[Tagging] RFC - Feature Proposal - area of steps for pedestrians. -inconstancy across the step face.

Warin 61sundowner at gmail.com
Fri Mar 29 21:42:00 UTC 2019

```On 30/03/19 05:16, Christoph Hormann wrote:
> On Friday 29 March 2019, Martin Koppenhoefer wrote:
>>> * you should be aware that you can't uniquely define the shape of a
>>> two dimensional surface in three dimensions exclusively through the
>>> shape of its outline.  You can do that in 2d (provided what you
>>> have has a defined outline) but not in 3d.  That is simple
>>> mathematics.  So you'd have to document what assumptions you make
>>> regarding the shape of the surface, otherwise the meaning of your
>>> proposal would be ill-defined.
>> the general assumption for stairs is that all steps have the same
>> height and same "depth".
> That would not be a very sensible assumption since that would be
> impossible for any stairs where the upper and lower end are not
> equidistant across their whole length because then not all steps can
> have a constant depth.

In this case the stairs can have a different number of steps from on side to the other.
This keeps the same 'rise' and 'run' (technical step terms for 'depth' and 'height') the same for all the steps.
Making the step rise and run is important for safety .. it is also cheaper!
Think you will find most modern steps follow this method of construction, at least the ones I have come across do.

What of the case where the stair rise/run is not constant?
Document the rise/run on each lateral ... assuming that the change across the step facer is consistent.
If it is inconsistent, separate the areas at the line/s of inconsistency.

```