Cedar Cottage, originally designed for the Phelan family

Recently, Seattle put out a call for lower-cost designs to be ‘pre-approved’ for building permits. One of the biggest challenges for backyard cottages is the uncertainty and permitting difficulty for many people who may never have taken on a big project like this before. CAST answered the call, putting together four designs ranging in size and features, derived from our long experience with the backyard cottage market. Here is a preview of the four models, each has its own special hook—sloped lots, accessibility, expandability, or super small size:

Cloud Cottage, 481 sf footprint, multiple configurations from studio, or 2 story version with studio over garage, 1 bedroom or 2 bedroom.

Kestrel Cottage—one or optional two bedroom (not shown here), all on one level for accessibility and aging in place.

Crow’s Nest, original design for Matt and Amy Stevenson, adapted for Seattle’s Pre-Approved Cottage program

Over the next month, regardless of what this City does, CAST will be developing some or all of these designs and making them available for purchase with an agreement to use CAST for the site specific engineering, permitting and zoning work. If you are interested in finding out more, contact Matt@CASTarchitecture.com.

RSL Walk ups and cottage developments create a neighborhood within a neighborhood. 

Seattle is facing a housing shortage, a climate crisis, and an increasingly inequitable city. Allowing more dwelling options, at various sizes and price points, is a great strategy to combat all three. Enter the Residential Small Lot Zone, Seattle’s attempt to add less expensive dwellings in dense, amenity rich urban centers without disrupting the historical fabric of single family detached houses. 

As part of Mandatory Housing Affordability (MHA), Seattle is rezoning many of the Urban Village parcels currently zoned ‘Single Family’ to ‘Residential Small Lot‘ (RSL). RSL exists under the code right now, but is applied to only 7 acres of zoned land in Seattle and has narrowly defined housing types and restrictions that have kept it from wider acceptance. Under MHA, RSL will be expanded to 768 acres and include about 6200 Single Family Lots. The proposed code has been rewritten from the ground up, so let’s dig in and see what it is likely to produce for Seattle’s neighborhoods. 

Function

Reading the definition of RSL, it is hard not to feel sorry for this hard working zone.

It has to be a little of everything to everyone. It is uncommon for a zone description to get into issues of affordability, children, and the desires of its residents. We don't expect the description of General Industrial 2 (IG2) to make judgments about dockworkers’ life choices. Or Downtown Office Core-1 (DOC-1) to wonder about whether people in Downtown Office Core 2 (DOC-2 ) feel development there is appropriate.

Nevertheless, it exposes a question. What is the mission of RSL? Is it a transition between Residential zones? Is it meant to capitalize on the proximity to urban centers by putting residents close to amenities, jobs and transit? Is it fighting displacement, or fostering density? What need does it serve, and what is the positive vision of that zone? Right now, it is formulated with a little of everything, including some new stuff, and takes elements from single family, multi family, bridges residential and building code with a dash of high minded mission to address family housing and affordability.  It is a little like this: 

RSL.  Not elegant, but adapted to its environment.

The Nitty Gritty: What does it look like on paper? 

What does RSL look like? 

Before RSL zone, this Single family zoned street has 28 dwellings. 

And again, after a generation of development doubles the number of dwellings:

57 dwellings on the street, double the current density, but not much change at street level. 

Prototypes for RSL Zoning

We've taken the liberty to suggest some prototypes, based on traditional 'missing middle' multifamily, optimized for this zoning.  

Bungalow Court (or the Walk Up Model) 

For lots greater than 11,699 sq.ft, this bungalow court has (6) 3BR 1466 sq.ft. primary units, and (6) 733 sq.ft. 1 or 2BR ADUs.  This walk up is really a module that can be arranged into twos, threes, any grouping based on density limitations. 

Double Up Duplex

Our idea is for a stacked duplex, 1500 sq.ft. configured for an ADU, optimized for the allowable FAR on a minimum 4000 sq.ft. lot. We'd target Passivhaus green building standard, integrate green roof, pv, and rainwater catchment.  

Alternative configurations for ADUs, or future co-housing options. 

Recommendations for code tweaks!

Here are fourteen ways we can improve the Seattle’s MHA’s totally rewritten Residential Small Lot zone, BEFORE it goes into effect:

1.Exempt RSL from MHA fees. New dwellings created in the RSL zone will be subject to MHA, but will anyone built a rent restricted house? No. Therefore, fees due at permit issuance could be as high as $45,650. It will have a dampening effect on any homeowner looking to build a second house on the back of their lot. Many of those homeowners will build an ADU instead (not subject to MHA fee), eliminating the upside of more smaller homes in the marketplace. 

2. Allow ADUs to function as MHA performance! MHA performance is 50% for lots under 5699 sq. ft.. Meanwhile ADUs are by definition limited to a smaller size, and making them affordable would be closer in spirit to the original intent of the ordinance.

3. Eliminate new Maximum Net Unit Area limit. Maximum Net Unit Area is a new, unique limitation that only applies to this zone, and nowhere else. It is Floor Area per Unit, and it is often in conflict with the Floor Area Ratio (FAR) for the parcel. There are no MNUA exceptions for existing houses or additions, meaning many of Seattle’s classic bungalows in RSL zones will suddenly become non-conforming, unable to do a ‘bump out’ or even a SECOND story addition. Because basements count toward MNUA, but not FAR, expect a lot of new buildings with basements apartments. 

A basic RSL block reveals surprising inflexibility unless you want to add a second dwelling

The owners could only do a 230 sq. ft. addition. Not a second story. They could however build a new dwelling behind it up to 2200 sq. ft.

4. Start FAR at 1, give .25 bonus for more dwellings. The FAR is .75, lower than any Low Rise zone, and effectively lower than Single Family zoning (only governed by height and lot coverage). If RSL is meant as a transition between multifamily and single family, it is more restrictive that both.

5. Lower the density ratio to 1 to 1500. Fourteen percent of the newly minted RSL lots will not even support a second dwelling. Why go through this process then wipe the development capacity of 900 lots off the table? Rounding up for density at 1.85 * 2000SF means any lot under 3699SF is still a single family lot, but MNUA effectively limits all dwellings to an FAR as low as of .59.

6. Allow more than one Accessory Dwelling Unit (ADU). All these lots are in urban centers, where we are planning to put almost all our growing population. Many lots or owners aren’t going to want to built a full second dwelling. Meanwhile, SFZ will soon allow two ADUs per primary residence. This flexibility will preserve many existing houses, and provide homes for new residents right in the urban villages.

7. Exclude ADUs from MNUA. An accessory dwelling unit counts against the MNUA, meaning many average houses wouldn’t be able to build a cottage without sacrificing square footage in the primary house.

8. Resist the urge to Design Standard. The two Design Standards for RSL are ridiculous. Different color walkways to the house in back? Why? We don’t expect such ham fisted wayfinding in multifamily zones where there’s likely more front doors. One of the great strengths of the proposed code is that it did away with the many of the restrictive types, like ‘tandem housing.’ Let’s not dilute it with well meaning micro management, only to find out that we’ve created a less than graceful solution (remember the platypus!).

9. Allow exceptions from MHA when preserving existing houses. Subdividing existing houses into multiple units will be penalized by the Design Standards, and be subject MHA fee, at the full price for the area of units. The MHA fee calculation is gloss floor area/total units X net increase of units. A 3000 sq ft house, converted into a triplex from single family, would pay MHA on 2000 sq ft as if new, or up to $41,000. That neither incentivizes preservation or the creation of more affordable housing. 

This is a triplex.  Converting it under the MHA regime would cost tens of thousands of dollars in MHA fees in addition to the requirements of retrofitting.

10.Take out limit on number of apartments. The stigma of apartment living results in one of the most efficient (and revered) forms being outlawed. The code is clear: RSL outright outlaws more than three apartments regardless of lot size. No cute Capitol Hill fourplexes.

This fourplex is not allowed under the new RSL zone. 

11. Eliminate owner occupancy requirements. We don’t require owners to live on site in other multifamily zones, owner occupancy requirements will severely limit the number of accessory dwelling units and they reinforce a fundamentally class based stigma against renters.

12. Change all residential zones to ‘Residential’. We now have three titles for zones where residences are the only use; Single Family, Lowrise, Residential Small Lot. While RSL is being treated as a unique bridge between SFZ and LRZ, it should be part of a continuum of dwelling per square foot. Streamline!

13. Amend Seattle Residential Code to cover up to four apartments. Building codes switch to the more demanding SBC for anything more dense than a duplex and ADUs are considered as such. When buildings should be getting more efficient, like stacking a third apartment on top of a double decker, there is a quantum leap in construction cost, driven by code compliance.

14. Allow Live Work and Corner stores. In midrise zones, having residential suites at the street level seems forced. Two blocks from the center of an urban village, having an office space legible from the street makes total sense. Allowing corner stores would expand the walkshed so more people will walk to pick something up, rather than drive to a supermarket.

Neighborhood institutions start with entrepreneurial neighbors. Give them a place.

We are very excited to begin a new project for the Sunset Hill neighborhood to transform an abandoned City Light substation parcel into a pocket park.  Based on the input from the community thus far, the program is very intriguing:  a community space with an artist-in-residence caretaker, powered by a serious photovoltaic array. There may be more or different elements as the project evolves in the community design process, and as we navigate through various City agencies and funding sources, but fundamentally this has all the values we expound as a firm:  sustainable building, energized public space, housing options/density, and  an interactive process that invests people in the civic life of their neighborhood.

In 2008, I designed a structure with a similar program for a Dwell Magazine conceptual competition:

Set at the east end of Crissy Field in San Francisco, this Community Room/Exhibit Hall creates an anchor for a new sculpture park. The hall is a multipurpose space, more infrastructure than building--for public events, private events, exhibits, etc. The glass sliding panels open the hall to the public, the park and the views of the Golden Gate Bridge.

A small caretaker's residence is situated on the second floor, using the broad roof of the Community Room as a vegetable garden, eliminating the conflict between the public park and the private residence. The glass screen walls provides security, and electricity--the design on the glass is created with a photovoltaic interlayer, which powers the house and hall. Stormwater is captured, stored and used to irrigate the roof garden.

While this little conceptual project may help to inform the Sunset Substation, I'm excited to apply some of this experience in designing a real world pocket park.

Stay tuned....

Here at CAST we have been watching the Seattle City Council very closely over the past few months as they contemplate passing an ordinance that would allow homeowners to construct backyard cottages, or DADUs (detached accessory dwelling units), on their property... The measure is of particular interest to me as I'm a proponent of multigenerational living. If passed, the ordinance would provide greater flexibility for Seattle homeowners who wish to bring their families closer together. Curious what the ordinance would mean for my own property I spent a little time putting together some plans...

For my own property I envision a studio space above our existing garage that will provide a place for friends and family to stay during extended visits...

If you live in Seattle and are interested in seeing the measure passed by the council, please take a minute and email your Seattle city council members with your support:

Planning Land Use and Neighborhoods Committee: Sally Clark; sally.clark@seattle.gov (Sally is the committee chair and in charge of getting the measure to vote) Tim Burgess; tim.burgess@seattle.gov Tom Rasmussen; tom.rasmussen@seattle.gov Jen Godden; jean.godden@seattle.gov (alt. member)

The remainder of the council is: Richard Conlin; richard.conlin@seattle.gov Jan Drago: jan.drago@seattle.gov Bruce Harrell; bruce.harrell@seattle.gov Nick Licata; nick.licata@seattle.gov Richard Mciver; richard.mciver@seattle.gov

We have been working hard to get the City of Seattle to agree to allow Backyard Cottages, or DADUs (detached accessory dwelling units). It gives owners opportunity and choice to provide additional housing for rental or a studio, will increase property values and does so in a measured way that is conscientious of neighbors and the single family neighborhood fabric. The current legislation will allow fifty per year--so it will have a minimal effect on neighborhood character.  If anything, I'd like to see more of them.

I find it amazing that this is at all controversial, considering you can put an detached accessory building or garage on your lot which may not be as tall, but can take up to 1000 square feet of your back yard!   The argument that this proposal will lead to less trees and green space in Seattle is a red herring.

And since attached accessory dwellings are already allowed outright, it also doesn't make sense that this proposal will lead to more density.  More likely, it will lead to more people choosing to build a small cottage than expanding their existing house to provide for the mother-in-law.  Two smaller structures are better for the scale of the city than more larger houses.

Carriage houses are successful component of many cities' neighborhood fabric and we'd like to see them allowed in Seattle too!  If they were, I'd build one--my neighborhood and site would be perfect for a little cottage--so here is my first pass....

I need a shop space, my wife needs an home office, and both of us need a place for our parents when they are in town for extended visits.

The building's footprint is roughly 40 x 14 with an airy studio (or 1 car garage with ample storage), and a guest bedroom and bath on the first floor.  Stairs lead up to a loft office overlooking the garden.  The design has some additional flexibility built in--the garage can be built with the rough in for a kitchen, so with minor changes, we'd have a 2br/1ba cottage.

We have been talking to an excellent local contractor with experience in prefab about teaming up to deliver a few prototypical designs for a fixed price (including ground work) somewhere around $210 a square foot, but one-off custom stick built cottages will be competitive in price, and adapt to the unique conditions of each site--existing lot coverage, location of existing buildings, solar orientation, parking, matching materials etc.

Before we do any real development, the City Council needs to green light the ordinance.  So you support the legislation, email the council!