I think I said earlier that I do not see the need for an additional layer.
You do not need the Lords as your second chamber if you have a UK Parliament as that becomes your second house and, as constituency work would be done by the Assemblies (they would probably be called something else, even Councils as they would be building on that) you do not need as many UK MPs as we currently have MPs in the Commons. Those running Assemblies could subsume the constituency work of the English MPs and do the county or city council work.
I don't have all the ins and outs worked out rosequartz, that is for cleverer people than me to suggest, but the "extra layer" tactic was used to scare voters in previous assembly elections. I understand why, as the current political parties certainly the two largest, will not want a devolved system. They would have to work much harder to bring together groups and would be much less able to steam-roller bills, that no one has ever voted on, through the(UK) Parliament.