Renovation of water supplying pipes; repair of water supplying pipes; repair of hot-water supplying pipes; installation of water purification apparatus on water supplying pipes; construction, namely, plumbing services; construction consultancy; maintenance of installations for power supply, air conditioning, sanitary, and fire extinguishing; operation and maintenance of building equipment; repair and maintenance of fire alarms and fire-fighting equipments; repair and maintenance of air conditioners for industrial purposes; repair and maintenance of burners; repair and maintenance of boilers; repair and maintenance of pumps; repair and maintenance of freezing machines and apparatus for industrial purposes; repair and maintenance of reservoirs; repair and maintenance of electric washing machines for industrial purposes; repair and maintenance of vehicle washing installations; repair and maintenance of power-driven floor cleaning machines; repair and maintenance of water supplying and drainage pipes; repair and maintenance of water pollution control equipment; repair and maintenance of water purifying apparatus; repair and maintenance of waste compacting machines and apparatus; repair and maintenance of waste crushing machines and apparatus; repair and maintenance of gas water heaters; repair and maintenance of non-electric cooking heaters for household purposes; repair and maintenance of cooking pots and pans; repair and maintenance of bath fittings; repair of toilet stool units with a washing water squirts; repair of tatami mats; chimney sweeping; cleaning of building exterior surfaces; window cleaning; carpet and rug cleaning; floor polishing; cleaning of water supplying pipes; cleaning of drainage pipes; reservoirs cleaning; septic tank cleaning; bathtub and bath boiler cleaning; street cleaning