Glass curtain wall refers to the building exterior structure or decorative structure in which the supporting structure system can have a certain displacement capacity relative to the main structure and does not share the role of the main structure. Glass curtain wall is a beautiful and novel method of wall decoration, which is a prominent feature of the era of modernist high-rise buildings.
Composition of engineering cost of glass curtain wall
Composition of curtain wall engineering cost: curtain wall projects are contracted by qualified professional curtain wall design, manufacture and installation companies, which usually include deepening design, factory production, transportation, on-site installation and protection, etc.
The composition of project cost is different from that of general civil structure engineering, which mainly includes the following contents:
(1) Direct engineering cost: including the labor cost, material cost and machinery cost of the curtain wall, in which the material cost mainly includes skeleton (aluminum alloy or steel structure), finishing materials, accessories, sealants, etc., and the direct engineering cost accounts for the largest proportion of the total curtain wall cost.
(2) cost of measures: scaffolding construction fee, hanging blue demolition fee; supporting steel structure on-site assembly and installation of trestle engineering fee; point-supported cable net structure pretension, deformation adjustment, counterweight test fee; large glass plate installation measures Jiangcheng template production confirmation removal fee; finished product protection fee, such as anti-pollution, damage prevention and cleaning fee for glass, aluminum plate, stainless steel, stone slab, etc. Large machinery entry and exit fees, such as supporting steel structure hoisting machinery entry and exit fees; increased costs caused by cross-operation with mechanical and electrical, decoration and other professional construction companies, such as multiple transfer of working face, materials, machinery and tools, reduction of work efficiency, etc.; necessary overtime and rush measures. The cost of secondary or multiple transfer of materials caused by the narrow construction site, the parking fee due to late arrival of materials and equipment at the construction site, the cost of safe and civilized construction, etc.
(3) Management fees, profits and taxes.
(4) deepening design fee: the detailed drawing design of the professional curtain wall design and construction company, the examination and confirmation of the main architectural design unit and the cost of construction detail drawing production.
(5) additional fees for imported materials and equipment: packaging of imported materials and equipment, overseas warehousing and transportation, commodity inspection, customs clearance and local storage, necessary air transportation fees, fees for the use of patented technology, fees increased by any changes in prices, rates and exchange rates.
Therefore, it can be seen that in the cost composition of the glass wall project, the material cost accounts for a large proportion, which can be as high as 70-80%, the labor cost accounts for about 5-10%, the mechanical cost accounts for a very small proportion, and other expenses other than the comprehensive price also account for a large proportion. Especially the glass curtain wall with large scale, complex structure and high difficulty in construction, even as high as 10-20%.
Valuation method of glass curtain wall project
The valuation method of glass curtain wall cost mainly adopts bill of quantities, which is different from other structural engineering costs in that it does not use a set of quotas, but directly determines its cost according to relevant laws and regulations and market prices. and calculate different costs according to different standards, including the direct cost of the project, calculate the combined price of a single project, and according to the category of the project, gather into a list, accumulate into a summary table.
Strictly speaking, the valuation of the bill of quantities is given by the bidder, and the bidder combines the comprehensive unit price of the project according to the bill of quantities. And calculate the cost of partial projects, and then calculate the tax, and finally summarize into the total cost.
The cost composition of the glass wall project:
1. Material costs account for a large proportion, which can be as high as 70-80%.
2. Labor costs account for about 5-10%.
3. The proportion of machinery cost is very small.
4. Other costs also account for a large proportion, especially glass curtain walls with large scale, complex structure and high difficulty in construction, even as high as 10-20%.
Glass curtain wall with open frame, hidden frame and semi-hidden frame
1. Aluminum alloy profiles (20% to 30%).
2. Glass (20% / 30%).
3. Structural adhesive, weathering adhesive (58%).
Point-supported glass curtain wall
1. The cost of steel supporting truss accounts for about 10-20% of the unit price of curtain wall.
2. The cost of glass accounts for about 20% of the price.
3. Stainless steel pull rods and cables and accessories account for about 20%.
4. If the tension rods and cables of large curtain wall projects adopt imported fittings, the connection system accounts for about 10%.
5. The weathering adhesive has little effect on the cost.
The cost of curtain wall in high-rise buildings is higher than that of multi-storey buildings of the same type
1. The cost of the unit curtain wall is 715% higher than that of the frame curtain wall.
2. The cost of the open frame is less than that of the hidden frame, which can reach 10%. 20%.
3. The cost of the semi-hidden frame is about 5% less than that of the hidden frame.
4. When the height of the glass curtain wall is about 10m, the unit price of the hanging type is mostly lower than that of the point support type.
5. The unit price of the all-glass curtain wall with a height of more than 12m is mostly higher than that of the point-supported type, in which the hanging all-glass curtain wall supported by the glass rib joint has the highest unit price, which is more than 3000 yuan / m2, and the glass plate is thick and the unit price is very high.
6. The cost of glass curtain wall per square meter is mostly about 1000-3000 yuan.
Technically, the cost of curtain wall increases with the increase of height, wind load and grid size.
Whether there is a frame or a point-supported curtain wall, the wind load generally plays a controlling role. The increase of wind load will increase the section size and wall thickness of aluminum profile, and increase the section height, wall thickness and cable diameter of steel truss. At the same time, the thickness of the glass plate is increased.
The variety and specification of glass has the greatest influence on the cost, so we should adopt more regular standard flat glass as far as possible, and if arc-shaped hot-bending glass is used, the project cost will be increased. Similarly, the use of larger unit size or thicker glass will also increase the project cost.
The above is the introduction of how to calculate the cost of glass curtain wall. if you want to know more about glass curtain wall, please feel free to contact us.
Post time: Jun-02-2022