Engineers are one of the most important units when it comes to defense or conquer objective points. So they need to be rewarded for their actions and taking risks to building different types of support elements, like building defensive sandbag forts or supplying the entire team with ammunition.
Engineers should receive points for following actions.
Barbed wire: +10 each unit
Sandbags: +10 each unit
Spawn point: +50 each Unit + additional points for spawning units.
Ammo box: +15 each unit + additional points each time a soldier does a pick-up.
AT stationary gun: +20 each unit + additional when other people use it.
AAA stationary gun: +20 each unit + additional points when other people use it.
Anti-tank blockade (Tsechenigel): 15 each unit.
Of course the values can set different, but this suggestion will force and support teamplay. Because the engineer will become a more interesting class to play and also to level up a little bit easier their campaign level.