Posts in Backyard Cottages
ADUs 101 and the Future of Seattle Housing | A Conversation with Matt Hutchins

Chris Walter, @ChrisWPhoto, talked with Matt Hutchins about the significance of Accessory Dwelling Units (ADUs).

At CAST architecture, we have been focused on ADUs for more than a decade. They're fun to design, perfectly fit a niche for new housing in established neighborhoods, and provide many benefits for owners and residents.

https://www.youtube.com/watch?v=PJaLht9v5Yw

CAST’s Cedar Cottage is a City of Seattle Pre-approved DADU. Our vision is to adapt the high-design cottage, simplify it, and make it accessible.

See more at www.castcottages.com

“Part of the reason we love backyard cottages is just the opportunity. If you have a home with a possibility for a second house – it could be whatever you want it to be – a studio, a place for grandma, a rental, and having that flexibility is huge. We have people who have it as an Airbnb, or a long-term rental, as a place for their kids and then their retirement home. This flexibility is fantastic. It opens up so many opportunities in this great city.”         -- Matt Hutchins, AIA, Certified Passive House Designer

Backyard cottages = Flexibility and Opportunity

Sedge Cottage

New sedge backyard cottage: 3 bedroom DADU

At 997 net square feet, the Sedge Cottage is a highly livable footprint that provides well-daylit space for living, necessary storage, flexibility on many sites, and two covered outdoor porch spaces. Within its compact form, the design features three bedrooms and two baths, a galley kitchen with a peninsula and plenty of storage. It features a bedroom and 3/4 bath on the main level that works well for an aging parent, as a guest room or work-from-home office. Standard, wood-frame construction, vented shed roof, slab-on-grade foundation, the careful placement of windows, and a simple exterior allow for low-cost construction without sacrificing durability, function, or style.

The design is under the height limit and can fit on the smallest lots, around trees, or on sloped lots, with space for adjacent parking if desired. The outdoor covered area is perfect for a BBQ and the cottage can be oriented toward the principal residence for multi-generational living around a courtyard. The front porch clearly marks the entry of the accessory dwelling.

The design targets 4-Star Built Green, with details for reduced air infiltration, energy-efficient heating, cooling, and water heating systems, passive solar heat gain in window/shading in summer, low-VOC finishes, no fossil fuel appliances, and all LED lighting.

See more at CASTcottages.com

Sitka Cottage

New Sitka Cottage: 3-bedroom DADU

At 1,000 net square feet, the Sitka Cottage features three bedrooms and two baths upstairs, an open living room and kitchen, storage, and an additional powder room tucked away on the first floor.  It fits flexibly on many sites with a walk-out terrace off the living room/kitchen. The three bedrooms upstairs are reasonably sized and work well for a family. Standard, wood-frame construction, vented shed roof, slab-on-grade foundation, careful placement of windows, and a simple exterior allow for low-cost construction without sacrificing durability, function, or style.

The design is under the height limit and can fit on standard to small lots, around trees, or on sloped lots, with space for adjacent parking if desired. The cottage can be oriented toward the principal residence for multi-generational living around a courtyard. The front door is on the corner and can be placed on either the short or long side of the design, depending on site orientation.

The design targets 4-Star Built Green, with details for reduced air infiltration, energy-efficient heating, cooling and water heating systems, passive solar heat gain in window/shading in summer, low-VOC finishes, no fossil fuel appliances, and all LED lighting.

See more at CASTcottages.com

New Missing-Middle Housing - Hawthorne Hills Three

Hawthorne Hills Three:
Single-family residence, ADU & DADU

This project renovates an existing home and adds an attached accessory dwelling unit (AADU), and a detached accessory dwelling unit (DADU) to thoughtfully develop this single-family home into three rental units in the desirable Hawthorne Hills neighborhood of Seattle. It brings forward a model of urban density, providing much needed ‘missing middle’ housing. The exterior of the two buildings is unified in onyx-grey fiber cement siding with cedar accent areas. The home is 4-Star BuiltGreen certified.

The main home, with three bedrooms at 1,150SF, is renovated for modern living. The kitchen features three skylights that maximize natural light and brighten the core of the home. The original warm oak floors were refinished and unify the spaces.

The 410SF AADU takes advantage of the original house’s slightly set back position on the lot to build a new unit to the front and side setback.  The entry opens to the bright kitchen and living space. Within the compact footprint, a hallway through the utility room leads to the bathroom and a separate bedroom.

The backyard cottage is a 1000SF two-story home. Situated on the lot for privacy, a private walkway leads to the front door. The DADU boasts three bedrooms with vaulted ceilings on the top floor. Downstairs, a generous great room and kitchen with expansive glass doors open to the patio and private backyard. The efficient, open plan and bonus storage add to the versatility of the home.

See more here.

TEAM
Builder: Cadre  General Contractors
Civil: Davido Consulting Group/Watershed
Survey: Terrane
Structural Engineer: Owen Gould
GeoTechnical: Cobalt GeoSciences
Andersen Windows & Doors

Photography: Peter Bohler

Beacon Hill Cedar Cottage

Beacon Hill Cedar Cottage is one of CAST’s City of Seattle Pre-approved cottage plans

Designed by CAST and built by the homeowner who is also a contractor, Beacon Hill Cedar Cottage includes the amenities and feel of a larger home. Its efficient footprint provides two bedrooms, well-daylit spaces, lots of storage, and a covered outdoor living area.

Bathed in sunlight, a generous central area includes the kitchen, dining, and living spaces. Carefully placed large windows and glass entry doors flood the area with light that bounces off the white walls to make it feel larger than its square footage. The open glass doors and deep eaves create a vibrant indoor/outdoor living experience.

The durable Japanese cypress exterior is treated using the traditional Shou Sugi Ban technique, ensuring both beauty and natural resilience.

With two bedrooms, and maximized storage throughout, there is plenty of room to keep things close at hand to pursue hobbies and work from home.

Square Feet: 707 + 147 SF patio

Photos: Peter Bohler Photography + Director
Shou Sugi Ban exterior: Nakamoto Forestry
Windows: Marvin  

See More: Beacon Hill Cedar Cottage

Washington HB 1337 and HB 1110 pass both houses

Statewide efforts to boost housing options make headway

This past legislative session, several bills made it through both houses and each will have long term benefits for the production of urban infill housing types such as cottages, ADUs, and small stacked apartment buildings.

HB 1337

The passing of HB 1337 expands housing options by easing barriers to the construction and use of ADUs.

·        legalizes two ADUs per lot in any configuration of attached/detached

·        legalizes an ADU on any lot size that’s legal for a house

·        legalizes ADU size up to at least 1,000 SF 

·        legalizes ADU height up to 24 feet

·        ends requirement for owner to live on site

·        caps impact fees at 50% of those charged on houses

·        lifts parking mandates within 1/2-mile or 15 minutes from transit stop

·        prohibits design standards or other restrictions more stringent than what applies to the main house 

·        legalizes ADUs to abutting property lines on alleys

·        legalizes ADUs in existing structures that violate current rules for setbacks or lot coverage

·        prohibits requirements for public right of way improvements

·        legalizes the sale of ADUs as condominiums

HB 1110

The Middle Housing Bill will mandate that medium and large cities create development standards for their lowest density zones to accommodate more housing.  For Seattle, it means:

·        Up to 4 units on any parcel not previously limited by an HOA or PUD.

·        Up to 6 units on parcels that are within ½ mile (a 10 minute walk) of frequent or fixed transit

·        Up to 6 units on any parcel if 2 are designated as affordable. 

The form that these new housing types will be open ended, but the Department of Commerce is busy developing a model code for cities to use as a starting point.  The deadline for cities to comply is 6 months after their next comprehensive plan cycle (for Seattle that is mid 2025). 

As one of the region's leading voices for abundant and affordable housing choices, we have been advocating for backyard cottages—accessory dwelling units (ADUs)—since Seattle first considered them citywide in 2009.

More efficient land use is critical to address our housing crisis, climate change, and persistent inequities in access to housing opportunities. Modest infill houses like ADUs are a key strategy to empower citizens to provide new housing, build generational wealth, and leverage taxpayers’ investment in infrastructure, transit, schools, and parks. 

What are some of the main benefits of living in a tiny home?
ADU, DADU, backyard cottage, interior

Seattle architect talks about the BENEFITS OF LIVING IN A TINY HOME

CAST is featured in ISN’s article: Tiny Home vs. Traditional Home: What You Need to Know

Tiny homes and small space living offer a bevy of rewards to those who decide they don’t need many things and are ready to streamline their life. There are many reasons to choose small space living. Some people may want a house that moves with them, to not have a mortgage, or simply to live lightly. 

Lower Energy Usage

Tiny homes consume less energy and cost less to maintain. Smaller appliances are typically more efficient. One will use less energy, and water, and create less waste. A tiny home could potentially be heated with a wood stove and powered by a solar array. 

It Costs Less 

Tiny homes cost a fraction of the price of traditional homes. The cost to own or rent will be significantly less and they cost less to maintain. Since small spaces use less energy, there will be less outlay on all bills related to the home. Reducing housing expenses may let owners/tenants save money for (or in) retirement, travel, or allow them to decide to work less.

Streamlined Maintenance

A tiny home is easier to maintain. With fewer appliances to repair, less exterior area to maintain and even less space to clean, those who live in small spaces may have more time to spend on work, fun hobbies, and their relationships.

Mobility

Tiny Homes can be made to be mobile. Whether it’s a vacation or a new permanent spot, a tiny home can be built to travel.

Minimalist lifestyle

De-clutter. There is only room for the important things and those things that matter most. Plus, there is also the opportunity for more focus and less distraction. A tiny home can be constructed from recycled, repurposed, and salvaged items.

Eco-friendly living lifestyle

By using less energy tiny homeowners reduce their carbon footprint. There is only room for vital appliances, so you save on electricity bills. Also, there is the potential for minimal expense on a rainwater collection system and composting toilet. The tiny home can be designed to be completely off-grid.

Photos by: Cindy Apple Photography

Seattle DADU, ADU, exterior


Can I be more sustainable by living in a tiny home?
Seattle DADU, kitchen, backyard cottage, interior

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

sustainable tiny home,  Methow Valley

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

See more of this tiny home on our website.

How architects are advocating for ADUs in high-cost urban areas

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.

Seattle ADU, DADU, backyard cottage

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

URBAN DENSITY In Seattle’s Montlake neighborhood
Seattle ADU, DADU, missing middle housing

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