Western cities face multiple interrelated and complex predicaments. Demand for new dwellings has outstripped population growth due to a confluence of socio-demographic trends that contribute to shrinking household sizes: population ageing, high rates of divorce and delayed age of family formation (Wulff, Healy and Reynolds, 2004).In Australia,a quarter of households now contain just one person (ABS, 2012). Similar socio-demographic processes, with associated urban spatial planning implications, have unfurled throughout Europe, the UK and North America (Buzar, Ogden,and Hall, 2005,Re'rat, 2012). Households arekey "agentsof urban transformation"; we need to understand them in order to grapple with contemporary urban problems (Buzar et al., 2005, p.413).The urban implications of shifting "household geometries" (Buzaretal., 2005,p.429)are wide-reaching: (sub)urban sprawl, car dependence, carbon emissions, loss of peri-urban bushland and farmland, rising housing costs, social isolation, socio-economic inequality, and disconnectedness. Urban consolidation appears to offer a solution. High-density, high-rise living has been pitched and implemented as a pathway towards connected, efficient, liveable, compact cities. The need to rethink and replan urban space to accommodate growing populations without endless geographical expansion, is indeed urgent. But existing urban consolidation strategies have been single-mindedly outward looking. They strive for increased density of dwellings; enabling multitudes of small, atomised households to live side by side and on top of one another. But there are other ways of consolidating urban space. Here, we argue the case for looking inward, towards strategies that enable more people to live together within households. Extended family living - in which various configurations of adult children, parents, grandparents, siblings, aunts, uncles and grandchildren reside under one roof - is one option that counters the trend towards shrinking household sizes. This mode of living can make a tangible contribution to the broader projects of urban consolidation, community building and climate change response. We use findings from our ethnographic research with extended family households in Australia to consider two important questions: How might looking inward contribute to environmentally and socially sustainable (consolidated) urban morphologies? What would it take to plan for dwellings that enable more family members to live under one roof, without driving each other crazy?