"In the UK our work is considered quirky," he says. "In North America we are considered very avant-garde, in France we are considered North American with culture. In Germany they see our stuff and say, 'Finally! Not Regietheater!'. He gives a very Gallic shrug, as if to imply that culture critics are all daft anyway. "We don't really care what they call us. It's the audience that matters."
Barbe is a Quebecois opera designer and one half of Montreal's Barbe & Doucet production duo; the other half is his husband, the French director Renaud Doucet. Since the pair met at L'Opera de Montreal in 2000 they have not accepted any work apart. They come as a double act or nothing, a joint brand in which design and dramaturgy are inextricable. It is an artistic vision as well as a life decision: if they were going to make their relationship last in an industry that involves long periods away from home, they decided they would simply have to work together or not at all.
"Any couple needs a project, whether it is a kid or an industry," says Barbe. "We don't have kids. This is our project."
The result is the work of Barbe & Doucet has a trademark aesthetic as well as conceptual thrust - so much so they also always work with the same lighting designer, Guy Simard. "If we speak about blue to Guy, he knows the kind of blue we mean," says Doucet. "He is a key part of our house style."
So what is that style? Anyone who saw the bling-drenched, gilt-framed, frilly-costumed Manon they created for Scottish Opera in 2009 will get the picture. By their own description their productions are 'fun', 'accessible' and - riskiest of adjectives - 'popular'.
"Yes!", says Doucet, leaning across the table intently. "We want our audiences to have a good time. If somebody takes the effort to buy tickets, to dress up, to pay for the nanny, they do not do that to be miserable. They do that because they want to have a good night. So the minimum we can do is to put ourselves in their seat and think, 'Would I enjoy this?'"
To research what works by way of popular entertainment, the couple often go to see shows on Broadway or the West End. In Glasgow they tried a pantomime (Aladdin at the King's) "to see what speaks to audiences here." Inordinate amounts of sexual innuendo, it turns out? "Well sure, but it is important to know what is the popular medium."
Barbe and Doucet are back in Glasgow for Scottish Opera's new production of Donizetti's opera buffa Don Pasquale and, unusually for an industry that tends to guard its creative concepts under wraps until opening night, they have made no secret of what the look and style of the production will be.
The setting is 1960s Rome. Cantankerous old Don Pasquale owns a seedy hotel that is managed by his wayward nephew, Enrico. Norina is Enrico's mouthy girlfriend, Maletesto is Pasquale's allergy doctor, the chorus is a stream of travellers checking in and out of the pensione.
"We wanted to find a time in history when Norina would have stood up for herself," Doucet explains. "In the 1960s women were taking charge. The clash of generations is also crucial in this opera - the fact Pasquale is out of touch with the younger characters and that they play around and take advantage of him. The dramatic shift in attitudes and behaviours that happened in the 1960s seemed to fit.
"Plus we wanted to keep it in Rome because it is raining in Scotland and people need to see some sun!"
For the most part their production sounds like a fairly straightforward updating - nothing too conceptual, and certainly not Regietheater. But Barbe and Doucet have added one significant new dimension to the plot. Their Don Pasquale is obsessed with cats.
"We thought of the idea because cats are everywhere you look in Rome," says Doucet. "It is very normal to see older people petting them and feeding them. The sad irony in our story is that Pasquale is in love with cats and yet also extremely allergic to them."
It is a poignancy intended to reveal a more tender side to a character who is often portrayed as the classic buffoon. Renaud and Doucet are adamant that Pasquale is not simply the stock Pantalone figure of commedia dell'arte - indeed that stereotypes do not apply to any of the opera's characters. Because although this opera is above a comedy, they underline their intention to bring out its inherent social commentary.
"We know some elderly people in France who live with two cats and two dogs and prefer the company of animals than of human beings," says Doucet. "Animals do not judge. They are generous. There is a good reason why Pasquale, who knows he is out of touch with the young people around him, is drawn to them."
Barbe sees the opera as a chance to examine how contemporary Western societies treat the elderly. "The global population is getting older and we do not know what to do about it. Having lived through the death of my parents and seen how elderly people can be treated in retirement houses - well, we wanted to make it clear Pasquale is not simply a bad or mean person. The younger generation laugh at him, but they are not malicious either. Sometimes they realise they go to far. Nothing is black and white in this opera."
A serious message, then, beneath the fun and Roman sun. How does the slice of social commentary fit with the Barbe & Doucet house style? When I ask what criteria lies behind the productions they take on, they tellingly respond, in unison, that any opera they work on "has to be a really good theatre play".
Underneath the aesthetics they are actually text junkies, they tell me: they like nothing better than working with a libretto that could stand up without any music at all. "When the play is good we can have fun," Doucet says. "When the play is weak we can only put the cream on top of the cake. If the cake is not good it might look pretty, but it is not gonna be tasty. Don Pasquale? Very tasty."
Don Pasquale is at the Theatre Royal, Glasgow, January 24-February 1, and the Festival Theatre, Edinburgh, February 18-22.