gdn[ip] - ice plant (Sedum spectabile)

aka Hylotelephium spectabile, Butterfly stonecrop.

Can grow to 18" or slightly more, with pinkish flowers which are attractive to butterflies - prefers bright sun and a well drained (sandy) soil.
Despite appearing to be a succulent, it is actually classed as "hardy perennial" and is able to withstand frosts.

Bought "on spec" from a very small local plant / garden centre a year or two ago.
en.wikipedia.org/wiki/Hylotelephium_spectabile