Nevill Holt opera in Leicestershire has submitted plans to build a permanent, 400-seat opera house on its stable block.
The company has been staging summer opera since 2013.
It expands the countryhouse opera scene which consists of Glyndebourne, Garsington, Longborough, two rival Grange Park companies and a couple more, all of them functioning without state subsidy.
The Nevill Holt estate is owned by David Ross, who funds the opera company. Its manager is Rosenna East and its chief aim is to foster emerging talent.