Well, if you cannot find the specification on any prospective suppliers web site then you don’t really know what you are buying. It could be a shed with some insulation built out of 2 x 2 timbers with a poorly designed base. It could be a great looking designer garden room with no consideration to acoustics and thermal standards.
You really do need to dig down (Excuse the pun) and understand the specification of what you are buying. Even some of the best- selling garden rooms in the UK do not fully reach our specifications. Some, we would consider poorly insulated sheds. Looks are not everything, specifications are.