[HELP ]Metric system

[Lust3r]

Hello there folks,
I'm now in all this Sweet Home 3D-ing, but I must admit that I like this program, a lot.
Now, after some time that I spent using it, I've noticed that length/height/width are shown in inches and feet.
I don't know how to change it to metric system, which would appear to be far easier for me.
Thank you for your reading, I hope someone will help me with switching to metric system- step by step. Thanks.

[Puybaret]

Select a unit of the metric system in preferences pane.