Advanced Construction Bot is a unit that opens the door to the T2 economy and high-level defensive structures. 

In most situations when you get one, start upgrading your:

1. T1 metal extractors to T2 Moho mines
2. Build Advanced geothermal powerplants
3. Build fusion reactors in combination with advanced metal makers. 

It has a higher buildpower than its T1 version and boosts your metal and energy storage by 100.