Chicago landlords are enjoying tight vacancies and solid NOI gains, but highly concentrated development in robust submarkets like River North could stifle additional occupancy gains and rent growth, according to PPR senior market advisor Glen Marker. (Looks like he's hiking around the original multifamily development: caves.) Record-high rents for new downtown Class-A product (like$3.09/SF at K2, pictured below) raise an affordability question in the CBD, he says. Average asking rents for todays downtown Class-A command about 38% of a typical household income, significantly higher than the historical average of 32%. The biggest question for developers building on top of one another: Were your pro formas realistic in terms of rent growth and lease-up period?

Chicagos delivering nearly 4,900 apartments this year (and, so far, 2,250 in 2014), with 2,800 located downtown. That's more than the entire Phoenix market will receive this year and represent market rate inventory growth of over4%, among the highest in the US, Glen tells us. An interesting note: Last year, national apartment sales skyrocketed to $69B, but Chicago numbers were middling at $2.3B. Why such little sales given such strong fundamentals? Glen's best guess: All the capitals jumping into development--just walk around Streeterville to see cranes proving his point.

The kids text me "plz" because it's shorter than "please." I reply "no" because it's shorter than "yes." Send your news to Catie Dixon, catie@bisnow.com, or Tonie Auer, tonie@bisnow.com.