables combined with a steep roof and knee wall. GD is probably referring here collectively to the category of pitched roofs. Why the Auro is considered a two-storey house with only a 75 cm (30 inch) knee wall according to the builder’s specifications—except in Saarland—I have not yet understood. I think, however, that if this is the case, it would be such a narrow margin that it could be compensated for by a bay window on the ground floor. Alternatively, one could consistently apply a lower vacuum knee wall of 50 cm (20 inches) or partially build knee walls. So, if the Auro is the definite choice, there would probably be ways to make it work. In any case, I see it as not far from a possible house shape here, so it may serve the original poster as an example of what could be built on their plot.
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
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