A real estate brokerage (or real estate investment firm) that sells primarily condos in a big city. Could also be the name of a condominium/apartment complex that offers nothing other than 1-bath units.

AS A REAL ESTATE BROKERAGE
“I bought the condo sight unseen through OnlyOneBath.”

AS A REAL ESTATE INVESTMENT FIRM
“OnlyOneBath bought my condo for just under $1 million.”

AS A CONDOMINIUM/APARTMENT COMPLEX
“Each unit at OnlyOneBath has a balcony.”

Welcome to New York (Taylor’s Version)… or Seattle… or Portland… or San Francisco… or San Diego… or Boston… or Miami… or wherever else 1-bath condos are common.