Not my part of London but I drove near here the other day - I never knew it was there. It's a beautiful building and reminds me of some others with similar architecture in London.
There are some amazing buildings in different parts of the city with some amazing architecture. I can see why it is listed.
It's a little hidden away from the A4, so unless you notice the clock tower it's very easy to miss it.
Seeking out these under rated buildings in London can be really fun sometimes
I think I will do a search for some too. Perhaps I will post some soon.