How to calculate height of stair rises?

[ozseating]

should the top rise on a set of stairs using 175mm rises be 175mm from B the bottom part of the door surround or T the top part that is 5mm higher.

[JacobZ]

Hi @ozseating,

Thank you for your question.

The rise in stairs should be consistent on the front edge of the stairs to avoid tripping and missteps. I would say measurements should be in relation to B as this is the leading edge of the stairs and you put more of your foot on it than you do T.

Allow me to tag @Nailbag, @TedBear and @Jewelleryrescue for their thoughts.

Let me know what you think.

Jacob

[Nailbag]

Hi @ozseating 

If T represents the top of the step, then 175mm down from that, is your next steps and so on. B to me in the photo looks to be a slight forward profile of the top step having no bearing on what you would step on or as a trip hazard.

Nailbag