With Chicago on pace to deliver nearly 6,600 new apartments in 2017, the consuming habits of the Windy City’s growing number of renters matter more than ever to landlords and developers. Hoping to make sense of the latest trends, a new study from Enodo looked at Chicago’s top five most frequent building and in-unit amenities and correlated the corresponding effects on monthly rents.

Citing a 55 percent frequency, the report found that a pet-friendly policy is the city’s single most common building amenity and fetches an extra $34 dollars compared to properties that prohibit animals. Meanwhile, the addition of a fitness center—available in 39 percent of Chicago’s multi-family rental buildings—brought the highest average rent increase of $53 per month.

The 35 percent of Chicago apartment buildings that offer a laundry room, however, saw a negative swing of $9. While still preferable than schlepping to laundromat, the downturn associated with laundry rooms is likely to intensify as in-unit washing machines become a ubiquitous expectation.

On the in-unit side of the equation, hardwood floors were the most common amenity but hardly the most lucrative for landlords. That honor went to units that include a balcony or patio space. According to Enodo research, a typical Chicago tenant is willing to pay an extra $42 for his or her own outdoor space.

Methodology: According to Enodo, the company quantified the impact of more than 350 different amenities affecting rent for six million apartments nationwide via a Gaussian convolution algorithm.