Does anyone know of any legislation or design guidance that would apply to the required height of a theatre balcony railing to prevent audience members from falling.

For England & Wales Approved Document K

https://www.gov.uk/government/publications/protection-from-falling-collision-and-impact-approved-document-k

Approved Document M Part 2 covers access and use of buildings other than dwellings

roberm

To give some context to Brian's comment, I live in a terrace of 20 Victorian townhouses which are B Listed which each have a narrow flat roof below the front sloping rooves.

One property has permanent railings at the edge of the flat roof which will have been installed as an afterthought and almost certainly before the Listing of the whole terrace.

The railings at the one property are nowhere near the height that would have been specified in OLD Building Regs, let alone the 1100mm which would now be the standard. The railings in place would probably fail the appropriate lateral load test as well!

However, were I to propose ANY railings at the edge of OUR flat roof the Council would simply say NO on grounds of ruining the appearance of the terrace..