[snip]

Just in case it's not impinged on you, planning permission and building
regulations seem likely to be relevant so - depending on your local
authority's willingness to engage informally - you might want to start
by what tends to cause them least problems.

https://www.planningportal.co.uk/inf...cts/11/decking

Yes, we're aware that planning and regs apply. The above site is
totally useless, all it does is tell me that decking more than 30cm
high requires planning permission which we knew already. There's
nothing at all about balconies or outside stairways.

--
Chris Green
·