Das Chapin Design: ADU Design, Consultation, and Build Services
Das Chapin Design offers a range of design and construction-related services, with a particular focus on Accessory Dwelling Units (ADUs). Working in partnership with ADU Design & Build, LLC., the firm provides full-service general contracting alongside its core design and consultation work. Their services are oriented toward thoughtful, efficient use of space — whether that means a new detached ADU, a garage conversion, or a basement remodel.
The practice specializes in intimate, well-considered spaces — environments that reflect how people actually live. The design approach centers on understanding how clients relate to their immediate surroundings and helping translate personal ideas into functional, livable results.
ADU Services: Detached, Garage Conversion, and Basement
Accessory dwelling units are a core focus of Das Chapin Design. The firm works across three primary ADU types:
- Detached ADU builder services — New standalone structures up to 800 square feet, designed from the ground up to suit the client's aesthetic, budget, and lifestyle needs. This option allows for the most design flexibility, though it is generally more costly than a conversion.
- Garage conversion contractor services — Converting an existing garage into a livable space can be a cost-effective and resource-efficient solution. Many of these projects have been designed for families looking to house adult children or aging parents nearby, while still maintaining a degree of separation. Garage conversions can also serve as rental units or allow homeowners to move into the ADU while renting out the main house.
- Basement conversion ADU services — Basement ADUs are among the more economical ways to add value to a home and generate rental income. They are required to be separated from the main living area for fire and smoke safety, and typically include noise reduction measures. Basement units also tend to be energy efficient — easier to heat in winter and naturally cooler in summer.
The Oregon DEQ recognizes that renovating existing structures is among the most energy-efficient approaches to housing. Das Chapin Design's garage and basement conversion work aligns with that principle, making use of what's already there rather than building entirely new.
Construction Consultation, Permit Support, and General Contracting
Beyond design, Das Chapin Design offers construction consultation for clients who want to act as their own contractor or simply need help understanding the building process. With hands-on construction experience spanning nearly four decades — including work with straw bale, log, post and beam, standard frame, and steel construction — the firm brings practical knowledge rather than purely theoretical guidance. Das Chapin has held contractor licenses in Massachusetts and Oregon.
Consultation services include help with new construction decisions, interpreting subcontractor language, and understanding what's required to complete a project from start to finish. For those who want to be more involved and potentially reduce costs, the firm can assist in managing subcontractors and guiding the process.
Permit support is also available for clients navigating Portland's building department. From straightforward bathroom remodels to new detached ADU applications, Das Chapin Design can help move through the permit process more efficiently.
For full general contracting, Das Chapin Design works alongside Justin Chapin and Trevor Stewart of ADU Design and Build, LLC. This design-and-build model integrates the contractor into the process from the beginning, working alongside the designer and client to address budget and design considerations as they arise — rather than the back-and-forth typical of the traditional design-then-bid approach.
In addition to ADU work, the firm also handles remodeling projects such as attic and basement conversions, kitchen redesigns, bathroom additions, and dormers or additions to expand existing living space.
