Sorry to sound sarcastic!
Officially there should be some information at the relavent townhall. However, as I understand, it only shows what the land is officially designated and secondly if someone is applying for permission to build.
BUT, no doubt better informed people on this forum will discuss the various ways of getting away with building something without permission.
Unless you are right by the beach, by a golf course or something is already built in front, it is difficult to guarantee no future construction.
😈