There has been general research in the multifamily sector suggesting that additional units will turn into inventory that will negative affect future rent increases and vacancies. But average results and projections from them fall short because nothing in the country is that evenly distributed, as a virtual U.S. meeting by NAI Global, hosted by Arthur Milston, senior managing director and co-head of the Capital Markets Group, shows.

First, there are many metros still seeing continued employment growth and rental rate increases, with participants mentioning Austin, Charlotte, Tampa, Orlando, Phoenix, Nashville, Raleigh, Dallas, and Houston. All unsurprisingly in the Sun Belt because that's where demographics have shifted. And, pointing to a GlobeSt.com story, they noted that RealPage data showed apartment construction driving inventory growth in 15 of the country's top 50 metro markets.

One example was Dallas/Ft. Worth which sees a pipeline of more than 74,000 apartment units, an all-time high for new construction.