As part of its plan to increase housing options in the city and to find solutions to solve missing middle housing, the City of Seattle has recently changed regulations around accessory dwelling units. Commonly referred to as a mother-in-law apartment,  an accessory dwelling unit is a smaller residential unit tied to a single family house that comes in both an attached and detached typology, known as ADU and DADU respectively. Picture a finished basement with its own kitchen and entry from the rear or a separate cottage on the same property.

In previous years, the Seattle Municipal Code enforced by the Seattle Department of Construction & Inspections (SDCI), required two significant items that dramatically reduced the feasibility of ADU or DADU projects. One, each ADU required onsite parking be provided, and two, the property owner would have been required to physically reside in one of the units on the site for at least 6 months out of the year.  In addition the units were limited to 800 square feet. The former requirement ate up valuable footprint space making a lot of Seattle sites, especially those with environmentally critical areas like slopes and wetlands, too small to add an additional structure, and the latter often priced out any developer beyond a homeowner interested in taking on construction risk to invest in their property. In 2019, the City of Seattle removed these requirements and began allowing two ADU’s per lot. Since then Seattle has seen an increase in this type of project entering the permitting process.

While this change definitely encouraged the development market to explore another avenue to create housing, the ADU/DADU cluster has very little difference to a project type we at b9 architects are already familiar with; namely, the duplex and Single Family house, or even a three unit townhouse development. Where the two differ most is in zoning and size.

As a part of the change to the municipal code that allowed this type of project to flourish, the City has made this three unit typology admissible in all Neighborhood Residential zones (formerly Single family residential), a zone that until this change could only allow one house with one accessory dwelling unit. With this change, a significant portion of land in the City of Seattle has been unlocked as developable. The trade off is in size. While Seattle’s multi-family zones would allow three townhouses of any size (so long as they meet FAR guidelines) this typology limits an ADU or DADU to no more than 1,000 sq ft each, with allowances for storage and garages that exceed that amount. 

The 335 DADU is a small backyard residential unit completed in 2017. This would have been the only typology allowed in Single Family zones.

The 335 DADU is a small backyard residential unit completed in 2017. This would have been the only typology allowed in Single Family zones.

If you look at our 2018 study Urban +, you’ll see how the backyard building can range in size and scale based on the lot number, size and zone. In 2018, the only thing that could be done with a single lot in the Single Family zone is what you can see in our 335 DADU project. Since the code changes, the new type of project could resemble the configuration of several of our completed projects, including Urban +, Urban Share, or the North lot in Row 1412. In 2022 we used our expertise in Urban + to help two of our clients approach this type of project.

An axon of the 335 DADU. This project could add an additional ADU based on new requirements.

An axon of the Judkin’s Park House. This configuration would not be allowed in Neighborhood Residential zoning due to the location and size of the two homes.

An axon of the Urban Share project. While it’s three units, this configuration would not be allowed in Neighborhood Residential zoning due to the location and size of the two homes.

The Genesee ADU Cluster in West Seattle will add five residential units across two sites of current single family homes. One of these primary residences will be retained and converted to the allowable DADU for that lot. The other existing residence will be removed to make room for the new dwellings. The duplexes (or Single Family w/ ADU) that face the two streets are three stories with living on the second floor. Each new unit has at least two bedrooms, with the two larger units designated as Single Family Houses having three bedrooms. Similarly, in our project Urban Share, a Single Family home remained on site while a duplex was built behind it. If Urban Share were on a Neighborhood Residential zoned lot today, the two small units in the duplex would be comparable in size to what is allowed now as an ADU or DADU.

The Genesee ADU Cluster retained an existing Single Family House.

Due to being a corner site with access to two streets, we are position the existing Single Family house behind a new structure, and designate it as the site’s DADU.

The site plan for the Maple Leaf ADU Cluster is organized to give each of the three units a private outdoor space. While each of these spaces is accessible to all three units, they are recessed from the street and are configured like a checkerboard with each unit exiting through a rear door onto an established space. Due to the new code allowances, parking is only provided for the front Single Family home in a ground floor garage.

In the end, the driving factor for the large increase in ADU and DADU development in Seattle is cost, specifically related to the process required to obtain a permit for construction. These three unit projects, while being similar to a three unit townhouse project, are not required to participate in the city’s Design Review program, or comply with the requirements of the Mandatory Housing Affordability program. This streamlines the entitlement process, and saves money while being more predictable. While this will help bring the much needed residential units to the area, it will increase the amount of small ADU and DADU units that come to the city, which offers a more affordable option in the market.

Happy New Year! At b9 architects, we have the good fortune of having a large portfolio of completed works. Due to the diligence and expertise of our clients, the majority of the residential projects we’ve designed are completed, a feat not all architecture firms have. In 2022, we examined a couple projects that, due to the economic realities of Seattle, were canceled mid-process. Due to the increasing costs of construction, longer permit entitlement processes, and current incentivisation programs in the municipal code - creating dense, rentable residential units is not always cost effective, especially on small or complicated sites. Here are case studies of two projects that did not move forward.

Midvale Apartment

The Midvale Apartment Building and its surrounding neighborhood were up zoned when the City of Seattle implemented the Mandatory Housing Affordability (MHA) legislation in 2019. Properties facing the main arterial, Stone Way, remained in the Neighborhood Commercial zone but received a height and allowable area increase.  The neighborhood to the west was largely shifted from the exclusive Single Family zone to the more flexible Residential Small Lot zone. Our site, however, and everything on the half block between the two received the intermediate Lowrise Multi-Family designation. 

As a potential transitional space between the more active Commercial Stone Way and the classic Seattle Single Family neighborhood, this site appeared to us as a space designated for small-scale, dense, rental housing. But in implementation, the zoning allowance does not reflect the true cost. A family-sized unit requirement, a one-time MHA fee payment, and construction complications made an apartment building at this site with the height and area restrictions infeasible. 

This Axonometric View of the surrounding blocks of the proposed project on Midvale Avenue North represents the existing zoning and development and in particular, it diagrams the different scales of surrounding residences and buildings between zones

While the MHA implementation unlocked this half block strip for potential multifamily redevelopment, higher density housing came with a family-sized unit requirement. For every 4 proposed units, one 2-bedroom (minimum 850 square feet) or for every two 2-bedroom units a single 3-bedroom unit (minimum 1,050 square feet) must be provided. In addition, any development under MHA (that does not provide affordable housing on site as part of the development) incurs a fee that must be paid to the city of Seattle before a building permit can be issued. The fee is a variable dollar amount per square foot that changes based on location within the City and the extent of the upzone. Alternatively, a project can choose to designate a portion of their units to rent for significantly less than market value for the first 75 years of the project. In our experience, the client almost always chooses the fee due to the complication of renting units through a city managed program and the future potential loss of rental income. At the same time, construction costs due to a lack of staging space on midblock sites, supply chain issues, and other national economic difficulties caused our client to rethink this project and focus elsewhere. The multiple requirements that previously would have made the projected income tight, but feasible, became too constricting as the project became short on projected rental income and desired number of overall units. We believe the zoning intended to create small apartment buildings with family-sized units, providing increased density near a commercial zone while also transitioning towards the more residential blocks of the existing neighborhood. Instead, due to the complexity described above, small townhouse structures and additional single family dwellings are being developed along this same zoning block. This is achieving a greater density than what previously existed, but still is creating single-family living at higher cost to future residents. Following the permitting of the small-scale 13-unit apartment building, our client chose to sell the site, resulting in the creation of a single family unit and a duplex structure.

As much as the City of Seattle needs to solve the lack of affordable housing and needs the addition of more family-sized rental units to the housing market, passing the cost of multiple housing initiatives - when applied at such small infill sites - onto the developer incentivizes the developer to avoid them entirely, where they instead pursue more predictable  projects with a greater financial upside and less risk.

Pictured is the proposed apartment project viewed from Midvale Ave N to the Northeast

An entry sequence was designed to bring residents and guest to the central open space of the site

The central space was designed to feel very open to allow air and light to activate the site and shared apartment spaces and to provide neighboring sites with massing relief

Fir Street

A very small site in Seattle’s Midrise Residential zone, the Fir Street project came to b9 architects as an apartment, proposed to take advantage of the increased capacity allowed under the MHA upzone. 

The site is located on a small peninsula of Midrise zone that is adjacent to the Yesler Terrace Master Planned Community and to the south of a small Neighborhood Commercial zone.  This site is visible from adjacent rights-of-way as it is surrounded by two parking lots and a garden owned by the neighboring Japanese Baptist Church to the west and the north, with an alley to the east. A pocket park is located across the street and the immediate context features many large new multifamily apartment structures that are part of the Yesler Terrace Master Planned Community.  

This Axonometric View of the surrounding blocks of the proposed project on E Fir Street and Broadway depicts the existing zoning and development and in particular, it diagrams the much larger scales of surrounding residences and buildings as well as the relative small size of the lot occupied by the proposed project.

The originally proposed massing for apartments on E Fir Street

The site dimensions and height allowance result in a vertical structure that helps anchor the pocket park across E Fir Street to the south and respond to the larger surrounding developments.  The proposal addresses this unique circumstance and emerges from a clear design concept. In response, the massing consists of an aggregation of “basalt columns” of various widths and heights.  These columns combine to create a subtle, yet dynamic building mass and landscape concept.  This design concept produces numerous modulations and material changes along all facades of the building.  The termination of the “columns” at different elevations along the facade creates opportunities for balconies, which further activate the facades of the building.

The project’s height is consistent with many of the newer buildings in the Yesler Terrace Master Planned Community to the south and west while the footprint is more consistent with the fourplexes, townhouses, and smaller apartment buildings to the east and north. Due to the small lot area, 2,400 square feet, the building would be unlike anything in the neighborhood. An innovative, 6-story apartment building, this Yesler Terrace project, touted by the DJC as an “infill infill project” would have yielded 15 rental units. The project was required to go through the city of Seattle’s Streamlined Design Review process as part of the permitting process.  Through this process, we proposed modifications to reduce the setbacks required in Seattle’s land use code in order to achieve the project goals of an infill apartment on this incredibly unique site. In our experience Design Review can and should allow for flexibility in order to respond to unique sites such as this one.  The design proposal was significantly less area than what is allowed by code. Unfortunately, the Design Review process resulted in a strict application of the land use code, eliminating the necessary area to make the “infill” infill apartment feasible. That, combined with the cost of construction, became untenable and so the project shifted to a less risky townhouse scope.

The proposed massing for the project featuring 15 units provided on site

The current proposal for 3 townhomes on the same site, currently in process

The height and capacity allowance in the Midrise zone, does not have the incentives necessary to take full advantage when the site does not conform to certain characteristics including size, access to utilities such as storm and sewer, and being clear of environmental critical areas like steep slopes or wetlands. While b9 architects, inc. enjoys designing townhouses and seeing their impact on the City, we recognize a need for a variety of housing solutions.

Over the past 20 years, b9 architects has garnered expertise in maximizing Seattle’s sites in smart and well-designed ways. Clients often choose our firm to help them navigate difficult sites, or design innovative projects to compete with larger rental properties down the street. In our experience, these small 10-30 unit infill apartments tend to be the projects most difficult to meet the financial model necessary to build. If the market isn’t completely on board, developers stop completely or change typology.

In 2023, we hope to explore ways to incentivize small and medium multifamily solutions to help our clients and partners better achieve the combined goals of better, denser, and more affordable housing in Seattle’s neighborhoods.  This will include examining the necessary code changes to expand the access to housing opportunities and levels of affordability in the current Neighborhood Residential zones.

In mid-April, Principal, Bradley Khouri, and Project Architect, Brian Johnson, sat down with our Administrative Lead, Michael From, to have an in-depth conversation about 11th and Aloha, our latest completed project in Seattle’s Capitol Hill neighborhood. The 4-story, b9-designed apartment structure, consists of 34 1-bedroom and studio units and a network of exterior spaces.  These vary in privacy and include street-level private patios, exterior walkways connecting to units, a multi-leveled courtyard, and a communal roof deck. It sits on a sloped corner lot, appearing to transition from a 4-story structure to 2-stories. The exterior facades consist a modern composition of red brick, Swiss Pearl siding, steel balconies, and stepped concrete planters. An open breezeway from E Aloha Street cuts through the massing and connects to the external circulation and multi-leveled courtyard.

This project is particularly special to us, due to its contextually responsive design and location at a transition from Single Family to Lowrise Multi-family zoning. This is a stark difference in density, height and parking requirements, and it is at the edge of a highly established and historic part of the neighborhood. With proactive engagement from the design team and neighboring residents, and investment from our client, what could have been a highly contentious design process became an adaptive and collaborative effort. Bradley and Brian reflected on this particular stage, and how it embodied our values, ultimately leading to the success of the final design.

When a project in the city of Seattle goes through the full Design Review process, it is presented at a minimum of two public meetings. First at an Early Design Guidance (EDG) meeting, where multiple massing alternatives are reviewed, and second, months later, at a Recommendation meeting, where a more developed design is presented. A board of volunteers, consisting of design professionals, development professionals, local business owners, and neighborhood representatives makes comments and suggestions to the design team to ensure that new developments meet the intent of the City’s and Neighborhood-specific Design Guidelines. At these meetings, members of the public are encouraged to provide feedback regarding the design proposal through public comment. Bradley presented the initial design for 11th and Aloha to the East Design Review Board of the City of Seattle, providing 3 design alternatives based on extensive site and context analysis. “At the time, we thought we were going to present alternative three and they’d say go for it,” Brian reflected. Fortunately for the now completed project, the presentation was not as straightforward as Johnson anticipated.

While the Board gave the project team guidance typical for a project of this type, several members of the Single Family neighborhood to the north and east of the site were vocal about their concerns, centered particularly around height, bulk, density and parking. After the meeting ended, the team from b9 architects and self-selected members of the neighborhood decided to schedule a meeting to discuss how to move forward with a design that met everyone’s goals.

The proposed building changed significantly between the first two meetings. The massing, originally bold, anchored at the corner of 11th Avenue E and E Aloha Street reduced significantly, particularly at that corner. At the first meeting with the neighborhood team, b9’s client made a pledge to the group that the building would have a high-quality cladding. “Having that pledged opened up things that we had never explored before in the practice,” Brian recalled. To complement the context of the neighborhood, the team chose to clad a significant portion of the building, notably the frontage to E Aloha Street with Inca colored, Mission brick from local Mutual Materials. Two volumes, one clad in high-quality white Swiss Pearl panel, and the other in gray corrugated metal panel rise above the brick volume. The materials help indicate the change in scale as the building moves away from E Aloha street and articulate variation in the building massing.

Another significant change was that the main entry was relocated from E Aloha Street to the southernmost edge of the building on 11th Avenue E. “We had to think of 11th Avenue E as a front. When it became the more prominent facade, we were able to shift the entire building away from the street and create a strong brick base with landscaping buffering it from the street,” Bradley said. By placing the entry on 11th Avenue E, a flat street at a lower elevation, the design team was able to maintain the project’s unit count, while lowering the overall height of the building. 11th and Aloha, in its finished state, rests under the allowed height limit by almost a full story. Even though the move created a few basement units, b9’s signature courtyard community space (in this instance with multiple levels) hollowed out the southeast corner of the structure allowing an additional light source to all units adjacent to it.

After the three weeks of intensive redesign, b9 invited the neighborhood team into their office to see a newly revised project, designed around the feedback shared. The neighborhood group stood behind and celebrated the changes made. They became advocates for the new design, recommending it to the full group. In the end, they endorsed the project with a letter to the city, and their support played a significant part in the final approval by the Design Review Board at the Recommendation meeting.

The core of 11th and Aloha is a story of a collaboration between the design/development team and the neighborhood community group surrounding the project. “This group of neighbors knew what they could do, and they actually wanted to work toward a solution,” Brian remembers of the process, “a lot of the success can be attributed to both groups acting proactively”. What resulted is an elegant solution to a specific zoning condition, one that is both unique to the site and also prevalent throughout other Seattle neighborhoods. The final design reconciles the contrast between an established Single Family neighborhood with the necessity of increased density, and a development boom happening in Seattle’s Lowrise and other multifamily zones.

“My proudest moment was winning over the group in that first meeting in our office”, Brian said, “feeling the camaraderie after we showed them that brick building. From that moment on, they were 100% behind it.”

“They became part of our team,” Bradley attested.