37 Building construction services; asphalting, bricklaying, renovation and restoration of buildings; carpentry, masonry, refurbishment and retrofitting of buildings; excavation services, namely, cable laying, drainage, dredging, and earthmoving; repair, installation and maintenance services in respect of vehicles, elevators and escalators, electrical and mechanical plants, industrial machineries, air conditioners; repair, installation and maintenance of electricity, heating, ventilation, air conditioning, refrigeration, plumbing, solid waste disposal, fire services, cabling and ducting systems and equipment, alarm or surveillance systems and all mechanical and electrical works within a building; repair, installation and maintenance services relating to telecommunications and communications apparatus, electrical apparatus, office automation equipment, data processing equipment, audio, video and data recording and reproducing apparatus, broadcasting apparatus, calculating machines, computers, computer hardware, computer accessories and peripherals; installation of information technology cabling network and fibre optic backbone in buildings, computer apparatus and networking installations; installation of data processing apparatus, computers or communication apparatus; maintenance of data processing apparatus, computers or communication apparatus