ISO 14001 and sustainability reporting - worth it?

So we’re midway through our ISO 9001 journey and already our board is asking whether we should be looking at 14001 as well.

Apparently one of our bigger clients mentioned something about sustainability reporting requirements and now suddenly it’s on my plate.

Honestly I barely have my head around 9001 right now. Is 14001 actually useful for the sustainability reporting stuff or is it just another box-ticking exercise that looks good on paper?

Would love to hear from anyone in construction or civil engineering specifically.