Ah just seen your follow up note.
I agree that any capacity increase is unlikely at least for a few years.
We'll see. I literally phoned up my old man (ex director of building control in local authorities ; see previous). I was surprised by his "NO" (emphatic) about the safe standing
He started quoting post Hillsborough to me (he was in local gov back then). They will want lots of evidence to show that the club can control fans and keep them safe, if they allow greater than 1:1
The local authorities and emergency services have a lot of say on the safety certificate and the licencing of the ground and SGSA issue guidance.
Thats why I think 1.5 won't be granted based on what @Tom Hughes highlighted. It'll be 1.3:1
They will always go with the safest most conservative, option in terms of it and Tom in his post highlighted the technical points versus the green book.
Yes.... 2 × 350mm + 50mm for rail seat corresponds to a seated tier of 750mm. This is the bare minimum for greater than 1:1 ratio. The green guide still has a minimum personal spacial allowance. That only equates to 1.3 to 1.5:1 ratio for 750mm seated tread depth. Most German stadia where rail seats are 800 up to 1000mm for that reason.