Mike: I agree with Howard on the use of the buck converters. These are switch mode power converters that run without generating a lot of heat. And the output voltage can be adjusted to achieve the 4.5 volts (or whatever) that you desire. The input voltage must be higher than the output voltage so your 12-14 volt supply would work out perfectly.
You didn't say if your power supply is AC or DC. If it's AC, you'll need a buck converter that can handle the up front rectification from AC to DC. Fortunately, there are buck converters that include a bridge rectifier built into the module. This is the type that I bought, pictured below. I used 12 volts AC input from a train transformer and got out a nice steady 5 volts.
These are currently available on eBay for about $3 free shipping from Asia.
If your power supply puts out DC, then you won't need the bridge rectifier and you can choose a DC-DC buck converter that costs even less. However, the above unit will work with either AC or DC.
You may need to get more than one with all of the buildings that you've got. Steady amperage is going to be lower than the 2.2 max that they advertise. I would expect about 1.5 amps per unit.
