Funcom. If you want to reduce massive base structures reverse the decay timer. The bigger the base the shorter the decay timer. With a set lower limit say a base consisting of 100 structural pieces or fewer equaling 1 week decay timer, but a base of several thousand pieces equaling 24 hours. Thus, if a clan consists of 10 players they should have someone on at least sometime within a 24 hour period to maintain the base(s).
Now would people just build in chunks, possibly, but good luck with that on pvp server.