In years after the financial crisis economists started to propose negative interest rates as away how to escape from a liquidity trap. Negative interest rate was considered to be impossible butfew countries have already set them below the lower zero bound. However, it has been done onlyin the central banks but not in the commercial banks. The main thesis of this paper is that lowinterest rates can inflate a housing bubble and as a result negative interest rates would only inflateit more. First, proposals how to make interest rate negative even in commercial banking arepresented in the paper. Then we discuss general consequences of negative interest rates such asredistribution, initiation of a business cycle and most importantly, inflation. Finally, we look at thehousing market and present theoretical and some empirical evidence of a possible ongoing bubble.The theory suggests that the negative interest rate would inflate the bubble necessarily.Consequences of a later decrease of housing prices have to be taken into account whenevernegative interest rates are proposed.