Singapore's unofficial official design style is modern, born of the clean, earnest, dutiful modernism from the heyday of Western corporate headquarters (1960s-1980s). Modern design has offered Singapore a way to brand an identity for the sake of locals and foreigners alike. In the nation's early years, the fast rise of American-style office buildings gave Singapore a prosperous and familiar look that appealed to Western investors wary of Asian inscrutability. Now that Singapore really is prosperous, with a 2004 growth rate of 8.4 percent and an Asian standard of living second only to Japan's, modernism provides a nondenominational building style - a vocabulary unattached to any Asian region, race, or religion. One could argue that modernism maintains prosperity by keeping the ethno-religious peace. It may not always be pretty, but it never takes sides by looking too Chinese or Malay, too Buddhist or Muslim.
Its local architect, Tan Kok Hiang, a principal of Forum Architects, has explained that contemporary design is more strategic than traditional Islamic architecture, at least in this place, at this moment. First of all, the Middle Eastern mosque archetype is not only foreign to Singapore, but it is also imposing, even off-putting: The Malays are not Arab. On the other hand, a more modest mosque in the Malay vernacular might repel ethnically Chinese converts to Islam.
Interested? Architecture Week has a more detailed feature on the Assyafaah mosque. Next step is to visit it.