We have been working with a couple who are planning on moving out of the original house, and into a new backyard cottage.  We're pushing the limits within the ordinance--almost exactly 800 square feet--in order to build a 2 bed room, bath and a half cottage. Although the house is small, the spaces inside feel just right.  And we'll be able to include a lot of high finish touches and crisp details because we aren't spending money on lots of square footage. Having a finite perimeter and volume really focuses the mind on the priorities of the design.

The character of the house the client's wanted is very craftsman and the scale and roofline fits right in with the neighborhood in general--certainly not the scary developer vision that opponents of the ordinance summoned during the public hearings.  It reinforces that these projects are for people with a vested interest in both their property and their neighborhood and are very sensitive to the impact on their neighbors.

Here is another view which shows off the walkout patio off the dining space, the entry mudroom and the band of windows that wrap the living room, dining and kitchen:

We are also going to integrate a rain water harvesting system, radiant floors on a super efficient combination boiler, vaulted ceiling upstairs, and a extra height crawlspace with a rat slab to make up for some of the storage space lost in the downsizing.  For floor plans, follow the jump below:

First floor plan:

Second floor plan:

The Seattle channel recently interviewed myself and CAST clients Kate Lichtanstein and Ric Cochrane regarding the backyard cottage we are currently working on together. They included our project in a broader story that profiles an owner of a recently completed backyard cottage and gives a basic outline of the new Seattle backyard cottage ordinance.

Seattle Channel Video can be played in Flash Player 9 and up

UPDATED AUG. 8th 2019

Now that the new legislation is in place we’ve updated Quickstart Guide for 2019. Please keep in mind that this information is intended as a high level primer for the code that governs backyard cottages in Seattle… It should only be used as a basic starting point for planning. If you would like to move forward with the design and permitting of a backyard cottage for your home we recommend careful scrutiny of the entire ordinance and the assistance of an architect or design professional.

Download guide as a printable pdf

We've seen an unexpected level of interest in backyard cottages in the 2 months since the new ordinance has been in effect. Perhaps the most interesting thing about the projects is the diversity of needs for each one... We have a young couple with a small house on a large lot that would like an outbuilding with a workshop and guestroom. We have a couple planning to build and occupy a cottage in their backyard in order to open up their home for their children and grandchildren to live in. We have a third couple who have separated but are committed to raising their children together. They currently live in the same house and believe that adding a backyard cottage to the property will maintain the proximity they need to raise their children together while providing them the space they need as individuals.

In a bit of a surprise, we have yet to see anyone looking to build a cottage for the sole purpose of rental income. Although one of the guys here at the office has been running the numbers and is strongly considering building a cottage for rent in his backyard.

We can't seem to get enough of Seattle's new citywide backyard cottage ordinance...

In addition to the two custom solutions we are currently working on we've also started up plans for a prefabricated backyard cottage. Designed to be trucked to your home and assembled in minimal time, this compact home is your ticket to instant gratification. If you are looking for a space to make art, stash guests on extended stays or earn a little rental income - look no further...

The first floor features the living, kitchen and dining rooms as well as a bed and bath. A double height space over the living room and a portion of the dining room brings light deep into the interior and provides a feeling of spaciousness.

The second story loft looks out over the living and dining rooms and has space for an office, a guest bed and overflow storage.

The cottage is designed to ship on a single semi and assembled in minimal time. We're currently working with a regional manufacturer and a local builder to see if we can get the price point to come in under what you would pay for a similar site built structure... Send us an email or give us a call if you would like us to keep you posted.

The Department of Planning and Development (DPD) has posted a new client assistance memo (CAM) to outline the citywide backyard cottage ordinance. CAMs are guides intended to help people navigate the building permit processes in the city of Seattle.

CAM 116B, Establishing a Backyard Cottage (Detached Accessory Dwelling Unit) "This Client Assistance Memo (CAM) explains the requirements and process for establishing a detached accessory dwelling unit (also called a DADU or mother-in-law unit) on an owner-occupied Single Family zoned lot in southeast Seattle."

If you are considering building a cottage in your backyard it is still worth reviewing the DPD's older, more comprehensive (but now somewhat inaccurate) publication: "A Guide to Building a Backyard Cottage in Southeast Seattle."

Greenwood resident Kate Lichtenstein contacted us last spring to help her design a backyard studio / guest house for her modest 650 square foot 1920's one bedroom home (shown above). While the home's scale fits nicely with Kate's desire to have a simple and ecologically responsible lifestyle it falls a little short when it comes to a rough and ready workshop space for art, bicycle repair, ski tuning and building projects. Kate's home also lacks the space for a home office / guest room - something that she would like to integrate into the new structure.

Our initial goal was to have her project under construction by late summer 2009 but we were unable to get the project off the ground by that time. In hindsight, the stalling of the project turned out to be a stroke of luck...

In March of 2009 Seattle Mayor Greg Nickels proposed legislation that would allow Seattle homeowners to construct backyard cottages on their property. The legislation was reviewed and ultimately passed by the Seattle city council on November 2nd 2009 (with a 9 to 0 vote too! Kudos to Seattle voters for electing progressive urbanists for city council members!).

For Kate the ordinance has opened up new possibilities for a structure that can both accommodate her current needs and provide a potential source of income as a rental unit if her finances ever fall on hard times. Besides allowing for a legal detached rental unit the ordinance also allows for the construction of a two story structure – an arrangement that will work well for Kate’s needs and will help to preserve the spaciousness of her backyard.

Kate is planning to build with a mind toward sustainability and has a special interest in using recycled building materials whenever possible (she is, at this time, planning to write a parallel blog on the topic of recycled building materials). For us at CAST architecture Kate's project is an exciting chance to test out the new backyard cottage ordinance and work with a client who is committed to building green. We see her project as an excellent opportunity to provide the general public with information about the process of designing and building a backyard cottage in Seattle. Kate and her partner Ric Cochrane are always game for an adventure and have graciously agreed to allow us to share their experience with you. To that end, we are planning to blog about Kate's project as we travel through the design and construction process. Please subscribe to our feed if you would like to follow along in future posts…

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.

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.

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).

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