Physical access control
We (Omni) are currently using:
We are working on a new system for all of Omni.
Here is a list of existing hackerspace access control software with some notes for each.
Off the shelf
Custom hackery solution
Since none of the off-the-shelf solutions do exactly what we want, we could instead build our own. One way would be to use a z-wave smartlock and add our own control electronics for wifi / bluetooth / rfid. Unfortunately those locks start at around $150.
Another option is to build pretty much the whole thing from scratch from a deadbolt and a $17 3 V smartlock motor from Aliexpress (our spam filter is blocking Aliexpress links but go to their .com/item/4000226861796.html ). This would require some mechanical fabrication which seems like a bit much.
A simple but still lower cost option is to add e.g. an ESP32 and a Nordic low power bluetooth module to the cheapest possible battery-operated electronic deadbolt. If we want something with a replaceable and re-keyable mechanical lock core then kwikset sells one for $60 and there are some no-brand versions around for a bit less.
We could then have the ESP32 operate in low power wifi client mode and keep an updated access control list, then let folks open the doors with their phones using wifi or bluetooth where bluetooth would continue working as long as the lock has batteries. We could even potentially use the built-in buttons to wake up an RFID reader for a few seconds if that doesn't drain the battery too much. We would of course rip out the existing control circuitry.