These are heady times for the Montreal film scene — both for local filmmakers and for those who pay the rent toiling on Hollywood shoots. But the boom has come with growing pains.

After years of flying well below the radar internationally, made-in-Montreal pics are all of a sudden generating mucho buzz around the globe, a fact highlighted by two consecutive Oscar nominations in the foreign-language film category. At the same time, foreign shooting is also booming chez nous with three straight record-breaking years for Hollywood filming in town.

There is a new generation of Montreal helmers who are making pics that have much more appeal for industryites, festival programmers and auds all around the world.

Things are just as rosy for Hollywood filming in Montreal. After a disastrous 2008, foreign filming in Quebec rose to $166 million in 2009, surged to $214 million in 2010 and hit the $235 million mark in 2011. It is expected to pass $235 million this year thanks to pricey Hollywood pics like “Smurfs 2,” “White House Down” and “RED 2.”

But with the filming surge comes challenges.

“We need to have the capacity to properly service the boom,” says Brian Baker, who runs the Quebec office of the Directors Guild of Canada.

One step in that direction: The owners of Mel’s have bought an empty lot next to Mel’s 2 and plan to build four more large stages. Building may begin this fall. Provincial funding agency Sodec suggests time has come to do a feasibility study about building another studio to compete with Mel’s.

Hollywood filming was going gangbusters in Montreal in the late ’90s and first few years of this century but it dipped big time around 2003 when the Canadian dollar started rising in comparison to the U.S. buck. During that earlier boom, American producers were nabbing considerable savings here simply as a result of the exchange rate.

Now the city’s film milieu is ramping up to deal with the return of the Americans.

“We’re having to revamp,” Baker says. “We had lost some of our infrastructure. So our challenge is getting it back to service the boom. Our skilled labor dipped.”

Orgs like the Directors Guild of Canada are aware of shortage and looking at ways to increase the number of local skilled technicians. Meanwhile productions have been importing technicians from other Canadian cities when there are several big shoots at the same time.

Back in the ’90s, local English-language production was also doing great in Montreal and that also dropped off around the same time Hollywood filming went missing. But the difference is that the English production has yet to bounce back.

Montreal’s French-language film producers face a different challenge. The province’s art films win prizes and play the fest circuit across the globe “and this gives us an enormous amount of recognition internationally,” says Quebec film commissioner Hans Fraikin. “But the next step is figuring out how to commercialize these films internationally.”

A key factor in the return of Hollywood to Quebec is the province’s generous tax-credit program that gives foreign producers a 25 percent credit on all money spent in Quebec and another 20 percent on labor expenses for all visual-effects work done in the province.

One problem remains the scarcity of major American TV series lensing in Montreal. This is partly the result of a more limited English-language acting pool compared to either Toronto or Vancouver.

“That means that for major roles, where you don’t want to travel people in, it’s hard to get the scope of age groups and accents,” says Muse Entertainment topper Michael Prupas.

But the city makes up for the lack of series with the real pricey studio pics such as “White House Down” this summer and “Mirror Mirror” last year.