Place small sticks in a pile. Light a match. Using the match, light the sticks. As the flames burn through the sticks, add bigger sticks. Add even bigger sticks. Add some small logs, then bigger logs. Sit back, and wait a while. Now you have a fire, and can keep warm and cook dinner!

起火，生火！

"building a fire" in your statement is of literal meaning - "to set a fire". Thanks to Don for sharing us a detailed process on how to set one. :)