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Portland, OR

type: prefab modular/ADU

status: unbuilt

In 2009, M.O.Daby Design was commissioned to design and develop a system for a collection of factory built (or "prefab") modular dwellings. The design program was for the structures to comply with the current City of Portland zoning code requirements for Accessory Dwelling Units (or ADU's).  The code dictated a maximum 800 square feet, and for the exterior elements (roof pitch, cladding materials, window proportions, roof eaves, etc.) to match that of the primary dwelling on the proposed property.

Our system design is a flexible catalog of modules that can be assembled into multiple layouts with a variety of roof shapes, and exterior cladding to match almost any Portland home while allowing the owner to dictate the space relationships and number of rooms.

Assembled areas range from 240 to 768 square feet of interior space, but can be larger with infinite number of modules in the case that the system is used for structures not needing to conform to the Portland zoning code.

Modules were designed to be built of industry standard building materials in the controlled environment of a factory by human craftsmen using simple jigs and tools. 

Quick and minimal on-site assembly and preparation was a key consideration of the system. 

At a maximum of 12 feet wide & 11 feet tall, the modules are simple to transport to the site.


Design: Matthew O. Daby - M.O.Daby Design

Structural engineer: Hayden Engineers

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