How it should work:
15 minutes building revival: if team is losing building A and manages to hold for 15 minutes they get their building back fully operational with 100% health and 0% armor/shield (so it is more vulnerable and needs care/repair to 100%); if more than 1 building destroyed - it goes into queue and waits another 15 minutes starting from building A restoration time (building B destroyed, building A has 7 minutes left to revive so 7+15 = team gets building B in 22 minutes). Why it should work so?
This will encourage players into teamwork and more aggressive gameplay, not just afk repairs and constant siege, as enemy at the gate will need to press on, unless they want to lose advantage. For longer matches it will create "game changer" as team that can manage to hold back with building destroyed for 15 minutes can push enemy back with former strenght and prevail. If Yard is destroyed, this option is disabled for the team.
