Redgate is leasing apartments at its 291-unit Gibson Point development in Revere/Image courtesy of Redgate

Apartment construction activity in Greater Boston hit a decade-long low and asking rents set another record in the first quarter.

Construction activity is gravitating toward transit-oriented locations outside of the urban core in cities such as Brockton, Lynn, Quincy and Worcester, brokerage Colliers noted in a multifamily market report.

The overall pace of construction – with fewer than 15,000 units under way – gives landlords leverage to raise asking rents despite a slight uptick in the vacancy rate to 6 percent.

Average rent per square foot hit $3.12 in the first quarter, up from $3.04 at the end of 2023.

Greater Boston’s large population in the key renting demographic of 20-to-34-year-olds continues to drive demand for rentals, with 6,300 units absorbed in the past 12 months, Colliers research indicates. The vacancy rate now exceeds the 10-year average, however, and many developers of new projects are offering one month of free rent.

Many of the largest recently-completed developments are located outside of the urban core but in close proximity to public transit, including the 201-unit Center & Stone in Quincy Center and 370-unit Alta on the Row in Worcester. The urban core’s share of the overall development pipeline has shrunk to one-fifth of units under construction, after comprising one-third of the metro area’s activity the previous year.

Greater Boston’s high home prices and lingering elevated mortgage rates continue to pose barriers to home ownership, contributing to apartment rent increases, researchers Jeffrey Myers and Kelly Doonan wrote in the report.

The Colliers report comes as data from the city of Boston itself shows multifamily building permits there increased last quarter after falling precipitously for several years.