All of these devices are actually in a single network as defined by the 255.255.0.0 subnet mask and you have not actually subnetted, rather you have administratively defined a standard numbering scheme.
This only actually becomes subnetting once you take your network and break into down into smaller networks, sub networks.
-your network for your HQ is 172.16.x.x (16 bit network)
-you assign 172.16.1.x with a mask of 255.255.255.0 to DHCP
-you assign 172.16.2.x with a mask of 255.255.255.0 to dedicated pc's and servers
* you will need a router or dual homed device to get information from one subnet to the other and back again. The joys of subnetting ;)
Essentially you have taken 1 network with a possible 16,000 addresses and you have provided for 254 networks (technically sub networks) with 254 devices each within the same address space.