Mason Street ADU

Mason Street ADU, designed by Tweto Architecture, occupies a 425-square-foot footprint on a corner lot in Portland’s King neighborhood. The project was designed as a companion to the property’s primary structure, a former grocery store, aiming for a distinct identity within compact dimensions. The exterior is marked by a steeply pitched roof with pronounced overhangs and is clad in simple fiber cement siding for durability. Select wood accents appear in the recessed entry and beneath the eaves, while windows set deep into the facade provide dimensional interest. The ADU’s interior arranges its living and kitchen areas along the south-facing street frontage, optimizing natural light through generous glazing, four skylights, and the vaulted ceiling. The bedroom and bathroom, located at the rear beneath a loft, enjoy added privacy. The loft space offers a flexible bonus area. Polished concrete floors run throughout, and there is a built-in bookcase anchoring the living room’s back wall. The porch features hand-selected, salvaged Douglas Fir. Originally conceived as a residence for an aging parent, the ADU has since adapted to serve as a short-term rental, guest suite, and event space, with long-term plans for owner occupancy.

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