well Screech would be very happy to implement something like that, we havent been to find any that work yet, feel free to point me in the direction of any if you have links :)
We do however have an addon that tells us who has built what, but after some testing it doesnt appear to be working correctly at the moment...

Just to clarify this a little. Screech is counting Hangers / tanks as radtowns (any NPC building)

Obviously its hard to count the boundaries for these areas so players will have to use a little common sense (I know, bad idea) If you dont want pvp, dont go anywhere near these areas.

Also, Red bears / wolves tend to spawn close to the pvp areas, but are NOT counted as pvp areas.

*Edit* if anyone has any issues with these rules or suggestions please just let Screechout know & it can be discussed