Don't listen to your realtor when they say that advertised apartment is really a two bedroom if you just throw up a wall in the middle of the living room. Though the DIY separation could make your rent cheaper, the city is cracking down on a previously widely ignored code about separation walls. Hundreds of walls thrown up without Department of Buildings approval are being taken down, and new renters are being told that if they want to separate rooms, they must use bookshelves or other partitions that don't reach the ceiling.

The city says the walls must not block exit routes, and Tony Scalfini of the DOB says "each apartment is generally required to have at least one room of at least 150 square feet." (Though anyone who's ever been shown an apartment with windowless, triangular bedrooms knows that latter rule is total BS.) Realtors and landlords are already feeling the sting of the enforcement, which most likely lowers the number of bedrooms that can be advertised. Gordon Golub of Citi Habitats told the Times, "Landlords are all trying to come to some sort of conclusion as to what they are going to do in allowing any walls or a different sort of wall that might go up, and it is affecting brokers and customers."

Roommates everywhere are now being forced to take down even landlord approved partitions if they haven't been approved by the Department of Buildings. Many must erect flimsy or incomplete partitions instead, which will most likely result in lots of roommate "breakups" after they hear how loud the other gets during sex. But if you and your four roommates decide to make a three bedroom out of a studio, just make sure at least a few of you are related. Otherwise you could really get into trouble.