Asking rents for industrial properties in Greater Boston hit record highs in the second quarter after a 27.5 percent increase in the past 12 months.

CBRE said the average triple-net rent now stands at $13.43 per square foot, an all-time record, while vacancies hit a historic low of 1.3 percent.

Developers are responding to the steady demand with 4.7 million square feet of speculative construction under way in the region, including 670,000 square feet that broke ground in the second quarter. The Davis Cos. of Boston broke ground on a 214,400-square-foot speculative development on Upton Drive in Wilmington, while National Development began construction of a 305,500-square-foot spec development at 201 Lowell St. in Wilmington.

The Metro North market led the region with nearly 400,000 square feet of positive absorption during the quarter.

The region’s diverse tenant landscape – including robotics, life science and wholesalers – recorded 1.8 million square feet of leasing during the quarter, CBRE reports. Major transactions included 151,000 square feet by Cold Storage Solutions at 97 Wood St. in Middleborough, 141,000 square feet by battery manufacturer Ambri in Miflord and a 135,077-square-foot renewal and expansion by Pfizer at 44 Lowell Junction Road in Andover.

Turmoil in public markets and rising interest rates are reducing funding to life science companies, creating headwinds on future demand, the report said, but financially stable life science continue to seek space for expansion.