If they own an apartment building, how can they be lower middle class? Even if it's not fully paid off, unless they are upside down on the mortgage, they have wealth. And even getting a bank to approve a mortgage means you're probably not lower middle class.

Do you mean they look and act like lower middle class, because that's how they grew up?

Or do you mean the margins are very bad so they have to do all the maintenance themselves and the profit is actually very low? Why is that?