Allow More New Housing Within the Urban Core
Transit-oriented development (TOD) has become a standard model for development. Wikipedia defines it as:
a type of urban development that maximizes the amount of residential, business and leisure space within walking distance of public transport. It promotes a symbiotic relationship between dense, compact urban form and public transport use. In doing so, TOD aims to increase public transport ridership by reducing the use of private cars and by promoting sustainable urban growth.
A TOD typically includes a central transit stop (such as a train station, or light rail or bus stop) surrounded by a high-density mixed-use area, with lower-density areas spreading out from this center. A TOD is also typically designed to be more walkable than other built-up areas, through using smaller block sizes and reducing the land area dedicated to automobiles.
Transit-oriented development is an important part of reducing greenhouse gas emissions because people who live in denser, more urban areas tend to have a smaller carbon footprint. This is because in cities jobs, housing, and services are closely colocated, so people in cities do not need to travel as far. When they do travel, they have more alternatives to automobile use, and are more likely to use public transit, walking and cycling instead. Also, in cities people tend to have less space, and therefore they have smaller homes, leading to lower emissions from heating and cooling. This is illustrated by a map of US Household Carbon Footprint by zip code included in this paper by Christopher Jones and Daniel M. Kammen that was published in Nature: Spatial Distribution of U.S. Household Carbon Footprints Reveals Suburbanization Undermines Greenhouse Gas Benefits of Urban Population Density:
The City of Shoreline did some calculations as part of their rezoning for future SoundTransit stations, to see what impact the rezoning would have on greenhouse gas emissions. The chart on the right shows the difference it makes to have more housing near the light rail, rather than continuing with single family only zoning and allowing growth to sprawl out.
Seattle adopted transit-oriented development in the early 90's by designating core areas in certain neighborhoods as urban centers or urban villages. Downtown, First Hill, the University District and Northgate were designated regionally and in Seattle's Comprehensive Plan as major urban growth centers. They include high density commercial and residential development and are high priority for service by light rail, and bus rapid transit.
Urban villages are generally zoned neighborhood commercial or low to mid- rise residential; they encourage moderate density and are prioritized for more frequent transit service.
In the context of regional growth management planning, increased growth in urban centers and villages was also a central strategy in the effort to reduce development outside the urban core, in order to preserve forests and farmland. This was part of the King County's response to Washington's passage of the Growth Management Act (GMA). The intention of policymakers was that there would be plenty of housing for everyone, but it would be concentrated in urban areas where people would have reduced travel to jobs, schools, and services while still being able to go outside the city to enjoy the natural bounty that makes the region such a special place to live. Under the GMA, cities are legally required to have a planning process, and to accommodate the expected level of population growth.
Seattle has added on to its urban villages over time, and the population has grown significantly since the urban village concept was initiated. We've grown by 25% just in the last 10 years. To the right is a map of Seattle's urban centers and villages. They make up 18% of the land area that permits residential development in the city, but in 2017 they accounted for 88% of the housing growth.
Still, today compared to most peer cities, Seattle devotes more of its land area to single-family homes. And, compared to most peer cities, rents in Seattle are high: as of October 2021, median rent for a one bedroom apartment is $1726, or now about 2% higher than they were before the pandemic. In Bellevue and Everett, the median three bedroom home rented for $2927 in August of 2021.
Urban Villages impact on Racial Equity
Seattle recently released the Racial Equity Analysis of Seattle 2035 and Urban Village Strategy, which concludes that the Urban Village strategy that governs our current Comprehensive Plan has a disparate impact on Seattle residents, and leads to signifcantly decreased access to housing and economic opportunity for BIPOC communities. The report recommends the following:
Growth strategy: Allow more housing types across the city with equitable access to wealth building and neighborhood opportunities
Affordable housing: Support tools to increase supply of affordable housing with community control and long-term affordability
Displacement: More and stronger anti-displacement policies and tools, including preservation of cultural communities
Inclusive economy: Data-informed tools to promote equitable economic opportunity, e.g., training and hiring preferences
Community engagement: Provide financial/technical support for sustained BIPOC involvement around comp plan update
Recent Zoning Changes
Mandatory Housing Affordability
In spring of 2019, Seattle adopted Mandatory Housing Affordability (MHA) that requires new development in core zones to either include affordable homes, or contribute to a City fund for affordable housing.
Backyard Cottages and Basement Units
In the summer of 2019, Seattle voted to allow detached accessory dwelling units (cottages or DADUs), and attached accessory dwelling units (basement units or AADUs) to provide more housing options. Backyard cottages and basement units can now be added to most lots in single family zoned areas. This allows for more housing in single family zones, but the impact is relatively modest: the Environmental Impact Statement projects 2300 units built over 10 years.
New Comprehensive Plan
Seattle has begun work on a new Comprehensive Plan, which will update Urban Growth Zones, and incorporate changes in zoning and associated changes in services, parks, schools, transit. The City has been directed by Council to include Climate as an element in its Comp Plan, and to include a plan for reducing GHG emissions and vehicle miles travelled, and providing for environmental justice and climate adaptation. One big question is how it will accommodate new growth; will it continue the policy of keeping most of Seattle's residential land zoned as single family or will it allow multi-family buildings? Portland recently completed a rezone which allows 4-unit apartment buildings in all previously single family zones, or up to 6 units if two of them are affordable units.
One big issue from previous years was whether to allow apodments; what is the smallest size we should allow for new apartments? Many people who live alone would rather have a small unit in the city than a larger one that requires long commute times; other people who already live in these neighborhoods are concerned about increased density and parking. One issue that may be more pressing now is the "missing middle" for family sized housing. Now that we have a large number of people who are getting to the age where they want to settle down and raise families, is there going to be a place for them to do that in the city, or will they have to move further towards the outskirts where they can afford more space, but may need to live a more car-dependent lifestyle?
Like Seattle, King County is also updating its Comprehensive Plan, and trying to allocate growth among all of its cities and towns and unincorporated areas.
Seattle and King County should give climate a very high priority when updating their Comprehensive Plans. They need to come up with a plan that will make it easier for us to reduce emissions and housing costs and one that will factor in increased needs for resilience in the face of flooding, wildfires, and climate refugees.
Update: This is an overview of the EIS Scoping, showing the 5 alternatives currently being considered. Here is the full draft Scoping Plan.
Why is urban infill a climate policy?
Many people might agree (or not) with all of this from a planning or a quality of life point of view, but would argue that this is a housing issue, not a climate issue. So, what makes it a climate policy?
People who live in multi-family buildings use less energy to heat and cool their spaces. This is true for two reasons. First, because part of their space is bounded not by the outdoors, but by a neighboring indoor space that is already heated. Second, because people who live in these buildings are likely to have smaller living spaces; and it takes less energy to heat a smaller space. This gives people who live in these buildings a smaller carbon footprint.
People who live in cities are usually closer to all the places they need to go to every day. They are much less likely to be doing a long car commute to a neighboring city, and much more likely to be hopping on the bus or light rail for a short trip, or even biking or walking. If they are driving, they are driving a much shorter distance, on average. This gives people who live in denser areas a smaller carbon footprint.
People who live in the Puget Sound within a Regional Growth Center drive an average 7.1 miles/day; people who live outside drive 17.6 miles/day (Regional Transit Plan p. 66 –local system).
When people live in denser areas, transit becomes much more practical than personal vehicles for getting around. This is true just due to the space taken up by a person in a vehicle, something like 12 feet (the width of a traffic lane) by maybe 30 feet (the distance between the person in one car and person in the car right behind when they are both stopped in traffic). A 2 lane highway can accommodate perhaps as many as 2000-3000 people per hour (assuming they are traveling at 60 mph) , but a rail line can carry as many as five or six times that number (example from Toronto). When people live more closely together, it is cheaper per person to build good transit with fast, reliable, frequent service. In many suburbs, it is difficult to get transit added, because in order to get the same ridership, it must go many more miles, which makes it much more expensive. Riding transit in Seattle, where the light rail and many of the buses are electrified, and the electricity is also low carbon, is a much lower carbon footprint than driving a fossil fuel powered vehicle.
Could we reach our greenhouse gas reduction goals without any urban infill? Clearly it would be much much more expensive, which in turn makes it much less likely.
Allowing More Density: Point & Counterpoint
Will rezoning raise or lower property values?
Home prices in Seattle have seen dramatic increases in the last few decades, as the land within the urban growth boundaries has been built up, and the population continues to grow, increasing competition for a fixed number of available homes. For people that have a substantial proportion of their wealth invested in their house, what effect rezoning would have on their savings is an important question. While that effect is difficult to calculate in advance, here are some ways to think about it.
A rezone would allow more people to live on the same lot, which leaves each person paying less for their share of the land, but the overall price of the land could go up as a result because a group of people can afford to pay more than one person alone. Moreover, with increased density are likely to come increased amenities: stores, coffeeshops, restaurants in the vicinity, that will make the neighborhood more desirable. Some homeowners worry that their land value would go down, because if their house is sharing the neighborhood with apartment buildings, with more people and less parking it will be less desirable.
Will rezoning raise property taxes for current owners of single family houses?
Washington State has a budget-based approach to property tax, which means that each locality figures out how much overall revenue it needs (the levy amount), and then divides that amount amongst property owners based on their accessed value. The levy amount can be increased a maximum of the lessor of 1% per year, or inflation. What this means is that your property tax increases when the rate increases, or when the value of your real estate appreciates relative to the value of other homes in the state, county, or city.
The assessed value has two parts: the value of the land itself, and the value of the improvements (the house and any other buildings on the land). The assessed value is calculated based on the sales values of other comparable properties in the neighborhood. If, for example, you lived in a neighborhood with very low turnover, and then your neighbor sold their house for significantly more, you could see your tax go up the next year in response. We don't know what affect a rezoning would have on sales prices (see the question above), but let's suppose the rezoning was applied uniformly, and the property values changed uniformly across the areas affected. The levy amount would be the same, and your share of it would be the same too, because the value of your property hasn't changed relative to other properties, so it is paying the same share. By contrast, rezoning only one particular neighborhood would change property taxes in that area. If a rezone is applied in Neighborhood A, causing its property values to rise, then Neighborhood A will, over time as accessed values change pay a larger share of the levy, and properties in other neighborhoods would pay a smaller share of the levy.
Will rezoning reduce our urban tree canopy cover?
When houses are removed and new buildings added, it is common for trees to be removed in the process, including our oldest, largest trees. This is a problem for a number of reasons: trees promote liveability, improve our mental health, reduce the heat island effect, sequester carbon, and trees around buildings even provide an insulating effect in colder weather. We already have this problem as small houses are replaced with larger houses, and most of our current tree loss is from our single family zones, but we could expect more loss from increased development after a rezoning if we don't take steps to protect the trees.
There are a number of things we could do. We can give property owners an incentive to preserve their trees by charging them a fee for every tree that is removed. This fee could be on a sliding scale so that larger trees require much larger payments; this only makes sense as they are providing much more value. Additionally, we can require property owners that remove trees to replace them with trees that will grow to a comparable size. Lastly, we could exact a developer fee whose proceeds will go to planting and maintaining trees in the city, possibility including trees in new traffic calming as is already done in some neighborhoods (e.g. Capitol Hill).
Lastly, consider that a ban on development in order to protect trees would have a disproportionately negative effect on forests outside the city. A modest sized apartment building in an urban location can prevent acres of sprawl and tree removal on the outer edge of the city.
We are slowly losing our urban tree cover, and this is really unfortunate for a number of reasons: tree make the city more pleasant and more livable, trees promote better mental health, trees keep us cooler in the summer and warmer in the winter, trees are good for the other plants and animals in the city. But we have long had a tension between density and trees: laws to protect urban forests have been used to block development, but when development does come, it often takes trees with it. However, when development in the urban core is blocked, we get sprawl, and lose many more trees on the outskirts. So how do we have both trees and development while fostering equity?
One proposal I have seen suggested is 3-30-300.
You should be able to see at least 3 mature trees from your home
Every neighborhood should have at least 30% tree cover
Every resident should live within 300 meters of public park or green space
Here are some ideas from a panel discussion in Portland.
We need to create space for people and for trees, and we need to plan that in – design for trees
We need to protect the trees we have, but we also need to plant new trees.
Size of planting/parking strip is important. Wealthier neighborhoods tend to have wider planting strips that can support larger trees, they were designed that way. Planting strip needs to be at least 4 feet wide. 4-5 feet for medium sized tree, 6 feet for large tree, but ideally 10 feet wide.
Cost burden of tree management. Different cities handle trees in planting strip differently, NYC, SF, they manage the trees in the strip, they take of pruning & removal, & liability. Portland does not, so property owners are responsible for that, and fees for taking care of the tree can be $10,000-$15,000 dollars that can come as a sudden expense. People plant smaller trees so they won't have the expense. One proposal is to have the city take over management, but gradually, to reduce the cost burden and require permission for new tree plantings in the strip, register them with the city, and the let the city be responsible for managing the registered trees as they grow. Another approach is for the city to take over by neighborhood, prioritizing disadvantaged neighborhoods that don't have much tree cover.
Historically redlined areas have less tree cover, and therefore more heat
Preserving trees represent a cost for affordable housing projects. Should affordable housing be exempt from tree requirements? For equity, neighborhoods should have trees, but they also need affordable housing not to be priced out. Affordable housing tends to be built in neighborhoods that already have reduced tree cover. You can reduce the fee for tree removal for affordable housing. You can also give a density bonus for preserving trees to give developers an incentive. You can also give credit for planting trees in the neighborhood if the neighborhood has low tree cover.
What department in the city should manage trees? In some cities (including Seattle) there are many different departments managing different aspects of trees. Smaller cities do it better because have smaller staffs and better communication.
Tree protections in missing middle housing at the State level, how can the State help localities pay for tree planning?
Removing setbacks is good for trees because you have more of the yard in one place, more room for larger trees.
Better to plant native trees, because they will require less water, but all trees are good, and some non-native trees may have better shade. But trees that aren't native may die in drought years when they can't be watered.
Rather than just explain tree codes, show pictures of the kind of neighborhoods you are trying to promote.
Require that new parking have a tree canopy.
Articles on Tree Policies:
Equitable Urban Density – How to build without sacrificing trees (David Moehring, Martha Baskin, Charles Kelley)
Trees, Essential Urban Allies Interview with Kathleen Wolf by Martha Baskin, Brady Lawrence and DontClearcut Seattle
Many people will drive, even when they know they’ll be stuck in traffic they will drive. They won't drive if they know they won't have a place to park. That shows you the power of parking. – Brent Toderian
Parking policy also falls under land use. Most American cities have many more parking spaces than they have vehicles, and many would argue that these spaces could be put to better use. Moreover, more parking enables more car use in urban areas, which we are trying to reduce. By using space for parking, instead for buildings, we are putting buildings further apart, which makes neighborhoods less walkable. Urban planners have suggested these three rules for parking:
Stop requiring off-street parking for new developments
Price street parking according to market value, based on the desirability of the space, the time of day, and the number of open spots
Spend that revenue on initiatives to better the surrounding neighborhoods
Since the pandemic, Seattle has vastly decreased the amount it charges for street parking. The maximum fee was $5, and is now $2/hr. Seattle does have a parking tax, which commercial parking lots must pay, but does not tax businesses which provide free parking to their employees or customers, which it could choose to do.
Zoning Reforms Elsewhere
Portland passed a zoning reform that makes 4 and 6-plexes legal in any residential lot in the city. The Urbanist has an article on it.
Oregon has a property tax exemption of up to $300,000 off the assessed value for home owners who rent rooms to low or middle income tenants.
Tacoma is working on a zoning update, named Home In Tacoma. The Urbanist has an article on it: "Single-family areas would be redesignated and rezoned to Low-Scale Residential or Mid-Scale Residential zoning types, which would permit a mix of housing types like duplexes, rowhouses, and apartments."
Minneapolis passed a bill in 2019 allowing duplexes and triplexes on any residential lot. Here's a follow-up article on how it's going from Strong Towns: What if They Passed Zoning Reform and Nobody Came?
From Sightline, a round-up of zoning changes in the nation: Suddenly, Zoning Reforms are Popping Up Everywhere
This year, Washington and Oregon legalized people who aren't related to each other sharing housing in single family zones. See this article from Sightline: Oregon joins Washington to Allow Use of More Empty Bedrooms.
From the LA Times: California enacts two laws to slice through local zoning rules. SB 9 will allow up to four units on certain lots that used to allow only one. There are some limits in historic neighborhoods, and if the land is split into two parcels the owner much stay in one of them. There are some provisions to prevent tenants from being displaced. The state is also making it easier for local jurisdictions to quickly rezone around transit stops. California will spend $22 billion on housing.
Toronto is looking at ending single family zoning. Or in the Toronto Star: Why Toronto’s chief planner wants multi-unit homes in single-family neighbourhoods They are trying:
to boost housing, as he put in, “inside the box...People are probably familiar with monster houses ... maybe it’s six, seven thousand square feet,” he said. “We think, inside that box, you could have three or four units as an alternative ... You would carve it up differently, and actually be able to house a greater diversity of people.”
New Zealand has ended single family zoning, and forces local councils to allow landowners to build up to 3 homes and 3 storeys on most lots, and increased maximum site coverage to 50%.
Density in many urban places is actually going down, because of reduced household sizes and increased living space per person. This image shows density in New York, in 1910 vs 2010.
Other local resources
McKinsey Report: Why does prosperous King County have a homelessness crisis?
Seattle Times: Density is Necessary But Not Sufficient to Ease the Housing Crisis
New York Times: The Climate Impact of Your Neighborhood Mapped
Making Room for Housing Near Transit: Zoning's Promise and Barriers by the Urban Institute
Panel Discussion with Denny Heck, Nov. 2022