Workshop

The Workshop is the most used Tech building, it unlocks explosive/fire type weapons and is equivalent to the Armoury tier-wise.

Main use
It is used to unlock various things. The Workshop unlocks 2 base Weapons, Mortar and Swarm Missiles, and also allows you to build the Munitions Plant and Factory.

You generally want to place it at the start of the game, so you can build the next tech or start making Weapons.

Other info
Tech buildings are some of the most expensive buildings, but also the most expensive to repair. Because of their high HP, it takes a long time to repair, and because of their high cost, it takes a lot of metal/second to repair. In the end, it's extremely expensive.

Workshop is the most used tech, because of how easy it is to place on any base fort, because of its horizontal shape.

As all tech buildings, it takes a lot of time to build so you can make defenses before your opponent has weapons.