Base Destruction is too easy, carries effectively zero risk, and costs only time.

Griefers will be too numerous and too patient to care about the current small costs of base destruction (Time, and tool durability). In order to discourage casual griefing of base structures, particularly by lone players, it needs to be structurally dis-incentivized by making it more difficult and more risky, but preferably without the introduction of unrealistic or immersion-breaking limitations like arbitrarily increased action times or spawn rates.

My suggestions are the following:

• Make destruction require a stamina cost comparable to sprinting (requiring the usual food/water costs associated with other tiring tasks).

• Make destruction a noisy process that continuously attracts local AI threats (Infected/Aggressive Wildlife) and other players.

Ideally a player would be able to defend their own construction, but the reality of this just being a game means the most realistic approach is not available. DayZ is, however, occupied by hostile AI entities that can impose risk (and inconvenience) in place of a player. Smashing walls with a sledgehammer should be comparably noisy to an active gun battle, and should attract local infected. This would make it difficult for lone players to dismantle bases as they are forced to break off their efforts to deal with threats. If the threat needs to be exaggerated, the option of spawning local enemies could also be explored.

The cost in food and water would also encourage hostile players to instead choose to penetrate weaker parts of a fortification rather than deal with the survival costs of dismantling an entire base. I believe these methods are stronger passive ways to dis-incentivize griefing than more direct routes like simply making base components extremely tough to break, or the items required to do them exceedingly rare or fragile.