If your house is in a hole - and they can go either way - then use a positive number to bring the lot back up to the right elevation. If it is up high on a plateau, like Kiko's friend's, then you would use a negative to lower the terrain. One thing more to remember is to set the terrain to 0 when you have finished.
I'm sorry to bring up a thread that was done & over with 3 years ago. Trust me, I'm generally not one to do that. In fact - this is honestly my first time doing so, but, I figured since my question is in regards to this quote as well as my problem being the same as the OP's that it'd make sense.. Sorry if it's a problem.
Firstly, I just wanted to say thanks for the solutions as it worked for me. For the people that may be having issues getting the cheat to work or looking up solutions on Google for the same problem as kiko94..or if you're like me - both...lol..be sure you're in Edit Town then enter the cheat - before placing the actual house/buildinging. i'vee tried this cheat so many times and it never worked for me...until I found out that you have to be in Edit Town. Also, you may not see a DRASTIC change if the house/building is too far in the ground/in the sky if you're using the 1 by 1 technique (ex. Setimportedterrainoffset 3...2....1 or -1..-2...-3..etc) if that's the case, go for a higher number (for lots in the grounds) or smaller number (for lots that are in the skies) I orginally just started doing it 1 by 1 but that took up a lot of my time due to the saving literally taking forever & 0, oddly enough, never flattens anything for me (but it has for other people so..). My solution that helped me with a mansion that was basically raised to the sky after trying both techniques (1 by 1....& 0), was: -11. I got tired of the saving taking forever and when I noticed that -1..-2..-3 was just very slowly going down, it upped it up a notch by going... -6 (Still wasn't level, but of a way to go but saw the difference as opposed to going 1 by 1)....-12 (by then the mansion was slightly in the ground) then -11. Fixed my problem. Obviously your numbers will differ from my mine but my point was if you have a house/building in the ground or raised to the sky, don't be afraid to skip a couple or few numbers. Now if it's slightly up or down, maybe even a little more than slightly then yes, 1 by 1 would probably be best.
I didn't intend to write any of that as there is a reason why I quoted Figwit but thought it would be a bit helpful since it's on topic and could be useful for anyone looking for solutions with the cheat not working or/and the terrain problem.
Figwit or anyone that may know the answer -
Do you put the 0, when done, right after you get done rotating & altering the terrain height (Before clicking on Accept)...or after you click on Accept? If it's the latter, do you have to be in Edit Town? I know you said after you have finished but finish...after altering the height & rotating (if needec) or finish as in after you click on Accept?