Air carrier Captain reported there were no guide lines for parking or taxiing on the East Pad at SAN and it was difficult to determine if the aircraft was clear from other objects. Another air carrier approached the area and also could not determine if there was proper wing tip clearance. Airport Operations had to be called to clear the conflict.

Narrative

Upon landing in SAN; Gate XX was occupied. Ground told us to hold on the East Pad facing west. We complied. I turned into the Pad giving me enough room to turn out and rejoin Bravo taxiway to get to our gate when it was clear. There are no lines that accommodate aircraft holding in the Pad. I parked in the middle of the Pad with room on my left wing away from the construction fence. This put my right wing tip close to the non-movement line. But with a proper parking spot and line I couldn't be 100% sure my wing tip was clear. As we sat; Aircraft Y was cleared to taxi on Bravo to Runway 27. He stopped short of our position not knowing if his right wing would clear our right wing. I could not move forward due to service trucks being parked between the west end of the Pad and the alley of Gate XX. Airport Operations was called to move all the trucks. Airport Operations watched out for our left wing tip on the fence line. I was able to maneuver left and then straight out to Gate XX after giving room to Aircraft Y off my right. I proceeded to taxi into the gate without any further issues. If we are told to park in the East Pad; there needs to be guide lines and spots that ensure wing clearance with Taxiway Bravo and the construction fence line. Also create a better spot for service trucks and operations vehicles [to] sit.