This guide will include:

Charge and time requirements with Repair Upgrade on the Engineer, without repair upgrade, and using the E build with a non Engineer class.

Turrets: 38 charge, ~7.5 seconds
Engineer Surveillance (Camera/Radar): 30 charge, 6 seconds
Walls: 38 charge, ~7.5 seconds
Refinery: 63 charge, 12.5 seconds
Barracks: 100 charge, 20 seconds
Vehicle Factory: 100 charge, 20 seconds
Armory: 38 charge, ~7.5 seconds
Radar: 88 charge, 17.5 seconds
Repair Station: 75 charge, 15 seconds

Charge requirements in excess of 100 charge are calculated rather than tested.
Requirements are approximately double of with repair upgrade. I say approximately because some requirements are changed in order to be increments of 5 by the game.

Turrets: 75 charge, 15 seconds
Engineer Surveillance: 60 charge, 11.5 seconds
Walls: 75 charge, 15 seconds
Refinery: 125 charge, 25 seconds
Barracks: 200 charge, 40 seconds
Vehicle Factory: 200 charge, 40 seconds
Armory: 75 charge, 15 seconds
Radar: 180 charge, 36 seconds
Repair Station: 155 charge, 31 seconds

Only times are included, due to there being no charge amount for E building. Engineer Surveillance is not included, but may be included at a later time.
Requirements are approximately double of without repair upgrade.

Turrets: 30 seconds
Walls: 30 seconds
Refinery: 50 seconds
Barracks: 1 min 21 seconds
Vehicle Factory: 1 min 21 seconds
Armory: 30 seconds
Radar: 1 min 11 seconds
Repair Station: 1 min 1 second