If you walk down just about any residential alley in Vancouver, you’re bound to run across one of the city’s thousands of accessory dwelling units (ADUs), known locally as “laneway” or “lane” houses. These little houses range from about 600 square feet to 1,000 square feet. They’re lived in by renters, downsizing homeowners, and relatives of the owners of larger houses they stand next to, including—yes—some grannies. (I personally hate the term “granny flat,” because they’re just as often for young people, and can be thoroughly modern in design.)

Back in 2010, my firm Lanefab designed and built Vancouver’s first laneway house, the Mendoza Lane House, for a wonderful couple who wanted to generate a bit of rental income for retirement. The public interest in that project was phenomenal. The open house garnered a lineup around the block for two days straight. People in Vancouver really, really wanted some new housing options.

Since then, hundreds of detached ADUs have been built every year in Vancouver, and there are now more than 2,000 laneway houses sprinkled across the city. But if you look at almost any other city in North America, the numbers are just a fraction of that. Why?

Many other cities have been timid when it comes to tinkering with the zoning rules for “single-family” neighborhoods, and they’ve crafted ADU policies that simply aren’t scalable. For decades, city councils have used exclusionary zoning to prioritize single-family “character” over everything else (including climate change and affordability), and now we’re in a situation where many of our vibrant cities face chronic housing shortages.

As a first step in reversing this trend, ADUs can be a great, low-impact way to bring new “stealth density” into existing neighborhoods. But it needs to be done in a way that can actually make a dent in the housing crisis.

Based on my experience building 80-plus lane houses, I’ve come to see the following as the key rules for creating an ADU policy that works.

1. Make it citywide and avoid timid pilots

Back in 2008, when Vancouver’s laneway house policy was being debated, there was a suggestion that the program should be run as a pilot project, either with a fixed number of test sites or limited to a specific neighborhood.

The city’s chief planner at the time, Brent Toderian, had a different idea. He argued that the policy should be citywide, with no cap on the total number of units or number of units per block. In 2009, this bold idea was adopted, and in a city with near zero vacant land, more than 65,000 lots instantly became available to support more housing.

Making it a citywide policy did a few things. Not only was the liftoff faster, it was also much more fair. Both the impacts and opportunities of the new policy were distributed across the entire city.

A map of Vancouver’s laneway houses as of 2013, three years after the first projects were completed (City of Vancouver)

Unlike Vancouver’s neighborhood plans, which have selectively densified certain neighborhoods while leaving others largely unchanged, the laneway house policy was an example of geographic equity. The existing baseline for residential development was raised everywhere, from the richest to the poorest neighborhoods, on the busy corridors, and in the quiet backwaters.

Second, from a more self-involved point of view, a citywide policy meant a large enough scale that a practitioner like me could actually grow a business that specialized in delivering these homes. In 2009, in the midst of a global economic recession, Vancouver was able to create an entirely new industry with the stroke of a pen.

2. Make your policy work with every kind of existing home

Whenever I’m contacted by a homeowner outside of Vancouver who wants to build an ADU, I always ask, “Have you talked to a city planner to see if your site is eligible?” We have to ask because so many cities add caveats to their policies that severely limit where the units can be built.

For example, some cities say:

  • you can’t do an ADU if you already have a basement suite
  • you can’t do an ADU if your current home is too large (the existing zoning is maxed)
  • you can’t do an ADU if your current home is too small (smaller than the ADU)
  • you can’t do an ADU if the main house is a rental unit.

And on and on.

Some of the local municipalities outside of Vancouver have added so many burdensome caveats that there are very few lots that qualify. This is great if you don’t like change, but terrible if you want your ADU policy actually to provide housing.

In Vancouver, the lane house policy allowed both an additional dwelling unit and additional square footage. Your ability to build a lane house is almost entirely independent of what’s going on in the front of the lot.

This lane house is only 20 feet tall, but it’s taller than the single-story rancher in front of it. In a city where the ADU has to be “subsidiary,” this home wouldn’t have been allowed. (Lanefab and Colin Perry)

3. Keep the approvals process simple

In Vancouver we have to negotiate the design of each ADU with a city planner. Sometimes this process is easy, and sometimes it is frustrating, but, at the end of the day, it’s a relatively simple process. That’s because:

  • we don’t have to get special approval from the city council
  • we don’t have to do a development permit that’s separate from the building permit
  • we don’t have to solicit feedback from neighbors.

The last point is perhaps the most important. In North America we have a long history of granting neighbors truly extraordinary veto powers when it comes to adding new housing. Going forward, if we want to treat younger generations and renters more fairly, we need to stop trying to litigate housing on a lot-by-lot basis.

Vancouver has thousands of ADUs because the process is relatively simple and predictable.

4. Don’t go crazy with parking requirements (and stop subsidizing garages)

Parking is always going to be a source of drama, but don’t let parking requirements strangle your ADU policy. This is especially true on smaller lots where cars can quickly take up all of the available space.

We argued at length about parking in Vancouver, but in the end, opted to require only one onsite parking space, even where there were three dwellings on one lot (including the main house, basement suite, and laneway house).

Some neighbors will get irate about the new competition for street parking, but here’s the counterpoint: If a neighbor is complaining about street parking, it’s because they’re using their garage or yard for something else; their garage is storage or a shop, their yard is a garden or a patio.

Either way, a lot of single-family-home residents are parking on city property for free while extracting extra value out of their private land. If someone complains about the loss of street parking, ask them if they’re actually using their garage. Don’t let parking complaints kill your housing policy.

One other thing. Let’s stop prioritizing homes for cars over homes for people. Vancouver’s original ADU zoning granted extra “free” square footage for garages for laneway houses. In 2013, the city reversed course and deleted the garage subsidy, allowing more living space instead.

The reason for the change? Most lane-house garages were instantly being transformed into living space. Laneway house tenants, like their neighbors, weren’t using their garages and were parking on the street. So put the required parking space outside, where it will actually be used for parking.

A laneway house originally designed with a garage (behind the row of planters). In 2013, updated bylaws allowed the garage to be converted to a bedroom and home office. (Lanefab and Colin Perry)

5. Don’t force “style matching”

Sometimes we’re asked to build a cute little lane house that matches the cute little house in front. Sometimes we’re asked to build lane houses that are super-modern or industrial. There’s no right answer with regard to style, and in most cases, it’s a mistake for cities to try to dictate what your house looks like.

If we can tolerate (and even celebrate) diverse, fine-grained neighborhoods where every home is unique, then we can also deal with ADUs that don’t match the main house. Besides, half the time, the main house is some godawful pink stucco box. Don’t make us match that.

In conclusion, Vancouver’s ADU policy has been pretty successful. We’ve added thousands of new homes in existing walkable neighborhoods, and we’ve given families lots of options for multi-generational living. The initial complaints have died away and now laneway houses are an accepted and ubiquitous part of the urban landscape.

As for what’s next: we need to start talking about how our pleasant, tree-lined, single-family neighborhoods can evolve into pleasant, tree-lined multifamily neighborhoods. We need to start valuing   affordability and climate-friendliness along with “character” (and actually put that language into our zoning).

If that’s where your city wants to go, a truly scalable ADU policy is a great starting point.