Impact of construction scheme optimization on cost
The rationality and advancement of the construction scheme directly affect the project cost. Taking air-conditioning duct fabrication as an example, the factory prefabrication scheme increases material utilization by 15%-20%, reduces labor consumption by 30%-40%, and lowers the comprehensive cost by about 10%-15% compared with on-site manual fabrication. Construction sequencing of main ducts before branch ducts, mains before risers, and large ducts before small ducts can reduce rework losses. Regarding mechanical equipment selection, large-diameter ducts processed on automatic production lines achieve efficiency 5-8 times that of manual fabrication.
On-site management of materials and equipment and loss control
On-site management of materials and equipment directly affects material costs. Material loss rates for MEP works: duct sheet 5%-10%, water pipes 3%-5%, cables 3%-6%, insulation materials 5%-8%. Loss control measures include accurate budgeting, quota-based material requisition, surplus material recovery, and waste sorting. Accurate budgeting calculates material quantities precisely based on construction drawings and BIM models. Quota-based requisition must not exceed 105% of the budgeted quantity. Surplus material recovery allows reuse in subsequent construction of the same specification. Waste sorting involves centralized processing and recovery of scrap copper, scrap steel, etc., to offset costs.
Correlation between construction schedule management and cost
The construction schedule is closely related to the project cost. The construction period of MEP works usually accounts for 50%-60% of the total schedule, and schedule delays will incur additional management fees, equipment rental fees, and labor cost adjustments. Taking the MEP works of a five-star hotel as an example, the daily delay cost is about 25,000-40,000 yuan. Schedule management strategies include preparing progress plans using network planning techniques, shortening the schedule by 15%-20% through the flow-line operation method, and identifying process conflicts in advance through BIM 4D schedule simulation.
On-site measurement of quantities and payment management
On-site measurement of quantities is the basis for process control of project cost. According to Chapter 8 of GB 50500, quantity measurement shall be carried out monthly. The difficulty in MEP works measurement lies in concealed works (embedded sleeves, concealed conduits, ducts above ceilings), which should be photographically recorded before concealment and acceptance certification handled promptly. All measurement results must be signed and confirmed by both the contractor and the supervision engineer as the basis for progress payment. The progress payment ratio is generally 80%-90% of the completed quantities.