In a transaction rife with truth-stretching, real square footage is an elusive number.

Designer Betsey Johnson—she of the flamboyant mane and offbeat fashion line—is leaving her two-bedroom penthouse in the West Village and has put it up for sale.

Buying a townhouse usually means giving up certain creature comforts. This property, whose façade is designed to look like a typical Harlem house, is part of an unusual project: a condo townhouse with amenities.

And other things not to say in your co-op-board interview.

The 5,725-square-foot penthouse at Morton Square that Ashley Olsen bought and renovated with her twin, Mary-Kate, years ago just went on the market for a little under $12 million.

Little distinguishes these two brand-new condos. Finishes are both top-shelf, as are the services. So what accounts for the colossal difference in price?

All those new-condo buyers are drawn to neighborhoods with the best public schools—which are then nearly destroyed by new kids.

Your broker does. And your board package, full of financial data, could be catnip to identity thieves.

Broadway producer Daryl Roth has, along with her real-estate-mogul husband, Steve Roth of Vornado Realty Trust, just sold their ten-room co-op at 800 Park Avenue for $9.5 million.

If this 129-unit condominium’s residents aren’t in shape when they buy their apartments, they will have no excuse after they move in.