Recent research of Computest shows that in 17.444 buildings that make use of the well known KNX standard are vulnerable to hackers. The vulnerability is caused by the fact that these systems are connected directly to the internet without any form of authentication. This makes things like security, airconditioning and heating accessible to the outside world.
To check if this is the case in your building or home, Computest developed a KNX scantool that can be found here: www.knxscan.com. This page directly checks/scans your ip address for vulnerable KNX installations.
Read the full press release on the research here.