In the UK, photographing buildings, sculptures, and works of artistic craftsmanship that are permanently situated in public places is generally allowed, and taking/selling such photos is typically not copyright infringement. That said, the exact rules vary by country, so EU-wide or worldwide answers are not uniform.

A few cautions:

• Commercial use can raise extra issues beyond copyright, including property releases, trademark, contract, trespass, or unfair competition concerns.
• The safest approach for commercial use is to get a release when possible.
• Some works have separate protected elements even if the structure itself is public. A common example is the Eiffel Tower: daytime photos are generally fine, but the nighttime lighting design is separately protected and may require authorization.

So: in the UK, a public sculpture permanently installed in a public place is generally photographable and saleable, but exceptions exist and other legal rights may still apply. If the image is for commercial licensing or advertising, check local law carefully and consider a property release.