Since 1910, National Building Services & Maintenance, Inc. cover a wide spectrum of businesses and industries: office buildings, medical facilities and clinics, industrial plants, oil refineries, retail centers, financial institutions, and computer facilities. Window Cleaning: Both Hi-Rise And Low-Rise Buildings. One-Time Or Scheduled Contracts. Janitorial Service,Window Cleaning,Flood Restoration,Carpet Cleaning,Drapery Cleaning,Upholstery Cleaning,Pressure Washing,Construction Cleanup,Emergency Situation Cleanup Both Hi & Low Rise Window Cleaning!