It occurs as if we often don't differentiate Past Perfect and Present Perfect, yes.
Only the outcome is important:
photos are ready
room is ready

We should use "был" if we want to emphasize the moment in the past.
Hence, Дом построен в 2012., is probably just shortcut for Дом был построен в 2012.
In the movie "The Big Lebowski", there is a scene, where Small Lebowski is presented with the photograph depicting Big Lebowski with Nancy Reagan, with a commentary:
"Снимок был сделан, когда Нэнси была первой леди!"