Great photos. These aerial shots really highlight Calgary's lack of historic "workers" or middle-class housing that is dominant in the core of almost every older city on the continent. A large, low/middle wage industrial workforce necessitated very different housing forms than were ever built in Calgary and at a much higher density - the typical worker didn't have the income to have anything close a single-family plot, and transportation networks pre-automobile required walking or transit distances to employment, forcing density. As a product of their age and workforce, it's no suprise that cities like New York, Montreal, Toronto, even port cities like Vancouver and Portland all have so much more (formerly) working class housing close to the core in the form of walkups, townhouses, rowhouses, small apartments, lot-line-to-lot-line developments etc.
With a limited historic working class population, plus the addition of disproportionately higher-income white collar population in the age of the automobile and suburban sprawl it really shows - particularly on the stark transitions between our higher density areas immediately dropping off to wealthy SFH. Neat to see the economic history of development so clearly visible from the air.