Mawar:Ideally, grandparents live next door. They have their own space, we have our own. No need to pay parking when visiting. The kids grow up with grandparents around. Grandparents see their grandchildren growing up. But come nightfall, each family say nitey-nite, and retreat behind own door.They are already testing this out in some dual-key ECs.Extracted from iproperty....More families who have relatives living in close proximity to them are becoming more curious about a new breed of adjoining studio apartments termed ‘dual-key’ apartments. In a dual-key home, the studio unit is equipped with a kitchen and bathroom. Its entrance is separate from that of the main unit, both of which open to a shared foyer. For families with elderly parents to take care of, these adjoining units permit a close watch on them while maintaining privacy.