Nadthachai Kongkhajornkidsuk
Project Manager | Architectural Designer
Nadthachai’s interest in architecture and design began to take shape as he grew up in Bangkok, Thailand, and later relocated to the Bay Area during his high school years. He went on to earn his Bachelor of Architecture from California Polytechnic State University, San Luis Obispo. His senior thesis explored housing as an “everyday space,” examining how the built environment can foster social connection, shared identity, and collective life within communities. This work reflected his core belief that thoughtfully designed housing extends far beyond function — it has the power to cultivate belonging, deepen relationships, and strengthen the social fabric of everyday living.
Since joining The Cohousing Company in 2021, Nadthachai has focused on architecture rooted in community-centered design principles, contributing to projects that prioritize inclusivity, sustainability, and human connection. He has been heavily involved in the design and development process of many cohousing communities, including Auburn Cohousing, Newfoundland Cohousing (Killick Ecovillage), East Van Cohousing, Newt Crossing Cohousing, and Fair Oaks EcoHousing. He also leads architectural production and project coordination, guiding projects from design through permitting alongside code, structural, and energy consultants. He is currently leading the Nevada City Pre-Approved ADU Program, a set of six permit-ready home designs ranging from studios to three-bedroom units, developed under a state REAP 2.0 grant and approved by the Nevada City City Council.
Beyond design, Nadthachai helps share the firm’s knowledge with the wider community. He co-wrote the firm’s latest book, Cohousing Communities: Designing for High-Functioning Neighborhoods. He also produces This is Cohousing, the firm’s podcast hosted by Charles Durrett, featuring conversations with cohousing residents, developers, and advocates. His innovative approach to housing has earned recognition from the AIA Los Angeles Chapter, Buildner Design Competitions, and Urbanarium, highlighting his commitment to creating spaces that are both visually compelling and socially impactful.
Nadthachai has also emerged as a thoughtful voice within the cohousing movement, presenting on topics such as senior cohousing, diversity, and lived experience in community at prominent events including the 2022 LeadingAge California Conference, the 2024 National Cohousing Conference, and most recently the Cohousing & Beyond Summit. In the fall of 2025, he was appointed to the Board of Directors of the Cohousing Association of the United States (CohoUS). In this role, he brings a fresh perspective, design expertise, and a deep belief in the transformative potential of community-oriented living, helping to shape the future of cohousing across the country.
Nadthachai can be reached by email or by calling 530.265.9980.
Cohousing Communities & Affordable Housing Projects
Nadthachai has helped design these cohousing communities and affordable housing projects, facilitating participatory design workshops with future residents and serving as project manager.
Nevada City, CA · 6 home designs · Approved by City Council
Nevada City Pre-Approved ADU Program
Six permit-ready accessory dwelling unit designs, from studios to three-bedroom homes, developed with the City of Nevada City under a state REAP 2.0 grant. Residents can build one of the pre-approved plans on their property, saving time and design costs while adding much-needed housing to the community.
Nadthachai leads the program, managing the design and coordinating City staff with structural, energy, and fire sprinkler consultants.
Auburn, CA · 36 homes · Preliminary design
Auburn Cohousing
An affordable, intergenerational community of 36 homes and a common building on 4.6 acres, developed with Placer County as part of its Government Center master plan. At least 40% of the homes will be affordable to low-income households.
Vancouver, BC · 30 homes · Preliminary design
East Van Cohousing
A 30-home urban community in a single apartment building on about a quarter acre, showing how cohousing works at city density. Residents shaped the design through four workshops and share a common house with a large kitchen, a workshop, and play areas.
Portugal Cove, NL · 51 homes · In permitting
Killick Ecovillage (Cohousing NL)
The first cohousing community in Newfoundland and Labrador: a multigenerational ecovillage on 57 acres of heritage farmland with two common houses, on-site food production, and a Mutual Home Ownership model that keeps monthly fees affordable.
Port Townsend, WA · 8 homes · In development
Newt Crossing Cohousing
Eight homes and a common house on a 17-acre wooded site, clustered along a pedestrian lane that keeps 88% of the land as open woodland. Most of the new homes are single-story to support aging in place.
Nadthachai’s Housing Work & Awards
3rd Place: Urbanarium’s Decoding Density Competition (2024)
With teammates Xian Chris Li, Elitsa Vutova, and Liam Lautze (as PAC Lab), Nadthachai placed third out of 85 international entries for Cul-de-sac Nouveau. The proposal opens a suburban cul-de-sac with a pedestrian laneway framed by two cohousing communities, using a community land trust, a housing co-op, and cross-laminated timber to keep homes affordable and low-carbon.
1st Prize: Vancouver Affordable Housing Challenge (2022)
With Xian Chris Li and Elitsa Vutova, Nadthachai won Buildner’s international competition for Laneway Village, which turns Vancouver’s underused back lanes into cohousing communities with shared and small commercial spaces. The jury called it “a smart expansion of an already existing and approved policy.”
Domum Scholarship: AIA Los Angeles’s 2x8 (2020)
Nadthachai’s student project Joy Cluster won one of three top-tier Domum Scholarships in AIA Los Angeles’s statewide 2x8 program. Developed at Cal Poly’s LA Metro Program, it breaks a large mixed-use building into clusters of modular units connected by shared in-between spaces.