Using "Select by location" with percentage

Question

I have two layers, one layer with isochrones with representing driving times from certain locations and one layer with postal code area's.

What I want to know is which postal code area can be reached with 5 minutes of driving time. The problem is that some postal code areas are crossing with the isochrones layer by a very small amount.

I wanted to ask if it's possible to select the postal code area's which are covered by for example 30% so the area's that can be reached within 5 minutes is more accurate?

Answer 1

1. Overlap analysis to add overlap area and percentage columns
2. Select or Extract by expression those with a percentage >=30

With my data the expression is

"Multi-ring buffer (constant distance)_pc" >= 30