"A 2.5% replacement rate of housing stock is "steady state". That is, it is indicative of a governmental unit that is neither growing or shrinking."
That inverts to 40 year life expectancy for a housing unit. That seems like a very short time especially in light of the vast amount of resources at are sunk into building a single dwelling.
Part of my difficulty in believing the statistic is that I live in a state that has "old" housing stock.
|Image from eyeonhousing.wordpress|
Another quirk of personal observation is that it is skewed by survivor bias. I see the 1920's vintage Sears kit houses and Gingerbread houses that were advantageously placed and maintained.
Observers do not see the house that were destroyed by severe weather or burned down. We do not see houses that were vacant for two years and destroyed by a leaking roof or a sump pump that ceased working when power to the house was dropped. Those houses were torn down to avoid blighted neighborhoods.
|Construction techniques influence the longevity of the home. Mobile homes are so named because of their tendency to slide downhill if you don't do a good job propping them up with cinder blocks. Picture from HERE|
|Image suggested by GeoW at 24hourcampfire|
Rigorous enforcement of local building codes would go a long way to increasing the longevity of dwellings. There are several places in my house where the stud-wall was doubled-headered on top but the carpenters started/stopped both pieces in the same place rather than over lapping them. I might never have noticed but they are close to doors and windows which are already natural flex points. Stupid, stupid, stupid.
Our house is approaching 40 years of age. There is a symmetry there as our house is approaching its "retirement" age about the same time we retired. We already have a list of upgrades to rejuvenate it for the next 40 years. Windows, doors, drywall, HVAC-wood stove are high on the list.