Light is a key element in the ArtHouse mixed-use student housing facility for the Pacific Northwest College of Art in Portland, Ore. The owner, developer, and architect wanted to take full advantage of daylight to create a sustainable, low-energy building that also inspires creativity and provides comfort. Residential corridors are built to the edge of the building, splitting apart the building mass to bring light into the hallways at every level. Polished concrete floors maximize the use of daylight, and reduce electrical usage for the entire facility.

The project faced many challenges including very hard concrete slabs. Concrete in Portland, like much of the Pacific Northwest, tends to be extremely hard, making it difficult to grind and polish. The concrete mix used for this project included a 50/50 mixture of crushed aggregate and round river rock from local resources to give the floor its natural “Pacific Northwest” characteristics.

To properly grind and polish ArtHouse’s hard concrete, “I adjusted my head speed to 10 and the disc speed to 7, and set both to rotate in the same direction. I ripped the crown off that slab and never cross-hatched once.” explains Dennis Meyer of Concrete Reflection.

Meyer used the Husqvarna Hiperfloor system to create the bonded-abrasive diamond-polished concrete floors. The contractor used a latex-based grout system during the transitional diamond pass, bonding concrete dust from the slab into the surface imperfections to create a natural color that matches the floor. After densification, the floor was refined to a reflective level between 20-16µin (micro inches) to create a rich, reflective floor that could make use of the daylight pouring in from the interior courtyard and street-side windows.

The project transformed Portland’s downtown Pearl District. Within a year, citywide demand for large-aggregate, polished concrete floors has increased significantly.

The student housing project was also honored with several awards from the City of Portland and the local AIA chapter. Art House also received LEED Silver certification from the U.S. Green Building Council.