Correct Answer - Option 1 : 150 to 180 mm
Explanation
General requirement of a stair
|
Min rise (mm)
|
Max rise (mm)
|
Min going (mm)
|
Max going (mm)
|
Private stair
|
150
|
220
|
220
|
300
|
Utility stair
|
150
|
190
|
250
|
400
|
General access stair
|
150
|
170
|
250
|
400
|
∴ Rise vary between 150 mm - 180mm is the appropriate answer,
The normal relationship between the rise and the going is that 2 x the rise + the going should be between 550 and 700 mm.