In time, this could be a really good way to go. For those who doesn’t know, it could be like this; you have a “main base chest” where you need to store building material based on the building type (T1-T3, south or north) which is used to indirectly repair the base from decaying HP over time. So if you build a base without adding this decay upkeep materials it will lose HP in line with the decay timer, and reach 0 HP when time is up. (Or, scrap the decay timer and only use upkeep)
Here is a few reasons for it:
When you are done building the base, you dont have any more to do on the building front - now you do.
Prevent people from building massive bases that put a strain on the server preformance - as the upkeep for a massive base would be too time consuming. (Upkeep cost shouldn’t be too expensive though)
Making it possible to remove abandoned bases cheaper before their decay time is up.
Base will auto repair (slowly and perhaps with a delay) after the base is raided. (Additionally it should be a delay on manual repair on a live raid - say 30 seconds - so that you cannot just out repair the explosive jars.