How to run Update() from an abstract class?

I have an abstract class that checks if a Structure is being built. It works if I run it from the child class but when when it's in the parent class, the debug wont even print anything. Any ways to fix it?

     protected void UnderConstruction()
     {
         int n = 0;
         Debug.Log("Under Construction");
 
         if (builders[buildingConstructor - 1] == null)                  //Check if builders array is full
         {
             foreach (Thinbloods worker in PopulationManager.peasants)
             {
                 if (builders[buildingConstructor - 1] != null)         //Break for loop if builders array is full
                 {
                     break;
                 }
 
                 if (!worker.IsWorking())
                 {
                     builders[n] = worker;
                 }
 
                 Debug.Log(builders.Length + "******");
             }
         }
     }
     
     void Update()
     {
         Debug.Log("@@@");
         if (isBeingConstructed)
         {
             UnderConstruction();
             isBeingConstructed = false;
         }
     }