Stanton Andrews Architects has received planning consent for a £1m extension to the Grand event venue at Clitheroe.
The extension will create a second performance space, a green room and additional function rooms as well as improving circulation to the main stage.
The additional floor area is approximately 3,350 sq ft.
No fixed start date has been set, but it is expected construction will not start until after summer 2013.
Stanton Andrews anticipate the extension will complete no sooner than early 2015.
The Lancaster Foundation, a Clitheroe-based charitable organisation, purchased the building in 2005 before undertaking a redevelopment of the premises.
The building was converted by Preston-based Conlon Construction, but a decision is yet to be made on a contractor or preferred procurement route for the new extension.
The Grand event venue hosts various performing arts-based activities and projects.