The monolithic, sand-coloured silhouette of the Al-Islah Mosque is unmistakeable against the background of high-dense public housing in Punggol New Town, Singapore. The 3700 sqm Mosque is planned to serve the local Muslim community with a peak capacity of 4500. We seek the notion of an 'Open Mosque’. As an integral part of the local community that is largely non-Muslim, the new mosque aspires to be a model of openness, reflective of contemporary Islamic aspirations in Singapore. The idea of openness extended beyond the formal manifestation of visual porosity, accessibility and climatic openness, to the embracing of different needs within the Muslim community. At the greater community level, in addressing the role of the mosque in promoting religious understanding. This ambition for the openness posed much challenges in view of the tight site and its proximity to the neighbouring flats. Physical porosity allows visual connection to the neighbourhood and extends the its spatial field beyond its boundary but poses the issues of sanctity and threshold expected of a mosque. Climatically, poriosity offers much benefit of ventilation and daylighting but presents challenges of protection from the monsoon rain. The mosque is simultaneously modern and traditional in its formal aspirations. A voluminous, open prayer hall occupies the ground floor, shielded by an overhanging canopy that occupies the entire buildable footprint, like a big roof eave. Atop this canopy is the elevated landscape tererace where 3 distinct volumes housing the Main Prayer block, Islamic Learning Centre and Administration block, sit. Sacred architecture should always serve its primary function of worship. They serve the community and sometimes become places of refuge but we like to envision a future where they can bridge differences in an increasing fragmented world.