@nprofile1q... The only real issue is the cost of retrofitting existing housing stock. But there is an easy win in lots of older homes. It's been common practice for a long time to put light fixtures on one or two low-amperage circuits that can use smaller conductors, and run thicker wire to the mains outlets in the walls around the house. So switching all the lighting to 24V DC would be pretty simple. The side benefit is that using plain LED light fittings without the rectifying drivers would mean greater longevity as well as efficiency.

The safety issue that comes up with higher DC voltages is that you need arc suppression in the switches.