I used a preset from Perfect Photo Suite 9 here, Vivid Dream from the Hint of Color group in their Black and White module. I then mask out a lot of the B&W effect revealing the color again. The building was in fact pretty monochromatic to start with. I generally dislike cliché selective color (where the photograph is converted to b&w except for a single object like, say, a red flower) but I do sometimes like this effect where the image is almost B&W naturally to start with.