Is it a requirement for single family housing to have gas and 220 electric hook up in the laundry room

If u have electric dryer, u would not need a gas hook up.

If u have a gas dryer, u would not need 220 unless needed for another appliance.

Chuck

It is not even a requirement to have a laundry room.

But no they only need one or the other. Some homes would not even have gas available