The townhouse market slipped significantly in the first quarter of 2017, but sellers in Park Slope and the Upper West Side had plenty of reasons to smile. Overall, the total townhouse sales volume in the first quarter dropped to $592 million — a year-over-year fall of 31 percent from $857 million, according to a quarterly report from Leslie J. Garfield. The total number of transactions decreased from 101 in 2016 down to 82 this year, […]