by It is recommended to pay attention to the first sister of the project.
Since the implementation of precast buildings, the penetration rate has not been high, and not many enterprises have joined the Bureau.
The main reason is that the comprehensive cost of precast buildings at this stage has been higher than that of cast-in-place.
The cost advantage of precast buildings mainly lies in reducing labor costs and speeding up the construction period, but it may not be able to catch up with the cost increment brought by other aspects for the time being, because the cast-in-situ PC components have more production and transportation links, which is much higher than the cost.
Take the material cost as an example.
The concrete content of the cast structure is generally about 3% – 5% more than that of the cast-in-situ structure.
In addition, there are faults in the communication between the design link, factory manufacturing link and on-site installation link, resulting in information asymmetry, construction quality problems and rework, resulting in material waste and construction delay.
To improve the cost advantage of precast buildings, on the one hand, we should catch up with the cost disadvantage through other cost advantages, on the other hand, we should also find suitable solutions to improve the current cost disadvantage.
In terms of policy, precast buildings have unique support.
While the government proposes to improve the assembly rate, it gives subsidies to enterprises; In the market, with the increase of component factories and professionals, the cost will be reduced accordingly under the scale effect; The enterprise itself also has corresponding measures to reduce the cost of production and transportation.
In the future, precast buildings may have different cost advantages from today.
Let’s look at the details below.
Find out the cost disadvantage.
Due to the high population density and the state-owned land system, the mainstream of precast buildings in China has always been high-rise precast concrete structures.
The main cost comes from the cost of PC components, including production, transportation, marketing, management and so on.
Among them, production and transportation is the cost of cast-in-situ components, and most of the cost increment of PC components also comes from this.
1.
Production cost, material cost and mold cost account for the majority.
First of all, material cost: like cast-in-situ structure, PC components are mainly applied to reinforcement and concrete.
There is no great difference in the unit price of materials, but the amount of PC components is several percentage more than that of cast-in-situ, which opens the overall gap of material cost.
In addition, the industrial chain of precast buildings is mainly the supply of raw materials and equipment – factory production components – real estate development.
In an ideal state, when raw materials and equipment are given to the factory, they can produce PC components that meet the requirements of developers.
When transported to the development site, workers can quickly install them.
However, the reality is often that when the design communicates with the factory, the two sides do not necessarily reach the same understanding.
After the components are produced, the workers may not understand the requirements during installation.
Therefore, it may occur that the communication in the early stage is not deep, or the change in the later stage is not well interactive, resulting in that the components cannot be put into use after production, or the on-site workers do not know the installation needs, resulting in damage to the components, etc.
information asymmetry will often cause construction problems, wasting materials and delaying the construction period.
Just like the traditional construction, if the drawings are unreasonable or the update is not interactive in time, it will also cause problems in the on-site construction.
In addition, mold cost: precast buildings have many requirements for the production of precast components, but now the prefabrication rate is not high, and the molds of precast components must be precise and accurate.
Basically, many are customized products with different specifications, so the molds of PC components need a lot and the reuse rate is low.
This leads to the high cost of equipment in the early stage, but the utilization rate is not high.
On average, the cost of each component is very high.
However, cast-in-situ is different.
Both reinforcement and cement can be prepared on site, and the required equipment and tools can be recycled almost all the time, resulting in a certain cost gap.
2.
PC components rely on transportation, and the cost is not low.
PC components not only need to be transported to the construction site by loading vehicles, but also need to be lifted from the ground to the installation elevation.
The PC components are large and have heavy weight, and the precast buildings are not large-scale, there are few factories, and different components may be scattered in different places, so the horizontal transportation cost is very high, which also requires certain radius requirements between the project and the factory, otherwise the corresponding cost is difficult to load.
The hoisting cost mainly lies in the expensive machinery cost, but the vertical transportation demand of PC components is much larger than that of cast-in-situ components, so the cost is also much higher.
To catch up with the cost disadvantage, we must tap the cost advantage that the existing buildings do not have.
The “timing” of precast buildings is the support of national policies.
1.
The most direct support: subsidies} in recent years, precast buildings have been supported by policies from the national level, and there are different corresponding subsidies in major provinces and cities.
Many cities have incentives for building area, refund of value-added tax immediately, financial incentives in a certain proportion according to the incremental cost, and the practice of giving priority to the production base (Park) of cast building components and project construction land, etc.
this part of the subsidy is enough to offset some cost gaps between cast and cast-in-place..
