Since some parts of the image are sharp and others are diffuse, I am wondering if your lens was dirty. In daylight conditions, it doesn't matter too much if your lens is not spotlessly clean, but with night-time photography, even the slightest finger mark can cause the partial blurring that you have in your photo. Stopping your lens right down makes it even worse since each element of the image is only receiving light from the corresponding area of the front surface of the lens (and filter).

Clean up and open up, and you'll be fine.

Edit:

• Make sure that the rear surface of the lens is clean as well as the front surface. It's just as important.

• Remember to shield your lens from rain and moisture. That's just as bad as dirt. Use the biggest lens hood that you can lay your hands on.

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Why are you using f/16, for heaven's sake? What are you trying to achieve? Open your lens wide and set the focus to infinity. You should be far enough away from the building that it makes no difference.

I would recommend using a prime lens (if you have one) for this type of photography, although others may disagree. Prime lenses will have fewer internal elements than zoom lenses, and there should be less risk of lens flare and other distortions.