66	CONSTRUCTION ENGINEERING
66.1	Structural mechanics. Constructional planning
66.2	Geotechnics. Earth-moving
66.3	House building
66.32	Building components
66.33	Building materials. Construction works
66.34	HVAC and plumbing. Electrical installation
66.341	Heating
66.35	Outhouses and annexes
66.36	Room acoustics
66.4	Building maintenance
66.6	Road building
66.7	Hydraulic engineering
66.9	Environmental municipal services
66.93	Water and waste water services
66.94	Waste disposal. Recycling