Dan Bertolet writes for the Sightline Institute on a certain kind of density infill. We call these “basement suites”, “granny flats” and “laneway houses”.
ADUs are relatively modest apartments or cottages integrated into single-family properties, and they come in two flavors: physically attached to the main house (AADU), or detached in a structure separate from the single-family house on the same lot (DADU). Most fall in the moderate affordability range—$1,200 to $1,800 per month for a one-bedroom unit in Seattle—and offer a housing option in single-family neighborhoods for residents who cannot afford a single-family house.
Known as “granny flats” for a reason, ADUs work well for multigenerational families. And they are particularly well-suited for young children, because they tend to be relatively large (at least for a rental), provide direct access to outdoor yards, and are often located in neighborhoods well served with schools and parks.
And why does Vancouver have lots of these type of dwellings? What does the rest of Cascadia need to do?
Myriad regulatory barriers currently litter the law books of Cascadian cities, clogging the ADU pipeline. Vancouver’s success in building more than 26,000 ADUs has been all about undoing those restrictions. Starting in the late 1980s, the city legalized thousands of existing, but illegal, ADUs. Over time, it eliminated the most counterproductive barriers. Vancouver, unlike many Cascadian cities:
- does not require an off-street parking spot for each ADU
- does not require the owner to live on site
- allows single-family lots to host both an AADU and a DADU
- awards additional occupancy limits for each dwelling on a property, and
- provides great latitude to property owners in terms of size, height, and placement of each ADU.
Another relevant question might be, why is Vancouver so much less affordable than these other two Cascadian cities, despite providing so many more ADUs?
That’s an easy question to answer – supply and demand (both real and perceived).
Frank – Chinese money. They want to live in Canada versus US and they only want 2 cities in Canada and we are one of them.
Yes, its funny how reluctant some people are to state the very obvious difference between Vancouver and the two US cities. When you offer low scrutiny of the source of money flowing in and don’t ask too many questions, you get “rewarded” by being priced out of your city.
Well what do you mean by “affordable housing?” Are we talking about about affordable city living or affordable home ownership?
ADUs only increase rental supply. They do not result in a subdivided lot and do not increase the amount of real estate for purchase. They may result in more affordable city living as they increase the supply of rental units, which increases vacancy and could slow the rise of rental prices.
I’m unsure what affect ADUs have on the price of real estate. It seems like a toss up to me. The potential total rental income one could gain from a detached single family home is greater with an ADU than without, so arguably, if the potential to build an ADU is factored into the price of a home, the regulatory allowance of ADUs could result in an increase in the price of single family homes in general.
If one desired to decrease the cost of home ownership, a better policy could be to eliminate single family home zoning and ADUs in favour of more flexible “low density” zoning where one could divide the property into smaller units.
A shorter answer could be that whatever impact ADUs have on the affordability of purchasing real estate is dominated by more significant other factors.
Might have just found the answer. “Single” family houses could indeed be more expensive because they are really not single family lots anymore. When people can build and get revenue from more units units on the property, it really should not be that surprising that they are more expensive than cities where this is not allowed.
One would need to compare growth rates in order to answer that question definitively.
Interesting.
What would we do without them?