[Suicide Junkie]

For every turn you spend on Emergency Build (150% rate) you must spend one turn on Slow Build (25% rate)
Once the slow-build time is up, your SY returns to normal.

As for resource shortages, you can mothball some ships and bases that you don't need, and replace some research facilities with miners.

For longer-term economy building, you can place Value improvement facilities on your planets (planet utilization tech 4,5 and 6)
Value improvement fully stacks, so two facilities increase value at twice the rate as one.

Also long-term, is atmosphere converters. (planet utilization 7,8 and 9)
When placed on domed worlds, they will change the atmosphere to remove the dome and give you 5x more facility slots.