As office and lab developments creep closer to older residential neighborhoods in South Boston, a proposed life science is shrinking in height and size to appease opponents.

In March, Boston-based Anchor Line Partners and Alexandria Real Estate Equities proposed the 371,300-square-foot office and lab building at 99 A St.

An updated version presented this week to the Boston Planning and Development Agency and a community meeting reduces the building size to 303,637 square feet, while trimming its height from 133 to 106 feet. The new plans increase parking from 76 to 162 spaces in a below-grade garage.

In public comment letters submitted earlier this year, South Boston residents objected to the size and height of the building, and said it will detract from the residential character of the neighborhood.

“People moved here because it is a family neighborhood with welcoming restaurants, shops, and parks. It is a community where the voters care about the quality of life. The people who will own and work in this BioScience building do not care about or vote in this community,” one resident of the Port 45 luxury condos at 45 West Third St. wrote to the Boston Planning and Development Agency.

The Alexandria-Anchor Line development team is among a group of high-profile investors planning to build class A office and lab space near the Gillette headquarters on parcels formerly occupied by parking or older commercial and industrial buildings.