Judging by the pile of wires, lights and other technical debris holding open the front door of the once-plush town house turned a now deserted private bank, however, it's not quite home yet.
As the Edinburgh-based pioneers of site-specific theatre prepare for their latest show, Letters Home, the presence of assorted production managers liaising with their team, designers sprawled on the floor marking out costume patterns, and a technical team holding a quick catch-up meeting in the building's large front room, there's never a dull moment in the company's temporary residence.
A collaboration with Edinburgh International Book Festival, which is similarly in the throes of moving into an array of tents in Charlotte Square Gardens, Letters Home moves into three other addresses in the neighbourhood to present a quartet of dramatised short stories by diverse writers under the guidance of four very different directors.
Two weeks earlier, in a former church hall off Easter Road, Grid Iron's co-artistic director Ben Harrison is overseeing Eve and Cain, the Australian writer Christos Tsiolkas' look at the Bible's most dysfunctional family in an age before letter-writing began.
In the room next door, Joe Douglas, who has just directed Bloody Trams at the Traverse, has gathered his cast around a table to dissect Details, Nigerian writer Chimamanda Ngozi Adichie's email love story.
Once Grid Iron have moved into Charlotte Square, one of the other empty town-houses is co-opted by composer Michael John McCarthy, who has reimagined Jamaican author Kei Miller's study of sexual realisation, England in a Pink Blouse, as an audio installation.
In a fourth house, film-maker Alice Nelson is putting the final touches to her immersive interpretation of Karachi-born Londoner Kamila Shamsie's War Letters.
"It was a very loose brief when the writers were commissioned," explains Grid Iron's chief executive and other co-artistic director, Judith Doherty, who first conceived what became Letters Home before presenting the idea to Book Festival director Nick Barley.
He then selected the writers for the project and commissioned them to write short texts of up to 3,000 words about the idea of writing letters home.
"We'd started thinking about the Square and its history," says Doherty, "and about all the things happening this year in terms of the Homecoming and the Commonwealth Games, and we thought there had to be something there.
"Then we brought in the directors, who aren't all theatre directors, but were people Grid Iron were interested in working in, and who we thought might be good working in this way.
"There was also the thing that no-one really writes letters anymore, and what that means."
Audiences for Letters Home will be split into four groups of 20, who are led around each house, where each piece will be performed four times, to each group.
"We wanted it to be like a box of delights," says Doherty of presenting Letters Home in this way, "or like a treasure-trove, so that you can get all these different perspectives about what home means, or about what it doesn't mean, whether that's in Scotland, in Nigeria or wherever."
The performance will finish up back in Charlotte Square Gardens, where a post-script, penned by Zinnie Harris, will wrap things up.
Harris is also acting as what is described as the show's creative co-ordinator, providing a kind of artistic neighbourhood watch over each mini-production.
"The stories are all so beautifully different," says Doherty, "that I think there will be a need to bring everyone together to share their thoughts, bring things back to Scotland, and maybe get a hug off us before everyone goes back out."
In many respects, Letters Home is a logical step for Grid Iron, whose finest works have often been dramatic reimaginings of literary sources.
These have ranged from performing Angela Carter's The Bloody Chamber in Mary King's Close, to staging Jim Crace's novel, The Devil's Larder, in Debenhams department store, and Barflies, a compendium of Charles Bukowski short stories, in the Barony Bar.
"It was almost an inevitability," says Doherty.
"Literary adaptations have always played quite an important part in the company's history, but we are also part of the Fringe, which is the first time ever something like that has happened.
"Coming into Charlotte Square during the Book Festival is a completely different experience to the Fringe, but being able to bring Grid Iron's Fringe audience into that space was too good an opportunity to miss."