Black and White - Or Colour? That is the Question

I'm working on a project called Juxtapositions. The images in the collection present buildings in Toronto that contrast with their surroundings: old buildings juxtaposed against new, different architectural styles or even two similar buildings painted different colours. Many of the images work just fine in colour, but some of them seem better in black and white, especially if the image is all about form. Here is an example - see what you think...

First: the original colour version

And Now in Black and White

Thoughts anyone?