Construction of a 12,000-square-foot medical marijuana cultivation and dispensing facility has begun at 1050 Elm St. in Bridgewater.

Theory Wellness Inc. hired Waltham-based Vantage Builders Inc. to build out the facility which will house climate-controlled cultivation rooms, drying and processing areas and a retail dispensary.

Designed by Brockton-based BKA Architects, the facility is expected to open in April. The project will include internal construction and significant electrical, plumbing and HVAC work.

In addition to the Bridgewater dispensary, TWI has sought state Department of Health approval to open a retail dispensary in Great Barrington.

In a statement, TWI President Nick Friedman said the Bridgewater facility’s design will ensure a controlled and sanitary cultivation environment.