Sitting in his makeshift office, Birol Ucan has developed an unshakable optimism for addressing the media.

At a time when many Germans seem increasingly hostile to Islam putting down roots in their country, this kind of attitude is probably necessary for the big-bellied spokesman of an obscure Arab organization building a new mosque in the heart of Berlin.

“We thought this room would make a good hairdresser’s,” he says, indicating the waist-high power sockets and the plumbing in the wall beside us. “We don’t have a tenant yet, but it’s cheaper to install fixtures in advance.”

This potential barbershop is one of the shop-fronts being installed on the ground floor of the shiny new Maschari Centre currently being built by the Islamic group al-Habash next to Görlitzer Bahnhof in Berlin’s multicultural Kreuzberg district.

Standing up, Ucan leads me along a glass corridor behind the retail spaces (soon to be a grocery store and a café, he promises) to the lobby, which, with its revolving door, wall-to-wall tiling and reception desk, would suit any mid-range hotel chain.

“Looks nice, doesn’t it?” Ucan remarks, before swinging a flabby arm towards the mosque itself, where a couple of builders look up from their circular saws in a cloud of fine building dust. “Mecca is that way,” he points to a large alcove taking up one corner of the hall. The mosque will host Sunni services, in Turkish and Arabic, despite al-Habash’s unique Arabic roots.

The majority of Muslims in Kreuzberg – and Germany – are Sunni Turks, but al-Habash is an eccentric presence not always welcome all over the Islamic world. Without a militia or a declared enmity to Israel, it is sometimes seen in the West as a peaceful influence in the Lebanon, its home country. But al-Habash is ostracized by many orthodox Muslims, who regard its mixture of Sunni and Shia doctrine and its idiosyncratic interpretation of the Koran as blasphemous.

But none of that can dampen Ucan’s upbeat outlook – he has six more floors to show me. They include various large function rooms – “for funerals or weddings” – and a roof terrace. Like most of the new mosques being built in Germany, this is a multi-functional community centre as much as a house of worship.

Germans have recently started grumbling publicly about the construction of these large, high-profile new mosques all over their country. There has been talk of “creeping Islamization” and the creation of “parallel societies.” The increasingly open insinuation is that shadowy Islamic groups with unaccounted-for wealth are bankrolling gaudy, unnecessary buildings in order to consciously colonize innocent, secular German communities.

Even the multi-functionalism of these buildings is seen as an attempt to draw Muslims away from the influence of western society and it’s often portrayed as nothing less than a conspiracy against the principles of Germany’s liberal democracy.

Ucan is aware of the prejudices and he takes unsolicited efforts to point out that his mosque will strive to lead young Muslims away from radical groups, “who are, unfortunately, also active in Berlin.” Anxiously heading off the expected criticisms, he talks of the German lessons that will be offered here and the architecture that is meant to blend with the Wilhelmine house next door.

This fretful reassurance is surprising, seeing that an unusual tolerance had settled over this structure since its construction began a few years ago. Where mosques in Cologne, Hamburg and in the eastern Berlin suburb of Pankow have provoked citizens’ initiatives and street demonstrations, this one has been allowed to quietly edge towards completion. Any kind of alarmist reaction has been noticeably muted, confined to a few complaints at public meetings.

Perhaps this relative harmony is linked to the new immigrant wealth blossoming in this corner of Kreuzberg – which is frequently called “Little Istanbul” because of its sizable Turkish population. But it’s not more Muslims who are moving here. Richer immigrants speaking English, French and Spanish are sprouting up under the neighbourhood’s café-awnings. Independent art galleries have elbowed room between Turkish bakeries and discount goods stores, and the scent of tapas and sushi now mingles with the smell of döner kebabs.

And so it’s perhaps odd to hear the new arrivals seem more tolerant of the mosque in their midst than some of the long-term Turkish residents.

Kadir Karabulut is a 28-year-old businessman and student who owns a café called Park only a block from the Maschari Centre. Opened this spring, Park has been trying to lure Kreuzberg’s eclectic mix of people with exclusive food, jazz trios and reasonable prices. He has an American girlfriend and is in the middle of an MA thesis in Jewish studies, making him potential poster boy for Kreuzberg’s relative success in integrating its Muslim residents.

And Karabulut has fully adopted two widespread German attitudes regarding integration. First, he has a weird distrust of something called “multicultural romanticism,” meaning he believes that cultural assimilation is necessary for society and that any other opinion is liberal naivety. Secondly, he suggests that religion is inherently an obstacle to integration.

“What bothers me is when Green voters tolerate very reactionary things in the middle of their society – like imams banning girls from sport lessons at school,” Karabulut says in response to questions about the new mosque down the street.

And he’s not the only secular Turk apparently taking a tougher line on the religious Muslisms in their midst than Kreuzberg’s bohemian Germans and other westerners.

Ahmet Iyidirli, a former Social Democratic candidate for the city parliament and a Berliner since 1975, offers a response worthy of Germany’s conservative bourgeoisie when he hears how eagerly Birol Ucan denied al-Habash had any radical religious tendencies.

“So he should be,” he says.