Chris Walter, @ChrisWPhoto, talked with Matt Hutchins about the significance of Accessory Dwelling Units (ADUs).

At CAST architecture, we have been focused on ADUs for more than a decade. They're fun to design, perfectly fit a niche for new housing in established neighborhoods, and provide many benefits for owners and residents.

https://www.youtube.com/watch?v=PJaLht9v5Yw

CAST’s Cedar Cottage is a City of Seattle Pre-approved DADU. Our vision is to adapt the high-design cottage, simplify it, and make it accessible.

See more at www.castcottages.com

“Part of the reason we love backyard cottages is just the opportunity. If you have a home with a possibility for a second house – it could be whatever you want it to be – a studio, a place for grandma, a rental, and having that flexibility is huge. We have people who have it as an Airbnb, or a long-term rental, as a place for their kids and then their retirement home. This flexibility is fantastic. It opens up so many opportunities in this great city.”         -- Matt Hutchins, AIA, Certified Passive House Designer

Backyard cottages = Flexibility and Opportunity

Published at Seattle’s Daily Journal of Commerce https://www.djc.com/news/ae/12162400.html

Give Middle Housing a shot!

Matt Hutchins’ comprehensive discussion, at Medium, of the Washington state Model Code for Middle Housing and how we can have it produce more housing in line with HB1110.

In HB 1110, the State Legislature read the will of the people and demanded that we tackle the housing crisis more proactively by allowing Middle Housing in most cities and towns. Washington State Department of Commerce has created a basic zoning template that supersedes local code if town planners balk at updating their own code to comply. The draft version of that Middle Housing Model Code is out for comment (comment here by December 6th!). I have analyzed the real world implications of how it would regulate new housing and how we can tweak it to better support the creation of townhouses, flats, and infill development.

Here are my recommendations:

1. Allow Middle Housing to be larger than single family houses: more lot coverage, smaller setbacks, and make them taller.

Diagram of current allowable single-family building sizes in 6 cities to illustrate that the Model Code’s Floor Area Ratio system is actually more restrictive.

It seems like an obvious point that the bulk of a building or buildings for up to 2, 4 or 6 households might be larger than one with just a single household, but a close look at some of the cities governed by this new legislation reveals that the draft code is MORE restrictive than current codes. It would effectively be a downzone in structure size in order to house more people. That isn’t a good trade, and for all the proof that Middle Housing has wide ranging benefits, we should have a code that supports it.

Middle housing is not just a bridge between the densities of single-family neighborhoods and denser areas, it is also a incremental increase in size between those building types.

2. Measure lot coverage, not FAR

There is a policy conversation about two methods for measuring building size: 1) lot coverage X height vs. 2) lot size X Floor Area Ratio. The draft code uses FAR for Tier 1 and 2 cities (the larger cities and the municipalities around them), and Lot Coverage for Tier 3 cities (smaller cities).

In the six Tier 1/Tier 2 cities I picked to analyze, five use lot coverage not FAR. The model code should follow suite. It is easy to implement, understand and compare apples to apples to existing codes.

Diagram of small cities buildable footprint illustrates how extra flexibility in lot coverage will translate to new housing for those communities.

Meanwhile Tier 3 cities, the code uses lot coverage to provide flexibility for how to develop successful infill housing, because lot coverage isn’t the critical threshold, the market is. I think this part of the Model Code will be actually be good for many smaller jurisdictions that are struggling with housing cost and access.

3. Set thresholds by looking at what can be feasibly built, not what might be politically expedient.

Illustration of all the new building types and whether they would be viable under the draft Model Code for typical lot sizes.

There is often a disconnect between how planners see development standards and how developers implement them. But ground truthing the code, when it is a draft, to understand the inevitable determinative impacts on the housing types that will get built, is the key to making the good development we want to see also the easiest to build.

Using a typical 5000 sf parcel zoned under the new code for 4 units, applying the FAR, we can build 4000sf. It becomes immediately apparent that many of the housing types we’re hoping for will never materialize and other types are going to yield less that then maximum number of units. Of the six types, I would expect the only feasible project is three townhomes. It is unlikely we’d generate very many 1000sf townhouses, 1200 sf triplex units or courtyard apartment buildings under the added cost of the IBC compliance.

The FAR needs to be up between 1 and 1.2 before we’d see the fourth townhome, or an apartment building.

4. Lean into making the most efficient and affordable housing form (small apartment buildings) the default infill Middle Housing type.

Our Spokane Six on the left works today, but wouldn’t be viable under the draft Model Code. This illustration shows that it would need to be 21% smaller.

Small apartment buildings have significant headwinds when it comes to financing, construction and operation. They also are the greenest, most efficient, context friendly and often least expensive forms of housing. They are also the best for preserving usable open space and landscape for large trees. They are the lowest common denominator building block for tackling the housing crisis. If the code works for those, then the other forms, like ownership townhouses, will work too.

When we tested our recent Spokane Grand sixplex, using the new Model Code, we discovered that we’d have to reduce the size by 21%, loose one of the porches, and downgrade the units from family friendly two bedrooms to one bedrooms. The pro forma for the development fell apart. If it can’t work in Spokane, with low land cost, reasonable construction cost, steadily climbing rents, there is very little chance these buildings would be viable in Puget Sound or other Tier 1 and 2 cities.

Without zoning incentives to build apartments, the market will continue to underproduce less expensive rental housing, even if we see some new ownership townhomes.

5. Reduce parking minimums.

Parking is always the cart that drives the horse. We have a housing problem not a parking problem.

So much has already be said and written about the high price of parking mandates, so I’m going to appeal to pure geometry.

On residential lots, designing for parking is step 1, before you even start to conceive of a building. For a sixplex on an alley, where parking is required, one space per unit arranged along the alley would require a lot width 56' feet minimum, which is wider than most urban lots. In order to provide the parking, much of the back yard is overtaken with pavement, more than 1/3rd of the site, lessening the quality of life for residents, creating stormwater issues and additional costs.

Without an alley, it is always worse; more than half of our typical lot is parking or driveway.

6. Regulating aesthetics on small neighborhood buildings is unnecessary micromanagement.

Strike this section. Or don’t. It is really so milquetoast that compliance isn’t an issue, but there will be lots of overlap/conflict with local codes that do regulate these simple aesthetics. Most townhouses are less that 20 feet wide — does a building’s design need to change every time there is a door? It is so fussy. In the interest of less bureaucracy, we should stamp out regulatory creep preemptively.

A Model Code that works.

The State’s Model Code is an opportunity to create a baseline for Middle Housing but it has to work. And this draft code would be so much more effective if it wasn’t second guessing its own mandate.

A final Model Code based on incremental increases of size over current single family structures, lot coverage not FAR, without parking minimums and design prescriptions, which allows builders the flexibility the make the homes people need, is the right direction forward for a statewide standard.

Cross-Laminated Timber Berm House in Washington's Methow Valley

The Berm House is a private residence that doubles as the common house and gathering space for a 19 house mixed-income community in Washington’s Methow Valley. The house is set into the landscape, with a panoramic view of the farmland down valley, but hidden from the road by a berm that ramps up onto and across the roof. 

The south-facing building orientation optimizes winter solar exposure coupled with large overhangs to protect from snowfall and the intense summer sun. The home is post and beam structure with a cross-laminated timber (CLT) roof prefabricated in northeastern Washington. The design incorporates Passive House principles including managing seasonal heat gain from solar exposure, advanced air sealing, and mechanical ventilation. Thermal bridges are minimized by wrapping the house in continuous external insulation, including structural EPS under the foundation, isolating the home from outdoor temperature swings. The earthen roof adds thermal mass, wildfire protection, and a promontory to take in the down valley vista.

The great room portion of the house was designed for friends and neighbors to gather, share meals, and be a social center for the community. Off the great room, a five-foot wide hall leads to three guest suites and the primary suite. The uncomplicated and efficient floor plan shows a clear division between the private and public spaces. The mechanical room, pantry, storage, guest bath, and laundry spaces are arranged along the berm side of the house’s section.

The material palette is predominately warm woods. The CLT ceiling and glulam posts and beams were manufactured nearby, and a coffee table and kitchen bar were crafted locally from a fir tree felled on the property. The exterior employs the Japanese shou sugi ban preservation technique. The boulders throughout the site and as part of the berm were pulled from the site and placed by the owner. 

Team
Owner: Lee Whittaker
Methow Housing Trust
Architect: CAST architecture
Contractor: Methow Valley Builders 
CLT: Vaagen Timbers
Concrete subcontractor: JR’s Five Star Concrete
Geotechnical Engineering: GeoEngineers

See more here.

STATE MODEL CODE FOR MIDDLE HOUSING IS MISSING ENOUGH HOUSING

BY MATT HUTCHINS (GUEST CONTRIBUTOR)

See full article and graphics here: https://www.theurbanist.org/2023/07/10/state-model-code-for-middle-housing-is-missing-enough-housing/

Commerce recently had a consultant create a form-based code, but the draft fails to advance housing abundance.

Now that Washington State’s Middle Housing bill (HB1110) has been signed into law, the next question is what implementation will look like — what kind of housing and where. The Department of Commerce has published a request for consultants to draft a model code that 1) will help jurisdictions write their own compliant middle housing code or 2) will supersede local zoning if they fail to implement their own in advance of the deadline (six months after their comprehensive planning update).

While we don’t know what cities and towns are thinking, we do have a picture of how Commerce is approaching the middle housing code. Last fall, Commerce hired a consultant to “inform about and assist local governments with middle housing policies, regulations, and programs.” 

In May, a focus group of planners, developers, and architects previewed a draft ‘Toolkit’ that illustrates four strategies that local governments could overlay on their residential zoning to allow new denser housing types within existing detached single family neighborhoods. The foundation of this toolkit is a form-based code meant to create ‘objective’ standards for middle housing that can be applied widely.

The issue is that the toolkit, rather than solving for affordability, feasibility, and the lowest carbon footprint, is primarily focused on crafting development guidelines that will keep new infill development the size of average houses and thus minimize the outcry from vocal neighbors. While this might be an easier to swallow approach for Washington cities and towns, it doesn’t scale up to address the deeper issues that HB 1110 was passed to address: the massive shortfall of new places for people to live. 

While Commerce’s original intent was to come up with instructive materials broadly applicable to most local governments, the effort lags behind what more progressive jurisdictions are already doing. But when we dig into the details, the toolkit suggests real reductions in development capacity: smaller footprints, bigger setbacks, and lower roof heights than are currently allowed in many Puget Sound cities. At its very worst, it will give slow-growth municipalities the option to select a new zoning overlay that is more prescriptive and restrictive, thus spoiling any chance that any new middle housing will be built.

Let’s go through the proposed new toolkit and look at some of the underlying flaws. 

• They state, “This toolkit does not provide standards for buildings taller than three stories.” For three of the four overlays in the Toolkit, buildings are conceived as two and a half stories with a height bonus for hip and gable roofs –  less that most of Washington cities’ least dense residential zones today. Rather than proposing an actual incremental increase, it ignores the status quo as a starting point. If you want a single pitch ‘shed’ roof, the 22-foot height limit is actually less than what we allow for a backyard cottage in Seattle today.

• Parking is mandated throughout the toolkit, a reversal for many jurisdictions that are moving away from required off street parking. Indeed one of the strengths of HB 1110 is releasing parking restrictions for new housing.

• Most overlay zones top out at four units per parcel, equivalent to Seattle’s second least dense zone, Residential Small Lot. Much of the ‘middle’ housing that is missing is between a house-sized triplex and the ‘5 over 1’ medium-sized apartment building. While this toolkit focuses on redundant standards for housing types we already allow, like townhouses and triplexes, it is silent on helping planners visualize appropriately-scaled urban buildings that might have between six to twenty units.

• Townhomes today, for better or worse, are the least expensive middle housing alternative available in the market, and the toolkit hamstrings their development with provisions that limit the number per building and the building length. The most successful rowhouse style homes on corner lots wouldn’t comply.

• The toolkit increases barriers for sites with multiple buildings on a single site, which would render many currently popular types of middle housing, such as detached townhouses, cottage clusters in Residential Small Lot zoning, and arguably even detached accessory dwelling units nearly impossible to build on compact urban lots.  

• The toolkit does not provide flexibility for sites that might want to preserve existing housing and build more. It assumes parcels are cleared rather than provide provisions for new buildings in the backyard, lot splitting, or additions that add units.

• While much of today’s urban design discourse is centered around neighborhoods where goods and services are accessible within a 15-minute walk or roll, the toolkit doesn’t have any provisions for mixed uses like daycares, commercial suites or corner stores.

• Finally, as one gets into the details of each overlay, it is chock full of reductions: larger setbacks, less lot coverage, less height, larger minimum lot areas, prescriptive design standards – each taking a bite out of the viability of future housing. When we compared a fourplex we’re currently designing in Spokane against the toolkit, we’d need to reduce the footprint by 32%, lose the front and back porches, and downgrade the 2-bedroom units to 1-bedrooms.  

• Unlocking the residential potential of urban land is critical if we’re going to provide the more than 1.1 million homes Washington State projects we’ll need over the next 20 years, and that means reintroducing multi-family housing types that exclusionary zoning has regulated out of existence.
  
  With this upcoming model code, we can take a good hard look at how new infill development is built, but we first have to move past the idea that middle housing is house-sized buildings carved into more apartments, or cottage clusters. Overall, the toolkit’s conceptual limitations and prescriptive ‘objective standards’ don’t reflect the real conditions of Washington neighborhoods.  

  A more serious effort would worry less about what neighbors might think and center our goals of housing abundance and climate action leading with middle housing types that work all the way up to four- and five-story mid-sized buildings in keeping with the best practices of urban planning around the world. Washington needs a flexible model code that supports the big picture goals of abundant housing.

An array of CAST’s detached accessory dwelling units (DADUs)

Statewide efforts to boost housing options make headway

This past legislative session, several bills made it through both houses and each will have long term benefits for the production of urban infill housing types such as cottages, ADUs, and small stacked apartment buildings.

HB 1337

The passing of HB 1337 expands housing options by easing barriers to the construction and use of ADUs.

·        legalizes two ADUs per lot in any configuration of attached/detached

·        legalizes an ADU on any lot size that’s legal for a house

·        legalizes ADU size up to at least 1,000 SF 

·        legalizes ADU height up to 24 feet

·        ends requirement for owner to live on site

·        caps impact fees at 50% of those charged on houses

·        lifts parking mandates within 1/2-mile or 15 minutes from transit stop

·        prohibits design standards or other restrictions more stringent than what applies to the main house 

·        legalizes ADUs to abutting property lines on alleys

·        legalizes ADUs in existing structures that violate current rules for setbacks or lot coverage

·        prohibits requirements for public right of way improvements

·        legalizes the sale of ADUs as condominiums

HB 1110

The Middle Housing Bill will mandate that medium and large cities create development standards for their lowest density zones to accommodate more housing.  For Seattle, it means:

·        Up to 4 units on any parcel not previously limited by an HOA or PUD.

·        Up to 6 units on parcels that are within ½ mile (a 10 minute walk) of frequent or fixed transit

·        Up to 6 units on any parcel if 2 are designated as affordable. 

The form that these new housing types will be open ended, but the Department of Commerce is busy developing a model code for cities to use as a starting point.  The deadline for cities to comply is 6 months after their next comprehensive plan cycle (for Seattle that is mid 2025). 

Spokane Four

As one of the region's leading voices for abundant and affordable housing choices, we have been advocating for backyard cottages—accessory dwelling units (ADUs)—since Seattle first considered them citywide in 2009.

More efficient land use is critical to address our housing crisis, climate change, and persistent inequities in access to housing opportunities. Modest infill houses like ADUs are a key strategy to empower citizens to provide new housing, build generational wealth, and leverage taxpayers’ investment in infrastructure, transit, schools, and parks. 

Seattle Architect CAST partners with The BLOCK Project

CAST has partnered with The BLOCK Project which builds fully equipped, healthy homes for people experiencing homelessness.  

We are excited to have just permitted our second BLOCK Project home!

BLOCK Homes are permitted and placed in homeowners' backyards throughout Seattle. This model gives residents a place to call home and our communities an opportunity to make a real difference in supporting our unhoused neighbors and addressing the issue of homelessness together.

Their mission: To inspire deliberate relationship building and community engagement as a pathway to ending homelessness.

www.the-block-project.org
@facinghomelessness

Seattle Architect CAST designs affordable housing in the Methow Valley

Winthrop, Washington

ON THE BOARDS — The Housing Authority of Okanogan County’s new Wildrose Apartments will provide 22 new affordable housing units targeted at families earning 30% of Area Median Income. Homes will be a mix of one-, two-, and three-bedroom apartments, accommodating families, seniors, and young adults. A major design goal of the project is to achieve a high-level of integration between the apartments and the surrounding neighborhood of affordable single-family homes being simultaneously developed by the Methow Housing Trust.

The apartments are distributed into three 2-story structures surrounding two sides of a large commons that serves both communities. Both upper and lower units provide outdoor space facing the park, energizing the open space with many sources of activity around its perimeter. The footprint and envelope of each building is kept simple to reduce cost; secondary porches and balconies add visual interest while providing solar shading and weather protection.

Housing Authority of Okanogan County’s mission:
Assisting residents of Okanogan County to acquire and retain affordable housing while strengthening our communities by removing barriers, empowering dignity, and building trust.
www.okanoganhousing.org

See more: www.castarchitecture.com/wildrose-apartments

Reposted by permission of Sightline Institute

Author: Matt Hutchins (@HutchinsMatt)

A Seattle street showing the inclusion of more middle housing. Rendering by Matt Hutchins, used with permission.

matt hutchins, AIA, PHCD, INVITES CITIES AND TOWNS TO ZONE AND DESIGN FOR THE FUTURES THEY WANT

TAKEAWAYS

• Seattle has concentrated several decades of population growth within narrow corridors of the city, disproportionately affecting poor and BIPOC communities while failing to ask nearby detached-house areas to evolve and grow as well.

• Cities and towns with rising housing costs can address home shortages and inequities by opening up their zoning to new design options, as proposed by a middle housing bill that Washington state leaders are currently considering.

• One such design: the Seattle Six, an attractive, economical, adaptable design that enhances neighborhood vibrancy and prioritizes quality of life, environmental responsibility, and anti-displacement. Cities and towns elsewhere can imitate or design their own such solutions.
  

If you want a healthy garden, you don’t blast just a couple plants with the hose; you water everything slowly so the roots can soak it up. Same with a city or town: sprinkle some housing everywhere, and you’ll get healthier neighborhoods.

Under Seattle’s Urban Village Growth Strategy the city has funneled 25 years of growth into tightly designated areas without asking adjacent detached-house areas to evolve as well. Along with America’s decades of racist redlining, car-centric design, and the primacy of detached-house building, this kind of strategy has limited what our cities can be. It has sent home prices skyrocketing, deepened racial inequities, and failed to address climate change in how we build our communities. Certain “gentle density” solutions like backyard cottages and townhomes have expanded housing options in tight markets, but for metro areas, the need is greater than these alone can address.

Fortunately, Washington legislators are currently considering a powerful “missing middle” housing bill that would open up a host of modest-sized housing options for people across the state while delivering numerous other benefits for communities. They are reworking zoning rules to empower us to build the future we want. And they are making it possible for architects like me to creatively contribute to the suite of design solutions that can help address the multiple challenges our cities and towns face.

INTRODUCING THE “SEATTLE SIX”

As an architect, I see how zoning regulations, good and bad, directly shape the design of buildings. Right now, there is a once in a generation opportunity to conceptualize the next basic building blocks of our towns and cities, starting from a set of key guiding values:

• Healthier neighborhoods focused on quality of life

• Adaptable site design and flexible home configurations

• Deep green construction and inhabitation over a building’s life cycle

• Centering anti-displacement

• New possibilities for ownership, subsidized rentals, and more affordable housing

And while this design was developed specifically for Seattle’s typical lots and market, the values driving it are ones many Washington communities share. This is an invitation—and opportunity—for Washingtonians everywhere to imagine what could be possible in their own neighborhoods.

The “Seattle Six” is a three-story apartment building with six to ten households that fits on a range of typical residential lots. It has a compact form that is optimal for deep green building and observes the same height limits as Seattle’s Neighborhood Residential, Residential Small Lot, and Low-Rise 1 zones. In transit-rich areas, it can accommodate additional stories and units. With a floor area ratio (FAR) between 1.5 and 2.0, the Six is still small enough to bypass thresholds that trigger Seattle’s onerous Design Review. And finally, it proposes a clear direction for the urban design of streets and blocks that works in the short, medium, and long terms, aesthetically and economically.

HEALTHIER NEIGHBORHOODS FOCUSED ON QUALITY OF LIFE

The Seattle Six delivers a range of benefits for neighborhood vibrancy, connection, and attractiveness for residents both in and near Sixes. First, it energizes the sidewalk without overwhelming the street. By reducing the front setback to 12 feet but allowing stoops, covered porches, and balconies in an 8-foot-deep buffer, more residents have access to open space and a connection to life on the street. It replaces the idea of forced façade modulation with the option to embellish and individualize the building, while providing an amenity without complicating the basic structure. Overall, it is similar in height to currently allowed designs and recalls the classic small apartment buildings constructed in the decades before zoning strictures banned them from much of the city.

At the block level, over time, the Six establishes a land use pattern with well-defined urban edges and an interior courtyard in the backyards protected from noise, pollution, and street intrusions. It better preserves existing trees and makes room for new ones, a big advantage over typical oneplexes and townhomes, for instance, which slice up open space into narrow throughways or make backyards the only available land for new housing.

The Seattle Six, a modest-sized apartment building designed specifically for lower-density neighborhoods. Rendering by Matt Hutchins, used with permission.

Speaking of backyards, the Six prioritizes access to larger rear yard open space, ample daylight, and options for big terraces for each flat. Units face both the street and the backyard, where kids can play or gardens can flourish, an improvement over another building across a narrow side yard. Residents cycling in will appreciate the design’s easy bike access, accommodating lockable individual bike storage at the ground floor and again in each unit.

Comparison between current and potential zoning envelopes for urban infill development. Illustration by Matt Hutchins, used with permission.

What’s more, on an everyday quality-of-life basis for people living in or near a Seattle Six, the benefits multiply. Because denser housing types bring in new families, one block with ten Seattle Sixes would have enough families with kids under five to justify a small daycare. Five more similar blocks would have enough customers for a successful café. Ten more, and you have a walkable/rollable neighborhood with local jobs, rapid transit, retail, services, and restaurants. At corners, the ground floor units could be live/work, corner stores, daycares, or cafes. Because it fits well with detached house neighborhoods, the Seattle Six can locate away from busy arterial streets and near to places like parks, schools, and libraries, bringing more vitality to every block.

How a block can grow. Top left: typical block of detached houses. Top right: typical townhouse development that would result in tree loss and inefficient use of open space. Bottom left: Ten Seattle Sixes sprinkled through the block. Bottom right: a full block of Seattle Sixes, showing how exchanging narrow side setbacks for larger back yards creates far more useable open space and more room for big trees. Illustrations by Matt Hutchins, used with permission.

In most cases, building a Seattle Six would require demolition of an older structure, just as a big new oneplex does today. This is exactly why Seattle should also allow alternative infill options like backyard ADUs and small-plexes that can coexist with older structures that remain in fine shape.

ADAPTABLE SITE DESIGN AND HOME CONFIGURATIONS

The Seattle Six supports a range of household sizes, multi-generational living, and moving within the building as life situations change. One can downsize and “age in place” or upsize as their family grows without having to give up the community of neighbors they’ve gotten to know.

Ground floor and typical upper floor plan showing flexible range of unit types (click on images to enlarge). Illustrations by Matt Hutchins, used with permission.

Even on lots smaller than the 50’x100’ Seattle standard, the design is flexible enough to offer a variety of unit sizes. Floors can be a mix of family-sized one- and two-bedrooms; they can combine into one large multigenerational floor and later split into a principal flat and mother-in-law; or they can comprise a sprinkling of studios. A single central stair optimizes each floor for living space rather than the dark double-loaded corridors typical of larger apartment buildings. The version shown below is built on a concrete slab at grade level, but a partly below-grade floor of garden units would be practical depending on the topography.

The Seattle Six fits into existing neighborhoods and connects more people to life on the street. Illustration by Matt Hutchins, used with permission.

The ground floor features accessible units via ramp, as well as a flexible studio. Residents can use it for a variety of purposes: for residents with temporary disabilities, housing a caretaker, or a short-term guest suite. Alternatively, it could be a common room, hosting things like teen game nights or get-togethers in a co-housing community.

DEEP GREEN CONSTRUCTION AND INHABITATION OVER A BUILDING’S LIFE CYCLE 

Buildings are a major source of climate emissions, but they don’t have to be. They can incorporate deep green construction that reduces a building’s embodied and operational carbon.

To this end, the Seattle Six is conceived using Passive House principles in its design. The Six’s simple, compact form, continuous insulation to keep interiors comfortable at a consistent temperature, and shared party walls reduce energy loss, paying back residents with a lifetime of low heating and cooling demand. Paired with rooftop photovoltaic panels, the Seattle Six can be net zero energy.

Diagram of the Seattle Six’s green building features: Passive House, Net Zero, and Dowel Laminated Mass Timber. Illustration by Matt Hutchins, used with permission.

As for materials, the Six’s structure is designed with a dowel-laminated timber structure, which sequesters carbon and minimizes the need for concrete or steel, resulting in a low embodied carbon construction. The mass timber party walls and stair core satisfy the fire resistance rating. And bonus: it can be remanufactured for use in a future project as part of a more circular economy.

The Six also accounts for its region’s natural environment. Its green roof and on-site storm water management limits runoff from the site. And as wildfire smoke becomes more commonplace, the Six’s heating recovery ventilation system not only saves energy but filters pollutants to supply fresh air throughout the building.

COUNTERING DISPLACEMENT

The goal of Seattle’s Urban Village growth strategy was to concentrate new housing around commercial centers and serve them with an expanded transit network. But the strategy’s zoning changes disproportionately landed on poor or BIPOC neighborhoods, such as the Rainier Valley. The consequence has often been a cycle of speculation, displacement, and gentrification at the expense of people who’ve built their lives there.

Having a small apartment building that can plug in anywhere, starting in areas the city characterizes as having “low displacement risk” (i.e., most residents have the means to stay in their homes or find other housing nearby), would reduce the pressure on housing in other, less expensive areas. In a city like Seattle that’s adding lots of jobs, building lots of homes is essential—and the Six is a template for every neighborhood to do its part.

Allowing six or more households to divvy up the cost of Seattle’s pricey land lowers housing costs, too. Efficient, modern buildings like the Six would offer a mid-sized and mid-priced option between detached houses or townhouses on the one hand and large apartment buildings on the other. Indeed, Sightline recently analyzed possible development scenarios under Portland’s new zoning code. It found that new triplexes and fourplexes weren’t quite financially viable there in most cases, but that sixplexes in Seattle’s more expensive market might be.

In other words, the Seattle Six fights displacement in exactly the same way it fights segregation: it creates a new, cheaper way for people to live near jobs, parks, schools, and good public transit while reducing development pressure on other vulnerable neighborhoods.

NEW POSSIBILITIES FOR OWNERSHIP, SUBSIDIZED RENTALS, AND MORE AFFORDABLE HOUSING

We’ve underproduced housing for nearly a generation, putting even the most modest starter home beyond the reach of most Washingtonians. In just a decade, the state’s median home price has increased by 237%. Rents are on a similar trajectory, rising 183% for a two-bedroom apartment over the same period.

Whatever form new development takes, we’ll also need creative forms of ownership: co-ops, urban co-housing, and condos, for example. One interesting idea well suited for Seattle is the Polykatoikia, where landowners who are cash-poor but land-rich negotiate with a developer to swap a new apartment building on their land in exchange for a flat or flats in that new building. It is an excellent way for local landowners to maintain and grow generational wealth, stay in their neighborhoods, and create new homes in the process.

The “polykatoikia” idea, or housing swap, by which a homeowner can support new housing, maintain ownership, and resist gentrification. Illustration by Matt Hutchins, used with permission.

To the south, Portland’s Residential Infill Project allows developers to build extra units in exchange for affordable housing. The Seattle Six framework could easily support more households, too: either with an extra floor or a smaller height limit bonus to add a level of garden suites. Seattle’s Mandatory Housing Affordability performance option won’t help private developers create on-site affordable units given the small scale, but perhaps some of the MHA payments taken in by the Office of Housing could be deployed to finance small apartments, similar to how the Equitable Development Initiative has been supporting anti-displacement efforts.

BUILDING THE TOMORROW WE WANT, TODAY

It is a watershed moment for Washington: an opportunity in our housing policy to address climate change and racial inequities while building the homes we need and communities we want. The Seattle Six is just one model of how that might look. It’s also an invitation, as state leaders consider critical middle housing legislation, for communities across the state to boldly envision the future they want and build it into reality.

Matt Hutchins is a principal at CAST architecture, specializing in creative urban infill, affordable housing, green building, and shaping land use policy. He serves on the Seattle Planning Commission and as the Director of Public Policy for AIA Seattle. He is a Certified Passive House Designer. Find him on Twitter at @HutchinsMatt.

Matt Hutchins was recently featured on the Compounding Change podcast. This show is about how small actions create big results, hosted by Seattle Realtor, Gunnar Conley. They talk of good planning, complete neighborhoods, density, and the built-in affordability of accessory dwelling units. It’s part of Matt’s mission to make cities, neighborhoods, and homes agents to fight climate change. Go to: https://podcasts.apple.com/us/podcast/compounding-change/id1513993853?i=1000518698366

COMPOUNDING CHANGE PODCAST FEATURES MATT HUTCHINS