A Seattle Detached Accessory Dwelling Unit

Sustainable living in a tiny home

CAST is featured in Porch’s round-up: Everything About Tiny Living: Tips From the Experts

We are rethinking space and home. CAST believes tiny homes, accessory dwelling units (ADUs), and backyard cottages are inherently sustainable building options, as well as sensible answers to the housing crisis. Tiny homes require fewer materials to build, create less waste, and use less energy to power, heat, and cool when compared to traditional single-family houses. 

In addition, people who live in tiny houses will own fewer possessions and spend less overall. Downsizing will influence lifestyle in many ways—streamlining possessions, becoming more mobile, and building financial security—which leads to a lower carbon footprint. Typically, as one moves into a tiny home, other segments of life change positively as well including overall consumption of goods, services, and even food. And this, in turn, reduces the impact on the environment. Specifically, with carbon footprint in mind, the factor that will have the most impact is the size of the home.

Good design matters. Our backyard cottages are designed to be energy efficient, low cost, and built for privacy within their context. Daylighting is important in every home and especially in small spaces. Effective storage is essential. Layering and overlapping are key to designing successful small spaces while using different materials will create well-defined areas. Plan to maximize every square foot in common living areas and integrate outdoor space. Covering outdoor space makes it feel like an extension of the home, without having to heat or cool it.

Density and more efficient land use are critical to addressing our housing crisis, climate change, and persistent inequities in access to housing. Modest infill houses like tiny homes, ADUs, and backyard cottages are a key strategy to empower citizens to provide new housing, build generational wealth, and leverage taxpayers’ investment in infrastructure, transit, schools, and parks. Plus, these homes could create an affordable housing inventory.

Photo, above: Cindy Apple Photography
Photo, below: Benjamin Drummond Photography

A functional and sustainable tiny home in Washington’s Methow Valley

See more of this tiny home on our website.

Co-founder of CAST, Matt Hutchins, AIA, CPHD, recently spoke about the ADU (Accessory Dwelling Unit) Opportunity at the AIA Conference in Chicago and how architects advocate for ADUs. We’ve included a block quote of the article below, see the full article here. Thanks to the AIA and author Katherine Flynn.

ADUs are one piece of America’s “missing middle” housing puzzle.
By Katherine Flynn

In the United States, home prices rose nearly 20% last year, reaching record levels. In light of a lack of supply, neighborhoods zoned for single-family housing are being re-examined by urban planners – and architects – looking for creative ways to address density.

HOW ARCHITECTS ARE ADVOCATING FOR ADUS

In Seattle, where the cost of living is 53% higher than the national average, the pinch is particularly severe. Local architects and city officials hope that ADUs – or accessory dwelling units – could provide some relief.

On Day 2 of AIA’s Conference on Architecture 2022, a group of five panelists from Seattle discussed how architects can advocate for increased ADU production and make the process easier. Code reform, public outreach, financial incentives, and online tools all play a role.  

As Nick Welch of the Seattle Office of Planning and Community Development pointed out, Seattle—like many American cities—has a long history of redlining and use of racial covenants in residential neighborhoods. Today, high housing costs are driving displacement and reinforcing exclusion, with historically disenfranchised people being hit particularly hard.

“Much of the city is shielded from growth, and that’s very much by design,” Welch said of policies enacted by the city in the twentieth century. In the 1990s, the city adopted a growth strategy that concentrated more than 80% of new housing in about 30 designated areas called “urban villages” – largely studio and one-bedroom apartments.

“[Urban villages] helped us accommodate a lot of new growth, but it still hasn’t kept up with demand,” he said. “Single-family areas actually have lost population in recent decades, even as our overall population has soared. That means people are priced out of the expensive housing in those areas, and they look to lower-cost neighborhoods where they often will compete with lower-income BIPOC households that have lived in those areas for a long time.”

Welch acknowledged that ADUs are just one part of Seattle’s housing strategy overall, but the city pursued it because it adds lower-cost rental housing in areas that don’t have very much of it. It also provides options for families to age in place or receive passive rental income.

Currently, less than 4% of Seattle single-family lots have an ADU. To incentivize increased production, Seattle’s planning department had to rethink barriers that prevented homeowners from building an ADU, including land use codes and limited tools for financing them.

Despite several years of setbacks, including an appeal by neighborhood groups who were worried about negative impacts of increased density, code changes were adopted in 2019. They allowed for up to two ADUs on single-family lots, as well as two stories in a single ADU. The code changes also eliminated a previous parking requirement and expedited the permitting process.

To help homeowners navigate the potentially onerous process of building an ADU, the City of Seattle launched an online resource called ADUniverse. AIA Seattle was involved in shaping the guidance, as well as with pre-approval of 10 ADU designs. In the two years since the code changes were implemented, almost three times as many ADUs have been permitted. The pandemic, Welch says, may have also spurred more interest in ADUs as an option.

Matt Hutchins, AIA, of CAST Architecture, has been designing ADUs for the past 12 years.

“As architects, especially, we have the ability to capture what the future could be,” he said. “We have to make room for more people, more housing, and it’s really a matter of how we do that. We can be super effective messengers about how to tackle some of these problems.”

During his advocacy work for the code changes in Seattle, Hutchins became co-founder of a group called MOAR, or More Options for Accessory Residences.

“What we knew, and what we found out even more strongly, is that grassroots support for housing exists,” he said, emphasizing the importance of centering the narrative on positive aspects of ADUs. He and his fellow advocates also worked on building a coalition with other stakeholder organizations like AARP and construction groups. “Having this dialogue in our community was really important,” he said. An online gallery of completed ADUs helped “build a market, inform the public, and diffuse some of the criticism.”

“As architects, we have the responsibility and the skills to show how we make room for new housing, and how we create the kind of city that we want to live in,” he said.  

CAST is closely associated with efforts to improve housing affordability through increasing the “missing middle,” moderate density infill within existing neighborhoods. This work includes policy advocacy work as well as the design of DADU’s, ADU’s and small-scale apartment buildings

A modern Tudor-style cottage built to fit the neighborhood and add density to Montlake

DADUs help seattle’s density

This well-crafted modern Tudor-style cottage in Seattle’s treasured Montlake neighborhood brings forward a model of urban density, while providing a private home. A gracious entry brings you to the great room with vaulted ceilings, dark-wood beams, and loads of natural light from all four sides of the home. The kitchen is designed with abundant easy-to-use storage and generous counter space. The dining area’s large glass doors open to a patio facing inward to the property’s shared courtyard that connects the private homes and provides opportunities to gather. A lot of home fits into the 1,225 square feet with three bedrooms, two baths, flexible utility space, and creative storage. Two entrances make access to both levels of the home straightforward.

See Built Green’s case study on their website: CAST architecture Modern Tudor DADU It highlights energy efficiency, low-impact development, rainwater catchment, indoor air quality, moisture protection, and materials with reduced environmental impact throughout the home and property.

See more: Blaine Cottage

Photos by: Andrew Giammarco

Modern, functional shou sugi ban clad tiny homes on wheels in the methow valley

Like some who found themselves in lockdown at the start of the Covid-19 pandemic, this Seattle family of four realized if they were going to work and attend school online, they could do it from anywhere. Cue a temporary move to their summer place. A year into their stay, they decided they were putting down roots in the Methow Valley and decided to make the change permanent. Their out-of-the-box solution? The family spent the summer building a pair of tiny homes on trailers with the help of friends and local tradespeople.

CAST’s goal was simple: apply everything we’ve learned about efficient home planning to a design that would be buildable by non-professionals and legal to tow down the highway. This was a highly collaborative process as we sought a compromise between homeowner research into solutions pioneered by the DIY tiny-house community and our knowledge of modern construction best practices.

The result is a pair of elegant, flexible rooms-on-wheels clad in shou sugi ban charred-wood that are modern, warm, and ultra-functional.
Shou sugi ban is a Japanese preservation technique that burns wood to create a weather-proof finish. The charred outer of each tiny home is cypress harvested in Japan, milled, burned in a kiln, and sealed with oil. Over time, they will weather and gain a patina.

The simple pitched roof is matched by an outward tilting wall to create a playful form with extra headroom at one end for a sleeping loft (with a built-in desk below). The regular rhythm of high square windows makes the room feel much larger by illuminating the ceiling. At the entry side, floor-to-ceiling glass frames a wood stove, creating a cozy lounge space. Inside, a narrow service bar in the center will accommodate a small kitchen and a private compartment for a composting toilet.

Featured on Dwell+ ”A Family of Four Joins Hands to Build Two Tiny Homes in Washington”
More photos at: https://www.castarchitecture.com/mccarthyrekart-tiny-homes
Photos by: Benjamin Drummond Photography

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

Matt Hutchins was a guest presenter at Olympians for People-Orientated Places (OPOP) speaking to the value of Accessory Dwelling Units (ADU) in our communities. Matt shares details about ADU options and relevant design tips. Watch the full video here: https://www.youtube.com/watch?v=j-ZNvrlb2jM&list=PLkaUO3cFG5vm9YIeiYMNyZexq4uehfMcs
Visit www.opopnow.org/adu-101 for more details.

CAST’s Matt Hutchins: ADU 101 VIRTUAL WORKSHOP

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.

Now that the new legislation is in place, it is time to upload an updated Quickstart Guide for 2019. Keep in mind that we couldn’t get too deep into the weeds here, so if you have questions, please contact us and we can walk you through the changes in more detail.

Link to PDF

Steelaway Cottage, by CAST architecture 2018

To celebrate the final Environmental Impact Statement that came out last week, we’d like to highlight some of the less obvious but clear reasons for progressive Seattle to embrace the new ordinance covering Accessory Dwellings.

1. Many ADUs end up being affordable, even if they are admittedly expensive to build. I have made the case over and over that we should approach ADUs with our eyes open as to the cost and not put too much faith in them as a cure-all for our housing crisis. But, in surveys collected from Vancouver, Portland, Ashland, Eugene, Edmonton, the Bay Area, a large percentage (generally around 20-25%) of accessory dwellings end up being rented for nothing, very little or well below market rate. Voluntary affordability, where the owner has prioritized the benefit of having family, friends, or even good tenants as neighbors over the potential rent they could demand if they were more ruthless landlords is a major benefit of this form of housing.

Voluntary Affordability in Portland. https://accessorydwellings.org/2014/08/07/do-adus-provide-affordable-housing/

Voluntary Affordability in Edmonton. https://accessorydwellings.org/2017/09/08/garden-suites-in-edmonton-a-private-investment-in-the-public-good/

For example, I have friends who have not raised the rent in 9 years for their upstairs mother-in-law apartment because they love the tenant but she’s on a fixed income. It’s a sweetheart deal they want to last as long as she can handle the stairs. These anecdotes are the rule for homeowners who’ve ‘DIY’ developed an extra unit on their property.

In Portland among owners who live in their ADU, 41% of the primary residences where offered for FREE. Meanwhile, we’re fighting tooth and nail over an inclusionary zoning program that might create 6–10% of new housing as rent restricted. The reality is that a naturally occurring housing type people desperately want to build all over is also 2 1/2 times more likely to create truly affordable housing than our best big policy idea.

2) Making Mother-in-Laws and cottages pencil financially counters wild speculation on McMansions. In the Draft EIS, the City ran different financial models for potential development outcomes. In the draft EIS, 46% of the possible scenarios resulted in tear down/replacement McMansions being the most profitable investment. It was only in cases where the land value was high and the lots were large that adding an ADU and DADU made sense. But if you value the neighborhood and want to curb the momentum of displacement and gentrification, supporting options where a second or third household can add rental income suddenly flips the proforma against the disruptive scourge of McMansions.

3) Renters are Seattle’s majority and any related stigma is out of touch. Owner occupancy restrictions are the biggest impediment to the creation of more housing and keep lower income renters out by limiting the number of options for less expensive dwellings to exist. The checkered history of zoning as a substitute for outlawed racial or class covenants is well documented.

More than 20% of Seattle houses are already rentals. We don’t have a restriction on renting out a detached house and has very few expectations of landlords (more might be in order) yet neighborhoods still thrive. Both tenant and landlord are by and large responsible neighbors. Ask any renter, and they will tell you that they are just as committed as property owners to the neighborhoods, support the local businesses, and participate in civic life. As the majority of Seattleites, renters make up the underlying tax base that funds our government, parks, police, and transit (renters pay property taxes too, just through rent).

4) Besides, owner occupancy restrictions should be illegal. Limiting WHO can use land, as opposed to what the land’s function is isn’t really the job of the land use code. Making property ownership the prerequisite to use is unique to ADUs and has been challenged elsewhere. Other jurisdictions, such as Alberta Canada explicitly allow residency without ownership wherever residences are allowed for that reason.

Find the duplex! (Answer below)

5) Finally, extra dwellings are already everywhere. While people might worry that allowing a ADU and a DADU without owner occupancy restrictions will lead to no less that the ‘destruction of our most unique resource, Seattle’s single family neighborhoods,’ the reality is that there is a long history of small multi-family dwelling coexisting with and even predating the now dominant paradigm of stand alone houses for solitary households. Turn of the last century neighborhoods, like Queen Anne and Wallingford (pictured above), valued for their amenities, walkability, and housing stock, were developed mostly before zoning. They are filled with the highest concentration of small multifamily buildings, house more than 10,000 households, but you might never know it from the street. Honestly that is part of their charm and vitality. If the worst thing is that there are a few more families per street, I think our neighborhoods are more than resilient enough to handle it.

Here is a map of every multifamily building and accessory dwelling in Seattle as off 2016-find the hidden duplex on your street!

Every dot is at least one extra household that doesn’t need a stand alone house.

*In the photo above every structure is a duplex, triplex or fourplex, with the exception of the tallest white structure on the left.

We're almost done with a believe it or not historical renovation of a mid-century architect's own house--more to come!