"Because when you've got a piece like War Horse and a historical event that's of such significance then you really want that piece in the building for that," she says. "It felt important to bring it back but then when they actually came in and I saw one of the technical sessions, I felt really emotional."
During the past decade, it has also enjoyed a two-year stint on Broadway and in 2011 was turned into a Hollywood film by Steven Spielberg. It's now about to embark upon another world tour, which includes Auckland in June.
War Horse is based on an existing text - like the National's other recent popular shows including a beguiling version of Mark Haddon's novel The Curious Incident of the Dog in the Nighttime and Richard Bean's subversive comedy One Man, Two Guvnors which cleverly updated Italian playwright Carlo Goldoni's 1743 play The Servant of Two Masters.
"That was important with both War Horse and Curious Incident, as there was already an audience familiar with the books," says Burger, who insists the phenomenal success of all three shows could not have been predicted. "The thing that unifies all three of them is that you certainly would never have known when they were first programmed that they were going to be breakout hits that they've since become."
Burger attributes much of that success to British Government subsidies, which has allowed the theatre to spend time and resources on research and development.
"The precious and fabulous thing about that is that it has provided us with a very private space where directors, writers and designers can try things out as it's absolutely crucial that people can try things and fail and then try again," she says, stressing how much War Horse has changed since its formative days.
"When we were rehearsing it in the studio, actors were running around with cardboard boxes on their heads," she recalls. "The early previews were also much darker but by the time we came to the second run at the National in 2008, some of the puppets had turned into characters."
Worked by either a single operator - as seen with the hilarious goose or in the case of Joey and his fellow horses, by a team of three - it is War Horse's extraordinarily lifelike puppets that have captured the hearts and minds of audiences, almost upstaging their human counterparts.
"The puppets are amazing, as are the puppeteers," says Burger. "We've had generations of them now and a lot of work still goes into the technical skills needed for making and mounting them, as you want the play to feel fresh every time somebody sees it."
Launching National Theatre Live with Helen Mirren's Phedre in 2009, the National also revolutionised how we watch theatre, broadcasting live – or in New Zealand's case, slightly delayed – performances into cinemas all over Britain and the world. Burger says the cinema screenings have enabled the National to reach new audiences it wouldn't have been able to access before but more importantly, it's also influenced the National's live output.
"Having seen that there is such an appetite for our work around the country as well as the world, it's given us a lot of impetus and confidence to tour as well," she says. "It's very much a reinforcing thing because people can come and see us in Auckland in June, but in reality, we only get to go to New Zealand every five years or so. But, in between times, there's still a connection there through NT Live and that's what we want. We want to feel that we are there for everyone."
Lowdown
What: War Horse
Where & when: The Civic, Friday, June 21 – Sunday, July 7
