Roger Hayter wrote:

My impression is that building control may not have had very much
input:

I'm building* a house that requires a retaining wall and building
control have confirmed they have zero interest in the retaining wall,
other than guarding against people falling off it, and even they're
"guidelines" rather than hard rules from part K.

https://ibb.co/0BLp1bT

Can't see them rocks going anywhere, but depending on what's on the
other side, it might not satisfy the fall protection "guidelines".

Mine will be "one ton lego" blocks, they come in various designs that
loosely interlock and doesn't need any formal design for walls up to 2m
high, you can just buy them and stack them, above that height the
supplier designs/approves.

https://redi-rock.imgix.net/media/images/Texture_Pages/Redi-Rock_Retaining-Walls-Cobblestone-dimensions.png


[*] it's been on pause for a year.