1. how do neighbourhood"s change: aging of physical environment. Style: e. g. architecture trends: social and demographic change in place. Some original inhabitants age in place while others leave: filtering. Private housing markets deliver best locations to wealthy. New generations of wealthy buy desirable units elsewhere. New groups arrive into existing neighbourhood"s (often younger and lower social status, but not always) 3. downgrading (conversion of large housing with one family, to smaller, separate housing to multiple families) . 5. renewal: (public or private) or rehabilitation: (gentrification: housing markets. Access to housing is shaped by the housing market. Cities are comprised of a series of housing sub-markets. Information (we have limited information in housing market) f. g. Movers: younger, renters and those at either end of the income scale. Stayers: middle income, homeowners and older: gatekeepers in the housing market. Social gatekeepers: exchange professionals" who shape residential mobility: real estate agents. Careful observers of change in price and turnover.