Galaxy S4 unrooted, yes.
Make a new profile, then select State, then Net. Select Wifi Connected, then select your home Wifi. Give the new profile a new task and select Display, Keyguard, Off. Long press the green arrow on your new task and select Exit Task. Display, Keyguard On and that's it.
So when you're connected to your home Wifi, lockscreen is off - otherwise it's on. I've not done it, but you could select Time instead of State and pick start and end time to turn off lockscreen.