ADU + DADU: Living Small, Living Well

Accessory Dwelling Units (ADUs) and Detached Accessory Dwelling Units (DADUs) are transforming the housing landscape in urban areas. These self-contained small homes, can be attached or stand-alone and are becoming increasingly popular in cities grappling with housing shortages, rising costs, and shifting lifestyle preferences.

Help Housing Shortages
The surge in demand for housing has put significant pressure on urban neighborhoods, where space is limited and housing affordability is a critical issue. ADUs and DADUs offer a practical solution by increasing the housing stock within existing neighborhoods.

Affordability + Flexibility
ADUs and DADUs provide an affordable alternative for renters and homeowners alike. Homeowners can use these units as rental properties, offering housing at a lower cost than traditional apartment units. They can also serve as multi-generational living spaces, allowing families to stay connected while maintaining privacy. For many, ADUs are a way to downsize without leaving their neighborhoods, contributing to economic diversity in communities.

Ease Zoning Regulations
Cities across the US are revising zoning laws to encourage the construction of ADUs and DADUs. These policy changes make it easier for homeowners to build these units by reducing permitting costs, relaxing parking requirements, and increasing maximum allowable sizes. In Seattle, for example, pre-approved DADU plans streamline the process, saving time and money for homeowners.

Sustainability
These small homes align with urban densification goals. By utilizing existing infrastructure and minimizing the need for new developments these homes help reduce urban sprawl. Additionally, their smaller size typically results in lower energy consumption.

Enhance Community Character
Thoughtfully designed DADUs can blend seamlessly into existing architectural styles, adding diversity to the housing stock while preserving the integrity of the neighborhood.

See more: www.castarchitecture.com/backyard-cottages-new

Elin HeadrickComment
CAST's Matt Hutchins focuses on innovative solutions to promote accessible, medium-density housing

Matt Hutchins addresses the critical issue of “missing middle” housing in the U.S., exploring the housing gap that falls between single-family homes and high-density apartments. Serving as a jury member for the Denver Single-Stair Housing Challenge organized by Buildner, he focuses on innovative solutions to promote accessible, medium-density housing options.

Watch on YouTube: https://www.youtube.com/watch?v=orW8tnmPSv0

Missing-middle housing is a housing type that fits in the middle between single-family detached houses and larger apartment buildings. That’s duplexes, tri-plexes, four-plexes, ten-plexes, and small apartment buildings. It’s any sort of increment of density that is greater than a single-family house, but isn’t the blocks of apartment buildings that is much of what we see in the development world today. Missing-middle housing is important for urban development because American cities have lots of space. They are nowhere near full. We have empty parking lots. We have lots that were never developed. We have space in our cities we can use or reuse. There are many opportunities within our cities to densify and make use of existing infrastructure without having to assemble a whole block or use more “high-wire acts” with regard to development.

• Make good use of small lots

• Use of single-stair buildings is a critical tactic for taking advantage of small urban lots

• Adapt building regulations and make required changes

• Use underutilized urban land

• Use space correctly

• We have already invested in the urban infrastructure

• We can have a more efficient city and residents with a lower carbon footprint

• ADUs and DADUs are powerful tools to keep communities together, keep the property in family, and create generational wealth

• Missing-middle housing is compact, efficient, and sustainable


Elin HeadrickComment
Scaling Up Outdoor Preschools - white paper
preschool classroom, ELC

A growing body of scientific literature demonstrates significant benefits to young children from nature-based education. Some of these evidence-backed benefits are seemingly self-evident, such as increased physical activity correlating with lower levels of childhood obesity and enhanced motor-skills development. Constantly changing weather is a direct stimulus that develops resilience and self-regulation. Regular exposure to nature is widely recognized as reducing stress levels in people of all ages.

middle housing toolkit

Introducing CAST’s Infill Housing Toolkit: We put together recent, current, and future projects to showcase strategies and case studies for abundant housing infill development.

Site
Typologies
Constrained Lots
Typical Infill Lots
Large, Assembled Lots

Design Features
Single Stair
Stacked Flats
Low-Energy Design
Low-Carbon Building
Diverse Unit Mix
Open Space

Kirkland Cedar Cottage

The Kirkland Cedar Cottage shines. It has an extremely efficient footprint that provides well daylit living space, necessary storage, flexibility, and a covered outdoor living area.

Bathed in natural light, a generous central area includes the kitchen, dining, and living spaces. The cottage is accessible with one-level living, flush entry thresholds and flooring transitions, a galley kitchen, and a generous entry that connects the 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.

Square feet: 467

Green Design: Energy-efficient heating, cooling, and water heating systems, passive solar heat gain in window/shading, all LED lighting, low VOC recycled and renewable materials, and no fossil fuel use appliances.

Interior Designer: Jayne Douglas Design
Builder: NW Finishing
Photos: Kara Mercer

This cottage was recently featured in Kirkland Lifestyle.

Green design elements prominent in the Methow Valley's RiversMeet

RiversMeet, a mixed-use project in the town of Winthrop in Washington’s Methow Valley, is positioned to become the upvalley entrance to “old downtown.” The site is a challenging set of narrow parcels overlooking the confluence of the Methow and Chewuch Rivers.

RiversMeet is envisioned as a template for how buildings can work within Winthrop's westernization code while striving for high levels of sustainability and providing more inclusive housing options.

The program will provide two 2-bedroom residential units overlooking the river, with approximately 1,870 SF of pedestrian-level retail space. The second floor incorporates 1,870 SF of office space. The second floor incorporates 1,870 SF of office space, continuing the client’s tradition of renting below market rate to community non-profit businesses.

GREEN DESIGN
1. Concrete mix uses fly ash, reducing use of higher-carbon cement
2. Low-Carbon Foamed Glass Aggregate replaces typical underslab foam board insulation
3. Gutex wood fiber exterior board insulation
4. Low-Carbon Wildfire Resistance Strategy:
- Wood siding treated with a non-toxic solution that provides fire resistance without the high carbon penalty of fiber cement
- Exterior sprinkler system
- Fiber cement siding reduced to areas where it's most effective
5. FSC-certified wood framing package
6. High-efficiency all-electric heat pump space heating
7. High-efficiency heat pump water heating
8. Solar array

TEAM
Client: Peter Goldman and Martha Kongsgaard
Architect: CAST architecture
Builder: North Star Construction Company  www.Northstarbuilds.Com
Civil & Structural: DCG, now Facet   www.dcgengr.com  
Electrical: TFWB   tf-wb.com
Environmental:  Grette  www.gretteassociates.com 
Geotech: Geoengineers  www.geoengineers.com/ 
Mechanical: Ecotope   www.ecotope.com 
Survey: Tackman   www.tackmansurveying.com

Passive House design certified apartment building in Seattle

ECHO, a 10-unit apartment building in the Eastlake neighborhood of Seattle, is now a Design Certified PHIUS (Passive House Institute US) Core 2021 project.

This apartment building will replaces a single-family structure in this residential urban village, adding missing-middle housing. It utilizes the stacked flats concept which pushes the bounds of the single-family envelope but maintains an urbanism-friendly street frontage.

The two homes on the ground floor are both fully accessible. And, the top two units have high ceilings with lofted sleeping areas.

High-performance design elements include: thermal control, airtightness and moisture control, balanced ventilation, and high-performance glazing.

TEAM
Developer: West Crescent Advisors, LLC, Nancy Melton
Architect: CAST
Passive House Institute US: @passivehouseinstituteus
Builder: Carrig Construction @carrig_construction
Project Consultant: Woodworth Construction Management LLC, Lydia Anne, @woodworth_built
Civil Engineer: Davido Consulting Group, Inc. @dcgengr
Structural Engineer: Harriott Valentine Engineers @harriottvalentine
Mechanical Engineer: Ecotope @ecotope_inc
Envelope Consultant: B.E.E Consulting, LLC
Electrical Engineer: TFWB Engineers, Inc
Windows: Alpen Windows – Passive House Certified
Landscape Architect: @karenkiestlandscapearchitects
Arborist: Moss Studio
Geotechnical Engineer: PanGEO, Inc.
Surveyor: Terrane @terranesurveying
Third party verifier: Balderston Associates

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

RiversMeet Winthrop Proposed Mixed-use building

ON THE BOARDS - METHOW VALLEY’S RIVERSMeet WINTHROP proposed MIXED-USE BUILDING

RiversMeet, a proposed mixed-use project in the town of Winthrop in Washington’s Methow Valley, is positioned to become the upvalley entrance to “old downtown.” The site is a challenging set of narrow parcels overlooking the confluence of the Methow and Chewuch Rivers.

CAST’s client, Peter Goldman, as part of his development proposal, intends to request the town make zoning changes to allow for long-term rentals in the commercial district. RiversMeet is envisioned as a template for how buildings can work within Winthrop's westernization code while striving for high levels of sustainability and providing more inclusive housing options.

The program will provide two 2-bedroom residential units overlooking the river, with approximately 1,870 SF of pedestrian-level retail space. The second floor incorporates 1,870 SF of office space. The second floor incorporates 1,870 SF of office space, continuing the client’s tradition of renting below market rate to community non-profit businesses.

Team
Client: Peter Goldman and Martha Kongsgaard
Architect: CAST architecture
Builder: North Star Construction Company  www.Northstarbuilds.Com
Civil & Structural: DCG   www.dcgengr.com   
Electrical: TFWB   tf-wb.com
Environmental:  Grette  www.gretteassociates.com  
Geotech: Geoengineers  www.geoengineers.com/ 
Mechanical: Ecotope   www.ecotope.com 
Survey: Tackman   www.tackmansurveying.com