2.4 GHz versus 434 MHz transceiver for home automation
In my (short) experience, 434MHz (or even 915MHz) would be much better getting through obstacles than 2.4GHz.

Please mind that an obstaculized 100 meter range is quite large for the usual hobbist module. Also, antenna directionality is important: if the antenna is omnidirectional you might be radiating power to directions you don't need, so take that into account for your link budget.