Originally Posted by MrFatbooty

Most condominiums have a monthly assessment based on your share of ownership of the building. The more square footage you have, the more assessment you pay. You pay the assessment to the condominum management company. Property tax is separate because you pay it to the government, and the management company generally does not pay it on your behalf.

You can also get hit with special assessments if some kind of maintenance needs to be done to the whole building. For example my grandma has a 2700 sq foot condo (it's actually two condos above each other with a hole cut in the floor between em and connected by a spiral staircase) in this old building in Chicago, and right now they're doing something ridiculously expensive like rebricking the whole exterior. She has to pay 60 grand over 3 years--the projected length of the work--in addition to her regular assessment because she has a lot of square footage. Most people in the building have more in the range of 1200 to 1500 sq ft so for them it's slightly more affordable.

So when condo shopping it always pays to look at how old the building is and how likely it is to be getting any special assessments in the near future. Also stuff like doormen and other community amenities usually tend to make for higher assessments.