HSG s full-service window cleaning operation is doing its part to keep the Los Angeles skyline beautiful. The company specializes in commercial building maintenance and surface restoration, including window cleaning, demineralization, caulking, waterproofing, high-pressure cleaning, metal and curtain wall restoration, scratch removal and bird control. Some of HSG s accounts include the 52-story Arco Plaza, the 35-story Constellation Place, the 52-story 777 Tower and Wilshire Courtyard, which consists of six separate buildings. Founded in 1980 as a one-man operation, HSG is a certified member of the Minority Business Enterprise.