. >> reporter: 64-year-old alex tannenbaum is busy building an elevator in his own home. >> i took this middle line and opened the shaft which i will put a lift in so that this house can really be an aging in place friendly house. >> he plans to grow old in his current neighborhood as long as he can and he is not alone. >> people want to age in place because they love their home it's a cheap investment. they love their neighborhoods and communities and the control they get. >> reporter: the trend is removing an estimated 1.6 million floems a housing market already in critical need of more homes for sale cording to the other houses built each year. >> there's a fail safe we can't get enough houses for people who want to put their kids in good school systems. >> reporter: not enough listings for the high demand of move up family buyers. it's not just homeowners like tannenbaum, others have no zblois for others because there's nothing affordable to move to. >> reporter: in some cases the math just works in favor of staying put. >> but if they have to spend another million dollars in order