Solved Ideas to what this lovely plant is?

I have a lovely plant, no idea what it is. It does seem to like our garden as it's taken over the back of the greenhouse. Also the bees love it. My partner is not so keen though. Can someone let me know what it is so we can look at training it.
Many thanks.

 

Hypericum or Saint John's Wort or Rose of Sharon

We have a lot of it in the business park where I work, planted together with Lavender. The colour combination is stunning!

 

Many thanks.. yet more St John's Wort. Never realised there were so many differing varieties.