"There is no builder hero in the team." What is a builder hero?

There is a Team Tip before the game starts saying

There is no builder hero in the team.

According to the official website, there are only 4 character classes:

  1. Offense
  2. Defense
  3. Tank
  4. Support

4 classes

I guess that builder is a sub-class of support, but what is a builder hero exactly?

Is there an official source or a wiki article to read about this topic? Can someone list all the builder heroes?


Torbjörn and Symmetra are the builders. They build turrets. This is what the warning message is referencing.