In the first quarter of 2017, single-family homes in Philadelphia increased 5% in value, adjusted for seasonal and quality variations. It is the largest such jump in the city's market since 1980, but the rising tide is not necessarily lifting all boats.

Areas like Fishtown, Northern Liberties, Kensington and Frankford experienced up to double-digit growth in value, along with areas of South and West Philly, but the median home price actually fell across the city as the average rose. Some of the most distressed and low-income areas of the city are holding steady or decreasing in value, meaning the gains are concentrated in areas that were already strong, a study by Drexel University's Lindy Institute finds.

One big driver of the spike is the relative lack of supply — the home supply would sell out in about four months at this pace, well short of the accepted healthy pace of around six months, according to the study's author, Kevin Gillen.

One outlier in terms of home value changes is University City, which saw the largest decrease in the city for the first quarter, a 9% drop. As the smallest submarket in the city, it is more subject to such large swings.

"In 2016, University City underwent historic appreciation, so this quarter was just a natural correction," Gillen said.