I am trying to change the class of an apartment building from low to high that I want to become my wealthy elders' retirement community.

I enetered the lot and used the cheat changelotclassification high, saved, exited to the neighborhod, and then re-entered the lot. To see if the cheat worked, I entered the cheat printlotclass, and it showed me that the class was high. But then when I moved a family in and rented them an apartment, the wrong group of townies started moving in and when I checked the lot classification again it ws back to low.

How can I get the cheat to work?

If I remember correctly, the cheat doesn't really work properly. The Lot Class really consists of two separate pieces of information: a flag to say whether to use the calculated value or whether to override that value, and a numeric value which will override the calculated value if the flag is set. Unfortunately, there is no cheat which will actually set the override flag, so usually the value disappears when you exit the lot.

If you want to set the value so that it will stick, you need to use SimPE to set the appropriate flag and class value. Alternatively, you can use the LotAdjuster. Let me try to get you more information.

[Update:] Here's a link to the relevant discussion starting around post #2106:
http://www.modthesims.info/showthre...181#post2025181

My version of SimPE doesn't have the lot class fields in the Plugin View, so unless it's been changed, you'll need to go into the Hex view and find the correct location using this information:
http://www.simswiki.info/wiki.php?title=DESC

For the LotAdjuster, I'm attaching a snapshot of the parameters that you need to use. If you select the parameters shown, the LotAdjuster won't do anything except set your Lot Class. Be sure to backup first, just in case.

You'll need to experiment with the Lot Class Value. We don't have an algorithm for determining what value is needed for Low, Middle, or High class, since it varies based on the type of building. However, the research discussion that I linked to above should give you an idea as to values:
Note that these are just the default values set by the game. If you set the lot class value to the value shown and you continue to get the wrong class of sims, try changing the value. For example, to ensure a high class apartment building, you could try 900,000. To ensure a low class one, try 1.

Also, remember that the lot class is affected by all other buildings within a circle around your lot (6-7 tiles in every direction). Alternating high- and low- class lots will not have the best effect. It's better to have a low-class area with all cheap lots and a high-class area with all expensive lots.

Ok, I've downloaded the Lot Adjuster, and I've selected the neighborhood where the lot is located, but I don't see any apartment lots listed.

Oh, right. I think that the LotAdjuster skips occupied apartment lots because it's a really bad idea to expand or shrink them. Is anyone living in the apartment building?

I suppose that I could update the LotAdjuster so that it disables most of the functionality for occupied apartment lots, but still allows you to change the lot class.

Let me look into this. Assuming everything goes well, I should be able to get you a new version of the LotAdjuster within a day or two.

OK, I've updated the LotAdjuster to allow you to change the lot class for occupied apartments. Note that occupied apartments have the same name as the apartment building, followed by the family number and name.

Sorry that it took so long. This was a more complicated change than I expected.