Survey of saddle roof knee wall height

  • Erstellt am 2021-12-09 14:14:33

11ant

2021-12-18 00:20:49
  • #1
The builder makes more profit if you pay more for the same effort or if he has less effort for the same price. You will pay more if you get more living space (according to DIN or the Wohnflächenverordnung — depending on how the builder measures and bills this "extra") — so you will pay more for more square meters, no matter how they come about. What is called "knee wall height increase" in the additional price list is basically "calculated additional area due to knee wall height increase." A "knee wall height increase" in the sense of "more rows of bricks under the roof slope, but with the same type of roof truss construction" increases the effort and the price. If you build a town villa, i.e., make the attic a full floor by a "knee wall 260" or "knee wall 100%," naturally more rows of bricks are built and more (also calculated) living area square meters are created. However, above the just-built walls there is no elaborate rafter roof truss, but a considerably simpler "lid" as a tied roof, which is cheaper to build. In a cross-comparison between country house vs. town villa, you regularly get the "town villa" cheaper at the same nominal size. In a comparison within the respective category of "more height 'on top'" vs. "more area 'on top'," you will get "more height" more cheaply because you can get it "on top" "individually," whereas more area is also built and billed "below" at the same time. All variants have in common that with "free planning" the nominal square meters are the calculation basis because they are the easiest billing measure for the contractor to handle and communicate. With the "replanning of a catalog design" it is different: here, more width is more expensive than more length, and a knee wall height increase with a roof pitch change is always more expensive than without changing the pitch (even if the attic space does not become "larger"). Simply put, every change is more expensive the more dimensions it affects. The worst case is "length and width and pitch." For the staircase, the construction, formwork, and crane handling are relevant price factors. Here, too, the first and second laws of gastronomy always apply :)
 

jerimata

2022-02-07 17:55:21
  • #2
So far, only windows and optical/furniture-related reasons have been explained here - I wonder if there are also technical reasons for a specific roof pitch (maintenance, rain, snow load)?
For example, with a standard house, we could choose between a 0.9m knee wall + 40º roof pitch versus a 1.25m knee wall + 35º roof pitch. Yes, no huge differences, but 1.25m does sound somewhat more practical, 35º is also supposed to be somewhat better in terms of photovoltaics, but do you potentially get significant disadvantages regarding tightness/maintenance and snow load, or are these magnitudes irrelevant – or should one really only consider space and appearance/windows?
 

11ant

2022-02-07 18:40:06
  • #3
No, just recently in post #37 I explained (also cost-) technical reasons! By the way, in alpine regions, the danger of roof avalanches is countered with low roof pitches. In lowlands, pitches of 35 or 40° DN will not significantly influence how long the snowflakes remain. The limit for a smaller selection of roofing materials lies at 21/22° DN, so far from 35/40°. 90/40 also reaches 125 cm inwards after about 42 cm, 200 cm is reached after 131 cm; with 125/35 you would have reached that height after 107 cm. So only choose 90/40 if the storage room in the attic is crucial, and otherwise 125/35 for all other aspects. That is all I can advise you without knowing your project.
 

Similar topics
23.07.2015Use the attic in the new city villa21
15.09.2015Your opinion on the floor plan of our planned city villa10
15.07.2016City villa floor plan - Your opinion on it?21
19.07.2016Eaves height of 6m for a city villa11
09.01.2017Floor plan – City villa 160 sqm34
27.10.2016Costs for construction project city villa, 1 full floor33
12.09.2018Development plan: Should the roof slopes of the dwelling houses be adapted to each other?13
04.09.2020Full floors in the timber-framed house with a 53-degree roof pitch.20
09.03.2020Attic with gable roof 22 degrees roof pitch31
09.02.2020City villa 170m² on 567 m² plot77
06.05.2020Liberation § 31 Building Code: Roof pitch, roof shape, roof structures15
08.03.2020House design city villa, 2 full floors, double garage30
04.08.2020Floor plan design city villa 190 sqm12
05.12.2020193 sqm urban villa with north orientation, is it sensible?38
09.12.2020City villa approx. 200 sqm with extension35
23.12.2020Porous concrete solid roof as a tent roof for a city villa31
03.03.2022What roof pitch is appropriate?10
28.12.2022Floor plan single-family house city villa approx. 240m² without basement132

Oben