This answers a question I saw on here.
I very much doubt if I'm the first to figure this out. I bet hundreds of sim players more code-savvy than me have sussed this out by now, but here it is anyway in case people were annoyed, like I was, the first time they suffered the dreaded beach lot bug in apartment life - where your apartment on the beach sinks and the sea floods it.
To fix the problem, this is what I did:
Opened Simpe to check out the lot descriptions of the apartment/beach lot into which I just moved a family. There were two copies of the same lot. One I figured was the main one, the base one, if you like. The other one was the parallel universe one into which I just moved my simfamily. Checking the elevation number of that one I could see that it was different. It's the Z: box in Simpe. So all I had to do was change it, make it the same as the other lots. The correct elevation is: 315.9375. And on returning to the game the apartment/beach lot was correctly elevated. Seemed simple, or even SIMpe

... well, until I realised that every time I moved a simfamly into an apartment on the same lot, the same thing happens and you have to correct it for each family.
I hate Simpe though. It's so slooooooooow on my machine that it usually just gives up and crashes. Frustrating.