Jersey War Tunnels museum is hoping to host more private functions and corporate events.
Organisers have been given planning permission to build a new cafe, which they hope will attract people from Jersey and abroad.
They have also applied for permission to extend the opening time.
The Jersey War Tunnels, a museum of the German Occupation in World War II, currently has permission to open until 2230 GMT.
Paul Simmons from Jersey War Tunnels, said: "We would hope it would be an additional revenue stream but our core business will always be the tunnel experience.
"But if there is any other business to spin off from that then we would be interested in capitalising on that."