Friends of the Globe secretary Keith Scott said the fundraising milestone was reached after the tireless targeting of trusts by fundraising committee chairwoman Rosemary Beresford over the past 18 months.
The $143,000 from the Lottery Grants Board helped build early momentum and the goal was reached with a ''thrilling'' $50,000 grant from Transpower on Tuesday.
The money would guarantee the future of the London St theatre, after years of doubt.
Planned repairs would include making the theatre's octagonal roof weathertight, Mr Scott said.
''When it rains, it drips on the stage and on the audience.''
As a precaution, the theatre's 77 seats were protected from the rain by a tarpaulin.
Repairs would also include seismic strengthening, more fireproofing, the replacement of rotting cladding, repaving the path from the fire exit, improving access for the disabled, interior painting and new carpet.
The builders were expected to start any day and would be on site for about six months.
The theatre would be closed while the work was undertaken and he expected it would reopen to the public next year.
The first production was guaranteed to be ''something flashy'', Mr Scott said.
Since the theatre opened in 1961, more than 400 productions had been presented and many people given the chance to get theatre production experience.
''That has probably been why we have been able to get that $500,000 because we are this non-profit organisation that not only provides entertainment but provides an opportunity for people to get involved.''
Despite the theatre's temporary closure, its 2015 season had begun in the Athenaeum Theatre in the lower Octagon.
Fundraising would continue, with the focus shifting to renovations of the Heritage NZ category one house attached to the theatre.
The 1867 Italianate house was built by architect and Dunedin mayor William Mason.
''We are desperately trying to save it,'' Mr Scott said.
People can find ways to make donations at www.globetheatre.org.nz/donating.php.
shawn.mcavinue@odt.co.nz
