Much DADU About Nothing


Since the release of the Housing Affordability and Livability Agenda (HALA) Committee recommendations, there has been much speculation on what diversifying the single-family zones means, and if duplexes and triplexes are, ‘too much’.  I don’t think even this nominal increase in density will do much to reduce the ‘economic apartheid‘ (and racial composition) of the status quo, but it’s a step in the right direction for once.

There has been a lot of…shall we say, hyperventilating, about protecting the single-family zones and way too many discussions centering around allowing more detached accessory dwelling units (DADUs) as the ‘compromise‘ to allowing modest duplexes and triplexes. It’s absolutely true that backyard cottages are a better utilization of single-family lots than a detached house. They’re a really interesting typology worth promoting and they could make a property more productive for owners. But it is farcical to argue they’re a practical solution to Seattle’s housing shortage. The reality is that they will, at best, play a very minor role in providing additional housing stock.

Ballard downzoned.
Ballard downzoned.

If DADUs are to play any role, however, they will require a complete removal overly restrictive regulations. This means adopting all of the HALA recommendations for backyard cottages:

  • Removing the parking requirement;
  • Removing the ownership occupancy requirement allowing both units to be rented
  • Allowing both an ADU and a DADU per lot (hey, essentially a triplex!); and
  • Loosening development standards like height limits, setbacks, and maximum square footage.

The HALA report estimates doing all of this will “boost production of ADUs and DADUs to levels in the range of 5% or more of all single family lots within 10 years, which could produce 4,000 or more new homes.”

Disregarding the history from a few years ago where neighborhood groups actually went out of their way to try and prevent Seattle’s DADU regulations from even being adopted, it’s unclear whether or not all the recommendations will be successful. Seattle is presently only averaging about 30 backyard cottages a year–less than a single microhousing project. For a bit of context, we need only turn to Vancouver, BC–the North American holy grail of DADU liberalization. According to Brent Toderian, a renowned Canadian planner, Vancouver, BC is only building a whopping 320 DADUs per year. And that’s in a city replete with higher rents to justify the mortgages.

Assuming Seattle can somehow double Vancouver’s productivity rate, it would still take more than 62 years to produce 40,000 DADUs within the city, as suggested recently by Bill Bradburd, a prominent candidate for Seattle City Council. Exactly how far in the hole Seattle will be on housing at that point, with another sixty years of exclusionary zoning, isn’t clear. But what is clear is that ‘neighborhood activists’ are pushing DADUs as the sole compromise for additional dwelling units in single-family zones, and for the following reasons:

  1. They know it will do very little to address the city’s housing deficit.
  2. It gives the appearance of compromise without really being any kind of compromise at all.
  3. It keeps 49% of the city’s rampant exclusionary zoning perfectly intact while their neighborhoods remain ‘stable’.

Given the contentious history of implementing backyard cottage policies, I find it highly dubious that neighborhood groups won’t fight the HALA DADU recommendations. It’s especially unlikely that all of the committee’s recommendations will be implemented, which doesn’t bode well for higher DADU housing numbers. The overarching question, then, is how much harder will it be to develop anything down the road by keeping half of the city’s land effectively off limits for new housing options over the course of another 60 years? More importantly, how lacking in vision and devoid of creativity is it to suggest a nonsensical, ineffective approach that would affect 25% of all single-family lots for a paltry 40,000 dwelling units (over 63 years!)?

Instead, why not just rezone 7% of all single-family lots to be rebuilt as densely as, say, Vienna’s Margareten? That Viennese district is home to 70,00 residents per square mile. Using the Vienna approach here would add nearly five times as many dwelling units in a significantly smaller time span and area.

Wikimedia Commons by Hjanko.

Confounding, no?

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Mike is a dad, writer, and mass timber architect with a passion for passivhaus buildings, baugruppen, social housing, livable cities, and safe car-free streets. After living in Freiburg, Mike spent 15 years raising his family - nearly car-free, in Fremont. After a brief sojourn to study mass timber buildings in Bayern, he has returned to jumpstart a baugruppe movement and help build a more sustainable, equitable, and livable Seattle. Ohne autos.

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I’m actually a fan of tiny treed frontyards. You can totally have these with two or there story small apt buildings in quiet residential neighborhoods. Berkeley has tons of it (then it got shut down in the 70s).

Like my neighbors have a ADU basically, but it is two stories and has four units. Wouldn’t be legal today due to parking reqs.

So in other words we don’t have to look at the empire capital cities. We can find density with a suburban facade.


There are plenty of areas throughout the country that have very high density (as high as any place in Seattle) but do it without huge buildings. Neighborhoods like this:
Front yard, back yard, trees, nothing as tall as six stories, but the same density (if not higher) than Belltown and South Lake Union. These wouldn’t be legal in Seattle for the reason you mentioned (no parking).


Yea so like now all the construction in Berkeley is large apartment blocks along the corridors. Some even have zero parking due to being adjacent to public transit, but mostly they do have 1:1 space:unit. Anyways it’s fine. Berkeley is also fixing its ADU rules to make it more viable at the moment, which is great, but I bet most units will come from the corridor construction.

The panic Berkeley had in the 70s wasn’t entirely unfounded, they built some ugly cars-in-front apartment buildings in the middle of Craftsman houses. But I do hope we revisit mixing stuff up again. It’s really only racism and such that keeps apartments and SFH separate.


Oh, I don’t know. I don’t think it is racism, as much as fear of ugliness and lack of parking. The problem is that one causes the other. The nicest neighborhoods in Seattle all contain a mix of houses and apartments built before they were banned from some areas and required parking. The cars-in-front apartment buildings are ugly, and most were built because code required parking in some form or another. Now a lot of people just want nothing in their neighborhood, which just increases the cost of rent and causes us to lose a lot of nice big houses — houses that could easily be converted to apartments. In other words, the regulations were designed in part to discourage ugly, but the end result is more ugly (just of a different kind).


best title award of the whole HALA debacle


I think you are underselling ADUs. Saying Vancouver added only a few ADUs last year is like saying that Brooklyn isn’t adding row houses. But row houses in Brooklyn (and ADUs in Vancouver) have played a huge part in increasing density over the years. It is just that now, many of them are already built.

Adding ADUs wouldn’t make much difference if it weren’t for the fact that so much land is zoned as single family. It is about five times the number than multi-family. It it grows by 10%, then it is the same as the other area growing by 50%. The first seems like a small change, the second is dramatic and difficult to sustain.

One of the nice things about ADUs and DADUs is that they retain the existing structure, thus making them more affordable and politically possible. Along with these sorts of changes, the city should allow more full scale house to apartment conversions. Generally speaking, this is how people live now. Families are smaller now. This is why many parts of Seattle have shrunk in the last fifty years, even though more units actually exist. It would be tricky to craft legislation that preserves the old building while allowing it to be converted to an apartment, but not impossible.

But the first step is the changes you mentioned. Those changes would go a long way in increasing density in the city in an affordable and popular manner. Of course there will be people who will oppose the change (just as there will be people who oppose any change) but they are a minority. A very loud minority, but still a minority.

Robert Frances

ADUs (Accessory Dwelling Untis) merely make the properties more expensive and exclusive since the purchase price is that much higher based on teh presumed rent income. A house without an ADU might go for $750,000, but with an ADU it now costs $1,250,000, which means fewer families will be able to quality based on a 20% down payment. Yes, a home buyer can qualify for a higher mortgage with the presumed rent stream from the ADU, but many (most?) families don’t want to deal with a rental unit so it limits supply for a majority of home buyers.

We’re seeing the some exclusionary policies in CA with ADUs, where properties are becoming even more out of reach for middle-income families. If the units were separated as their own purchase units, that would work since their lower cost would be affordable for purchase to many people/families, but coupling them with an existing SFH that is already expensive makes the property unaffordable and exclusive.

Property developers and speculators like ADU legislation since it’s a way to make more money from property, but most people just want a house to call their own without a paternalistic landlord in control of the property. Many of our ancestors left Europe, Asia and Latin/South America to escape feudalism, so it’s curious many so called “progressives” are telling us we need more feudalism (landlords) here in the US. The only people who benefit from feudalism are the landlords and banks. Tenants remain second class residents beholden to a landlord who is always looking for ways to raise the rent, impose more living rules on the tenants, and will use any excuse to evict someone if they can rent the property to someone else for a higher rent.

Besides slavery, there are few worse human relationships ever created than the paternalistic landlord-tenant system. Private landlords should be outlawed altogether, with non-profits the only entities allowed to be landlords, other than maybe a room in a family’s house.


There is no doubt you understand some of the economics of land values (increasing returns from properties can increase the value) but until new policies are passed, one of the few methods we have to combat this is to build enough housing so that people have options.

If we don’t build more housing what realistic options do we have?

You should come by one of our meetups since this is one of the problems we are trying to solve.

Robert Frances

Under the existing model it’s the speculators, developers and landowners who receive most of the profit from land values that were created by current and former residents (reverse socialism). It’s wrong and needs to be addressed with high taxes on all land sales (not involving an owner-occupied home) and high taxes on rent income received by the largest landlords until supply and demand evens out (ie, a vacancy rate between 5% – 10%, so that the market is actually functioning).

When there is a shortage the economic prescription is high taxes on existing suppliers, along with subsidies to new suppliers to help try to balance supply and demand. This is a better option than either (1) rationing, or (2) massive evictions of low-income families in favor of high-income households.

Current land values were created by billions of dollars of government investments (utilities, transit, water, schools, etc.) paid for by former and current residents. Yet the government gives the speculators and developers all of the profits created by these government investments and the human labor that was used to build them. It’s a rigged game. The people build a great area, pay taxes along the way to fund it, but we’re suppose to think it’s okay that it’s only those with access to capital and access to power via rezoning who get the profit from all residents’ hard work and tax burdens?

The government was formed by, and is heavily influenced by, real estate interests, including large financial institutions who fund the industry, so I wouldn’t expect much change. But the best policies would be:

1) At least a 50% tax on all real estate sales that don’t involve an owner-occupied residence. A 75% tax would be better since it would indicate that at least 75% of the land value was created by the former and current residents and taxpayers, but the speculators and developers are still allowed a 25% share of the land value profits. The tax can be phased in over 4-5 years so the impact is lessened on current speculators.

2) No interest expense and phony depreciation deductions allowed on any real estate investments other than an owner-occupied personal residence. Cap the mortgage deduction at 75% of the medium home price, with a phase-out up to 100% of medium home price. Wealthier homebuyers don’t need the mortgage subsidy. This allows a housing subsidy to middle and lower-income families, but would end the billions of dollars of tax subsidies currently given to wealthy speculators that distort housing markets.

3) A 10-20% tax on all rental income – less costs of repair and maintenance – whenever the vacancy rate is less than 10%. Use the tax proceeds to eliminate regressive sales taxes, pay off regressive bonds that transfer millions of dollars of interest payments from taxpayers to wealthy bondholders, and build housing that can’t be owned by speculators (ie, limited-equity ownership with resale restrictions to owner-occupiers only).


The HALA committee recommends significant up zones in the urban centers and urban villages, and also recommends expanding their footprints. Those areas are designed to be walkable and close to great transit service, and they will have the capacity to accommodate expected population increases over the next 20 years. Not sure why it’s also necessary to turn SF neighborhoods into MF.


Would love if you came by a meetup again. I think we fundamentally disagree about whether duplexes and triplexes would change the nature of SF zones. Most of us don’t believe that duplexes and triplexes would make them anything like MF zones.


Thanks for the invite, Owen. Will try to make one next month. Always happy to discuss my opinions. It may come down to what each of us mean by the “nature” of SF neighborhoods.