With a new Government that is extremely focused on building more homes, it seems a good time to revive our regular update on YIMBY successes around the world, from New Zealand to California.

ADUs

Accessory dwelling units (ADUs) are small, normally single storey, homes built in the back gardens of existing properties. These have long been common in Germany, but exciting reforms brought them to California.

California introduced ADUs in 2016, allowing homeowners to build them on their property. The policy was an instant success. Those who were most impacted, and would normally oppose new development suddenly stood to gain – they could rent out the home for extra income. This has seen California deliver 83,865 homes between 2016 – 2022. Connecticut has also adopted similar rules for ADUs, with a democratic process for any community that wishes to opt out. Most Connecticut towns, 67% of the state, have chosen to allow the state-wide permissions in full or in part.
Elsewhere, Western Australia has removed restrictions on granny flats: they are now permitted up to a total floorspace of 70 square metres.. 

Fourplexes in Toronto

The debate around Canada’s housing crisis has become as fierce as any in California or the UK recently. With an election due next year, both major parties are pitching their policies on building more homes. 

Most recently, Prime Minister Justin Trudeau announced a huge infrastructure fund, available only to provinces who allow ‘flourplexes’ by right. As with lots of housing policy, the devil is in the details. Let’s break it down:

What is a fourplex?

Zoning restrictions in Canada mean that in large areas of many cities, a property owner is only allowed to build one single family home on each plot. A fourplex in the UK might simply be called a small block of flats: four homes in one building. Allowing fourplexes ‘by right’ means altering the zoning code such that, subject to other restrictions, you can build four units where once you were allowed a maximum of one.

So are Canada’s housing problems over?

No. Whilst allowing fourplexes is a great step in the right direction two big issues remain. The first is, because Canada is a federal system, the PM can’t change a state’s zoning laws. In effect this infrastructure fund is a bribe, and some provinces, especially Ontario, aren’t biting.

The other issue is the cap on the number of units per plot is only one part of the puzzle. Toronto, Canada’s largest city, allowed fourplexes by right in 2023, with some controversy, but other rules, like a cap on the ratio of allowed floorspace to the area of the plot (a floor area ratio or ‘FAR’), will limit the actual number of homes that can be delivered.

Single staircase reforms

As Britain ploughs on with its poorly-targeted plan to mandate a second staircase in all new buildings taller than 18m, many housing campaigners in the US are making good progress reversing these requirements because they do almost nothing for safety and are big barriers for affordable homes. The UK Government’s own evidence suggests second staircases generally do nothing to help in the case of a fire, but have huge costs for renters and homeowners by leaving space for fewer, and smaller, flats in tall buildings. The UK’s housing department estimated the rule would cost £2.6 billion for benefits of just £9.1 million.

California, for example, approved single-staircase buildings in 2023 through AB 835, championed by our friends at CA YIMBY. Just this year bills have been introduced in Colorado, Pennsylvania and Virginia to make rules mandating second staircases in multifamily buildings more flexible. 

NZ Upzoning

In Auckland, the Auckland Unitary Plan upzoned much of its low-density neighbourhoods to allow people to upgrade their single-family housing into low-impact small apartment buildings. From 2016 to 2022, the city had 43,500 more new homes started compared to other NZ cities. The impact: rents have grown at a slower pace than wages. 

Nationally, the New Zealand Government zoned for up to 6-story buildings near transport hubs , and their Medium Density Resident Standards permit three-story townhouses in almost every neighbourhood in the five largest cities. These measures happened through cross-party agreement, although the new centre-right government has now promised to let local governments opt out of the mandates for higher density. To permit more homes it  will abolish councils’ ability to set fixed urban-rural boundaries and abolish powers that let councils require balconies or minimum floor area sizes for developments. 

A great YIMBY resource

Is this the sort of stuff you love to read about?

Stephen Hoskins has collected a fantastic set of papers and articles digging into the detailed evidence base underlying many of the policies YIMBYs fight for across the world.

You may also be interested in James Gleeson’s excellent paper The Affordability Impacts of New Housing Supply which sets out in detail why YIMBYs are so sure supply is the key to solving the housing crisis.

Minneapolis also offers insight into the reforms that can stabilise or even bring down rents. They permitted ADUs, reduced parking minimums and allowed triplexes to be built on most streets. Housing permissions quadrupled. Minneapolis rents have remained stable where other cities have seen rents increase by 15% since 2018. 

More US YIMBY wins

President Biden’s 2024 Council of Economic Advisers published an excellent report on the benefits of improving planning rules to allow more densification:

Zoning is one of the most significant regulatory powers of local govern- ment, and research shows reform can unlock economic growth and opportunity (Flint 2022). Zoning reforms that are likely to increase housing supply include allowing more multifamily housing to be built (especially near public transportation hubs), legalizing accessory dwell- ing units (ADUs), and eliminating minimum parking requirements, minimum lot sizes, minimum square feet requirements, and density restrictions. None of these reforms prevent new single-family home construction; rather, the changes prevent municipalities from requiring only single-family homes.

The CEA report also outlines some of the steps various states have taken to boost house building and densification:

  • Buffalo became the first major U.S. city to abolish minimum parking requirements in 2017. Recently, more cities have followed suit, including Anchorage, San Jose, and Gainesville. Other cities, such as San Diego, made incremental steps in the same direction by eliminating parking requirements near public transit
  • Minneapolis banned single-family exclusive zoning in 2018, and Charlotte enacted a similar policy in 2021. At the State level, Oregon, California, and Washington enacted such policies in 2018, 2021, and 2023, respectively.
  • California has enacted multiple policies intended to grow housing supply in recent years. The State has legalized ADUs statewide, allowed duplexes and lot splits in single-family zones, and allowed mixed-income, multifamily housing in all residential areas. At the same time, California has eliminated minimum parking requirements at transit stations statewide. California has also set up a Regional Housing Needs Allocation process, whereby local jurisdictions must produce housing and land use plans to comply with State housing targets.
  • Connecticut has enacted significant policy changes, requiring its cities and towns to “affirmatively further fair housing” in their zoning, promote diverse housing options, legalize ADUs, and cap minimum parking requirements.
  • Montana enacted several changes in 2023 aimed at making housing more affordable and reducing sprawl into rural and agricultural areas. These pro-housing changes include allowing duplexes, ADUs, and apartment-style housing, while also speeding up permitting approvals.
  •  In 2022, Maine passed legislation to allow ADUs and duplexes in residential zones, and legalized quadplexes in “designated growth areas”.
  • In Massachusetts, a program known as MBTA Communities, signed in 2021, requires cities and towns to allow multifamily housing near transit stations, with a minimum density of 15 units per acre . Fairfax County, Virginia, is taking similar steps, such as easing height and density restrictions near transit stations.
  • Vermont legalized duplexes in all residential neighborhoods, as well as triplexes and quadruplexes in all areas served by municipal sewer and water infrastructure in 2023 .

In our next post, we’ll cover the new UK Government’s announcements on housing so far, together with other steps it might take. Look out next week for the proposed revisions to the National Planning Policy Framework.