Thank you for the very nice comments which for me a s a reltive newbie are appreciated.
I have posted the original below so you can get a feel for the blandness of the original shot.
As for the workflow I used PWL (painting with light, illustrated look and also then applied a filter - posterise (very slight just to sharpen edges etc)
I obviously had to cut the building out to create a black background and did that with Rusell Browns advanced. Had to do that because of the edges etc.
If anyone wants the actual psd file I am happy to send as that is not a problem. I have also posted below another work from the same day and which I treated differently - thought you may wish to have a look.