Elementary school enrolment in Vancouver is plunging because there isn't enough affordable, family-friendly housing in the city, a new report says.

Enrolment in city elementary schools is down by more than 3,500 students, a drop of more than 13 per cent since 2004, says a report by BTAworks, a new urban research arm of Bing Thom Architects.

"A big factor is the fact that there is unaffordable family housing in the City of Vancouver," said Andrew Yan, a BTA works researcher and urban planner who wrote the report to be released today. "There's a serious affordability issue here in Vancouver."

Yan notes that the school population is going down despite the city's six-per-cent population growth.

Yan said an increase in private school enrolment only accounted for a fraction of the enrolment decrease in public schools.

He studied enrolment data from the Ministry of Education as part of its ongoing series focusing on Vancouver neighbourhoods.

Schools on the city's northeast side faced the largest losses while enrolment on the west side remained stable, and in some cases increased.

"We're building all these condo towers with housing that really isn't supporting families," said Yan, noting they're leaving for suburbs such as Surrey or heading to Toronto or to U.S. cities.

Yan said Vancouver "runs the risk of becoming increasingly family unfriendly."

Yan hopes his report will start a discussion on the city's sustainability.

jkeating@theprovince.com