Photo: Ruth Hartnup/Flickr
Half of single-family homes in Vancouver are currently at risk of being torn down, with one-quarter of detached homes at risk of being torn down between now and 2030, according to a new forecasting tool. The new tool, created by a pair of Vancouver researchers, is using a residence’s value and the value of the overall property to predict how likely it is that the home will be demolished in the future.
According to a University of British Columbia (UBC) news release on Tuesday, the tool known as the “teardown index,” suggests that the lower the value of the residence compared to the overall property’s worth (its relative building value or RBV), the more likely it is that the house will be torn down and replaced by a new one.
The teardown index was created by UBC professor of architecture Joseph Dahmen and MountainMath Software founder Jens von Bergmann, in an effort to discover what factors influence the likelihood that a single-family home will be torn down and the environmental impacts of the new development being built in its place.
“Increasingly for single-family homes the actual value of the house has very little to do with the overall purchase price. And so these two are intermittently related as we found out when we actually studied what makes a tear down a tear down,” von Bergmann tells BuzzBuzzNews.
To create the teardown index, the researchers used municipal data and BC assessment records on Vancouver single-family homes purchased and sold between 2005 and 2015. With the data, they compared land value, building value and property sizes with factors including if the property was torn down a couple of years before or after being bought or sold.
With Vancouver’s recent rise in home values, the tool predicts one-quarter of detached homes in Vancouver could be torn down between now and 2030. Right now, half of single-family homes have RBVs below 7.5 per cent, which is a far reach from the aim for a new development’s RBV between 60 and 70 per cent.
The researchers discovered that when the RBV of homes drops below 10 per cent, there’s a significant rise in the number of teardowns. “It’s a little bit more than one in four that get torn down at 10 per cent relative building value,” says Dahmen.
For new single-family developments, Dahmen says the average RBV is around 38 per cent, which may sound high but is not ideal. “It’s quite a bit lower than what we hoped to see, which is about two-thirds of the value of the property tied up in the building and one third in the land,” he says.
If a quarter of Vancouver homes are torn down by 2030 as the tool predicts, the researchers want to use their data to assess the possible environmental impacts of the new homes being built. With building operations becoming more efficient, Dahmen says “as we get closer to zero emission buildings, the embodied impacts of the materials themselves will become a much greater share of the overall impacts.” He says RBVs could improve by focusing on the materials and energy efficiency which in turn would help break Vancouver’s cycle of demolition and construction.
Their complete analysis can be found at mountainmath.ca/teardowns.