Analysis methods for the cost of prefabricated building

1. Analyze the design costs of the prefabricated building

    Nowadays, the design of prefabricated buildings mainly adopts the design method equivalent to cast-in-place, and then the components are separated according to the assembly and production requirements of a component. This method has low design efficiency and poor collaborative performance. For prefabricated components, the production drawings of components should be compatible with the construction installation and structure disciplines. The design contents of embedded parts, fittings, holes and nodes of prefabricated components must be fully reflected in the design drawings . Because the design depth and content are increased, the design cost of prefabricated buildings will be 20~40 RMB/m2 higher than that of traditional cast-in-place structures.

2. Analysis of component logistics cost of prefabricated buildings

    For cast-in-place buildings, the logistics cost of materials will be considered as a component of the material cost, but for prefabricated buildings, a large number of prefabricated components must be directly transported from the component factory to the assembly site .  For example, if the transportation distance is 60 km, the transportation cost of prefabricated components will be about 100 to 150 RMB/m3, so the relevant management departments should not ignore the cost of component logistics .

    Firstly , storage charge . For traditional cast-in-place buildings, relevant staff will pour at the construction site. After the maintenance work is completed, the building entity can be formed directly, which does not need to occupy the storage site . However, for fabricated components, after the completion of production, the component factory needs to have a special site to maintain and store the components, and needs to be equipped with professional personnel for management. After the maintenance work is completed, it is also necessary to find an appropriate site for storage, which increases the storage costs .

    Secondly , transportation cost. For prefabricated buildings, finished components will be protected during transportation due to their vulnerability to damage, large volume, irregular shape, etc . The distribution of component plants is uneven and the configuration is insufficient, which increases the distance of component transportation and also increases the transportation cost at the same time .

3. Analyze production cost of components

    The component factory will deliver the prefabricated components to the construction site for assembly and installation after maintain mass production . Nowadays, because the scale of prefabricated buildings is relatively small and government support is not strong, the production cost of prefabricated components mainly includes labor costs, raw materials and equipment depreciation costs.