I'm glad we brought up housing starts. Bear with me for a moment.
In a municipality like CoV, the majority of housing (~90%) is in the form of high-density, multi-unit dwellings that require between 2-4 years of construction from start to finish with the average being roughly 30-36 months for the bulk of new density in a concrete building. If we take 4,200 housing starts between 2011 and 2018, anywhere from 1,200 to roughly 3,500-units would still be underway come 2018 and uninhabitable given construction timelines, particularly how delayed they have been since 2016.
In Langford, though, you have a much higher ratio of single-family-dwellings than you do high-density units (~6 months for construction) and significantly fewer high-density concrete buildings, meaning the woodframe projects that do go up in Langford require less construction time overall (approximately 18 months for a typical 60-100-unit woodframe rental in Langford). Langford also has a higher occupant ratio per dwelling (2.36 vs Victoria's 1.74).
What this boils down to, is if Victoria had a population rise of 9,300 but Langford 8,900 according to BC Stats' estimate and both municipalities had the same housing starts, Langford should, according to its occupant density and faster rate of construction, have grown much faster than the CoV.
Maybe what's happening is you have more pent-up demand for apartment dwellings in Langford (i.e. the kid wants to move out of mom and dad's home on Bear Mountain, but wants to stay on the Westshore) so he rents an apartment in downtown Langford?
garryoak, do you have data for housing completions, not starts for that period?