Seattle zoning code

Breaking---Backyard cottages pass 9-0!

The ordinance  to allow backyard cottages in the other three quarters of Seattle just passed 9-0!  The council's comments focused on the exhaustive community outreach, successful pilot program and benefit of having this housing choice for Seattle. Excellent work by the planning commission, DPD and council.

Usually, the city's process oriented decision making can be cumbersome, and having spent hours in meetings, testifying, and communicating with council, I feel vindicated that our involvement has helped in some small way to bring some innovation to the Single Family zoning.

We're excited to design some of these--in part because of the opportunity to foster multi-generational housing, and the option of building a smaller free standing structure rather than building an addition.  Plus, it is a really fun scale--I think more people will be thinking about bonus studios rather than housing units.

My backyard cottage idea: what would you do?

northwest perspective showing clerestory band wrapping studio and office north elevation: office over guest suite to the left/studio to the right

With the impending vote on the backyard cottage ordinance, everyone in the office has been doing a little daydreaming about the DADUs and what they would build.  I have been working on a idea that started with a little ink drawing. It's now developed into a preliminary model/floor plans.  I've flipped the shed roof to have more volume in the shop/studio and worked out the bathroom so that my shop could easily be converted into an open kitchen/living space.

I have also been working out a simple steel structure, clad with structural insulated panels for easy construction and minimization of waste.  The goal is prefabrication of the components offsite, then assemble.

I'd love to try out using a geothermal pre-heating loop, with a hydronic radiant system run of a domestic hot water heater and test the new PV shingles, but that might get a bit expensive.

Seattle Backyard Cottages-Land Use meeting recap

We're almost there--the committee passed the measure to allow backyard cottages in Seattle.  Next stop will be City Council. There are some notable amendments to the ordinance--the 50 per year allowed cap has been eliminated.  The heights have changed somewhat.  A discussion to limit the cottage height to no more than 15' above the primary residence's roof (which would affect sloped lots primarily) was tabled without conclusion.

The discussion is a little strange, in that some of the requirements being tossed around are more stringent than for building a single family house.  Case in point--if this relative height limit section passes, you will need a topographic survey to prove that the cottage conforms (not required on a new house if well within setbacks and under height), thus added about $2000 to the pricetag for the drawings.  This doesn't make any sense if the city is serious about this as being an affortable option.

Another case in point--Councilmember Rasmussen was leaning toward a neighborhood notice, similar to a MUP, but the neighbor's recourse, provided the cottage design fits the requirements, is nil.  The cottage is a Level 1 decision (no notice necessary, just like a new single family house), but creating such a provision would form a special class of notice ("Here is what is happening next door, but there is nothing you can do about it.  Thanks for coming down.").

Unfortunately, I had to run out before the discussion on the privacy issue, another NIMBY favorite, but in the end the ordinance is one step closer to fruition.

You can see the entire meeting online at the Seattle Channel here.  Backyard Cottage discussion starts at 107.30.


The Planning, Land-Use and Neighborhood Committee is planning on voting on the Backyard Cottages on October 8th.  Last chance to make yourself heard on this issue! It will be a packed agenda, with discussions of the Multi-family code revision as well as the design review process (which will be mandatory in Multi-family).

Multifamily code update

L3-max-front-NE-2 In the last month, the City Council paid 3 groups to study the new MF code and flesh out some likely outcomes (good and bad) and propose revisions to the code.  It is a complex issue--the code revision itself is about 277 pages--and no doubt the Council were daunted by the prospect of interpreting the impact.  It took me two evenings just to get through the entire code and I am still not sure I've got a handle on all the ins and outs.

The three groups were the Masterbuilders Association, the Congress of Residential Architects, and Group Three (composed of unaffiliated concerned citizens).  Each group were paid 5k for their work (our fee went to CORA--not to the  8 individual participants).  Here are my impressions from the three groups:


The MBA group, lead by Arg Consulting and Pb Elemental focused on fee simple townhomes, 1200 sf-1600sf each, on both the L1 and L3 sites.  One gable style, one flat roof style option for each site given in the program.  The schemes prioritized surface parking (I think one scheme had garages).  The site designs either a central surface parking lot, accessed along a longitudinal drive or perpendicular parking off an alley.  The reduction in setbacks meant the building volumes were spread to the site edges.  These would be cheap to build--fee simple boxes, surface parking, no cantilevers--and  therefore probably the most likely to get built under the new code.  Which is depressing, when you extrapolate it to the scale of the city.

The other remarkable thing is that the MBA group left development capacity on the table in order to have straight forward rectangles.  The most dense scheme had 6 units (on 7200 sf= 1200 sf per unit) well below the 800 sf per unit allowable now.  It seems hard to believe that developers best use of the lot is solely dictated by construction simplicity.  My back of the envelop calculation would put the FAR between 1 and 1.34 (6 units X 1200 or 1600 sf per = between 7200 sf and 9600sf divided by 7200 sf lot), less than the 1.4 allowed.  The outcome of the MBA exploration is big units, minimal density, and pushed to the property lines so there is enough space to have cheap surface parking. That isn't to say that all the other groups' schemes made economic sense, but if this is their best option, the proposed mandatory design review has to have some more bite, because we'll definitely be seeing these bland site plans again all over town.


The second presenter, the Congress of Residential Architects, had a lot of diversity in both type, density, good and bad.  CORA explored ground related townhouses, high density apartments, even row houses. We tried to find the limits, loopholes and boy did we create some code compliant cringe-worthy options, as well as some good options that would require departures.  David Neiman and Bradley Khouri deserve praise for herding the cats.   Here is a little conclusion that David Neiman wrote:

"There are certainly some problems with loopholes & some flawed gating mechanisms that we identified.  The bad news is that our bad schemes are even worse than what you can do today.  The good news, however, is that the culprits aren't very hard to find, and they aren't hard to fix.  Overall, we remain strong supporters of the Multi-Family Update.  It just needs some work under the hood.

Code changes recommended to make bad schemes better:

1.  Above 1.1 FAR, the wheels start to come off the cart for most ground based housing schemes.  At 1.4 FAR most ground based housing schemes are a disaster.  We need to revisit allowable FAR & use it as a tool to reward desirable features & outcomes.  For small-lot ground-based housing, FAR needs to be kept relatively low.  For structured parking solutions, large lots, and projects that undergo full design review, higher FAR is appropriate.  See executive summary.

2.   The residential amenities requirement is far too permissive – it reduces open space to an afterthought.  It's not hard to correct.  The requirements just need to be dialed up to be more significant.  See executive summary for proposal.

Code changes recommended to make good outcomes into better outcomes:

1.    Lift the density limits to allow diverse unit types, sizes, affordability levels.

2.    Return to a 30' base height limit for all L-zones w/ a 4' height bonus in L3 for structured parking.

3.    Encourage basements by exempting them from FAR – you get a privacy grade break & create opportunities for inexpensive rental flats.

4.   Green factor.  If it were working, it would incentivize open space, privacy screening, tree planting & permeability.  It does none of those things; it simply covers your land in shrubs & your walls in vines.

5.   See executive summary for more."

There will be more information and a pdf of our work forthcoming.

Group Three:

Because this post is getting long, I am going to rapidly summarize the Group 3:  Lots of double lot schemes, and generally trying to put a bad face on each.  I am not sure if anything they put up there would be something they'd like to see built.  There was a preposterous presentation of anecdotal evidence that when houses are closer than15' to the sidewalk that window blinds are always closed, and it emotes an unsafe neighborhood, therefore the front yard setbacks must be 15' feet.  One merely has to walk around any neighborhood to see front blinds drawn--it is not a function of distance to sidewalk.  There was a recurring complaint that street trees weren't provided or required and that more of the green factor elements would die or get removed (I envisioned a truck with mobile planters with trees being carted from one property to another to fulfill Green Factor, get the final inspection, then on to the next development).  I actually agree with this--by setting the level of Green Factor too high, they will be pushing unsustainable planting (one of their schemes had a vegetable garden at the bottom of a four story light well).   And they ground the axe of allowing developers to subdivide properties to take advantage of the rounding up allowed by unit density rules.  The presentation was a pretty cynical take on the new code.

If you have questions, or comments, I'd love to hear about them!

Seattle Multi Family Code update: news from yesterday's meeting

CAST has been involved in reworking the Multi-family code for the City of Seattle--this byzantine, arcane legacy that seems to produce the dreaded Four Pack/Six Pack around a shared auto court. The proposed code is evolutionary, and at this point, has been watered to down to the point that the impact will not affect the majority of lowrise multifamily that goes up in Seattle.  It is pretty disappointing in general, but a couple of highlights:

1. The move to FAR rather than density limits for number of unit will create more demand for smaller units in the L3 zone

2.  The setbacks are reduced--good for the urban sidewalk edge, and allow raised stoops in the front yard.

3. Height bonuses for workforce housing, and green building are going to get used--an example of incentivizing good construction.

And a couple of lowlights:

1.  Green Factor's heart in is the right place, but the high baseline is going to force some heavy gaming of the rules, such as fences become 'vegetated walls', and green roofs are going to go in then be abandoned.  The city would be better off lowering the baseline and focusing it on green factors that are going to be maintained and become beneficial for the environment and the city.

2.  Density limits in L1 remain, and thus there is zero impetus to alter the 4 pack in any meaningful way.

3.  Partially below grade parking doesn't count toward FAR (that's good), but doesn't give you additional height--meaning no one is going to pay to bury the parking if they are then also not able to offset the cost with a third story of marketable square footage.

I'll post more info later....

Backyard Cottages - Multigenerational Housing comes to Seattle

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 is the committee chair and in charge of getting the measure to vote) Tim Burgess; Tom Rasmussen; Jen Godden; (alt. member)

The remainder of the council is: Richard Conlin; Jan Drago: Bruce Harrell; Nick Licata; Richard Mciver;

Seattle Backyard Cottages

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!