A selection of a few points of interest from the following standards and regulations:
 EN ISO 14122-4:2016
 ČSN 74 3282:2014
- The distance between the rungs must be the same between 225mm and 300mm .
In justified cases, a distance between 225 and 400mm may be allowed. 
- The clear width between two rungs shall be between 400mm and 600mm.
- The shape of the rungs: The footing surface shall be flat and => 20mm. Circular crossbars are not allowed.
- Distance of the last rung from the exit level  :
- Distance of crossbars from structures  :
- Distance of gable from structures  :
- Space dimensions with permanent obstacles  :
- The maximum length of a ladder with one branch is 10m. Longer ladders shall be split into branches so that no branch is longer than 6m. 
- The ladder shall be fitted with a fall protection device (e.g. safety basket) if the ladder branch length is greater than 3000mm  .
- Safety basket:
Consists of stirrups (e.g. FL50*8) and a minimum of five longitudinal members (e.g. FL50*5) equally spaced around the perimeter of the stirrup. The stirrups are generally attached at four times the distance of the cross members (max. 1500mm) .
- The lowest part of the safety basket must be at a height of => 2200mm and <= 3000mm  .
- At the exit, the gratings and the safety basket must extend above the exit level to the height of the guardrail, at least 1100mm. Where there is a handrail at the exit level, it must be fitted with a self-closing safety gate. 
- Grilles should be fitted with an easy to grasp handrail at the exit. 
- Example of a front exit ladder with handrail  :
- Example of a front exit ladder without handrail  :
- Where the ladder is ascended sideways (side exit), the ladder shall be extended from the height of the last rung to a distance of six times the distance of the rungs, but not less than 1680mm above the exit level. 
- The rungs are designed in round steel, square steel or special polygonal sections. Circular cross-sections are not recommended for permanently wet environments. The diameter of the crossbars shall be minimum 20mm, maximum 35mm. The tread surface of the rungs of ladders requiring access in damp or wet areas must have a non-slip surface. 
- The limiting deflection of the rung from the plane of the ladder in the perpendicular direction shall be not more than L/200  :
- Recommended minimum rung profiles for a ladder with two rungs (max. length 12m):
Vertical distance of supports  :
2400mm - L50*5, UPN50, CHS42.4*3.2
3000mm - L60*6, UPN50, CHS48.3*3.2
4200mm - L70*7, UPN65, CHS60.3*3.2