The building, in Great Portland Street, will feature 25 Avid Mojo DX offline suites hooked up to a 24 Terabyte Isis server, plus an archive library and machine room with three ingest stations.
Fifteen additional staff will be hired to run the facility, which already has forward bookings from Talkback Thames, October Films and Shine.
A further three onlines, including a fifth Smoke, and a 3D department are planned for Envy's Rathbone Place head-quarters.
“We are running at maximum offline capacity and have had to turn away£1m of work in the past four months,” said managing director Dave Cadle. “There has always been money to be made in offline if the suites are right for the client.
“It's a rarity if just offline is concluded here,” he added. “For most projects we will perform offline, online and sound dub.”
The launch will bring Envy's operational capacity to 84 suites and more than 100 staff across three buildings.
The company also plans to open a dedicated graphics and finishing facility targeting the commercials market in the next 12 months.
“We're not stopping there,” says Cadle. “We have big plans for next year and beyond, including Envy 4,5 and 6.”