This is a remix from
http://www.thingiverse.com/thing:1757845
and
http://www.thingiverse.com/thing:751984
which has enough space for a Raspberry Pi 3 including an enocean or zwave module attached to the GPIO Pins
I created the enclosure with tinkercad, so if you want to modify the case, then go ahead:
https://www.tinkercad.com/things/drPk3PukiBO-openhab-rasperry-pi-3-enclosure