Feasibility study on the renovation and upgrading of steel structure buildings in Xinjiang

1. Research background and significance

With the deepening of urbanization and the growing demand for renewal of existing buildings, Xinjiang steel structure buildings have shown significant advantages in areas such as industrial heritage revitalization, commercial space renovation, and old factory upgrading due to their lightweight, high-strength, excellent seismic performance, and strong sustainability. According to the "China Steel Structure Industry Development Report (2023)", the proportion of existing steel structure buildings in my country has reached 23%, and more than 15% of these buildings face problems such as functional aging, excessive energy consumption, or insufficient safety performance. Xinjiang Steel Structure Editor said that under this background, carrying out feasibility studies on the transformation and upgrading of steel structure buildings not only meets the development requirements of green buildings under the "double carbon" goal, but also enables efficient use of building space and reshaping of value through technological innovation.

2. Technical feasibility analysis

(1) Structural safety assessment technology

The core premise of steel structure modification is to ensure structural safety. Through the combination of drone laser scanning and BIM technology, the three-dimensional model of the building can be reconstructed with an error controlled within ±3mm. Stress wave tomography technology is used for non-destructive testing of steel components, which can quickly identify welding defects, rust levels and fatigue cracks. The editor of Xinjiang Steel Structure Manufacturer said that in an old steel plant renovation project, engineers used ANSYS finite element software to simulate load changes and found that the maximum stress value of the original structure under the new sandwich load reached 210MPa, which is close to the yield strength of Q235 steel. Therefore, carbon fiber cloth reinforcement technology was used to increase the bearing capacity of the components, increasing the structural safety factor to more than 1.5 times.

(2) Modular transformation and space reconstruction technology

The detachability of Xinjiang steel structures provides convenience for modular transformation. Prefabricated steel components connected by bolts can achieve an on-site assembly rate of more than 70%, shortening the construction period by 40% compared with traditional concrete structures. Taking the renovation of an industrial park in Beijing as an example, the design team transformed the original single-story factory building into a three-story LOFT office space by increasing or decreasing the spacing between steel columns and replacing lightweight enclosure materials. The floor area ratio was increased from 0.8 to 2.5, while retaining the industrial aesthetic characteristics of the steel structure trusses. In addition, the application of the new cold-formed thin-walled steel system has reduced the self-weight of the reconstructed building by 30%, significantly reduced the foundation load, and indirectly reduced the cost of foundation reinforcement.

(3) Green energy saving and intelligent upgrading technology

In terms of energy-saving renovation, the use of a "vacuum insulation panel + airgel felt" composite insulation system can reduce the heat transfer coefficient of steel structure buildings from 1.5W/(㎡·K) to 0.3W/(㎡·K), reaching passive building standards; the combination of integrated photovoltaic (BIPV) technology and steel structure roofs can achieve an annual power generation of 150kWh/㎡, meeting 30% of the building's electricity demand.The editor of Xinjiang steel structure manufacturer saidIntelligent upgrades are reflected in the implantation of the Internet of Things (IoT) system. By installing fiber optic sensors at key nodes of steel components, temperature deformation and vibration data are monitored in real time, and connected to the cloud platform to achieve predictive maintenance. One case shows that this technology can reduce building operation and maintenance costs by 25%.

3. Economic feasibility analysis

(1) Comparison of renovation costs

Taking the renovation of a 1,000㎡ steel structure factory building as an example, the traditional demolition and reconstruction cost is about 2,500 yuan/㎡, while the comprehensive cost of renovation and upgrading (including structural reinforcement, functional update, and equipment replacement) is about 1,800 yuan/㎡, a cost reduction of 28%. If the "EPC + PPP" model is used to introduce social capital, the government only needs to bear 30% of the start-up capital, and the balance of funds can be achieved through rental income and carbon trading income. In addition, some cities provide tax exemptions for industrial heritage renovation projects (such as property taxes being halved for five years), further increasing the return on investment.

(2) Investment return cycle

The editor of Xinjiang steel structure manufacturer saidDue to the improved functions of the renovated steel structure building, the rental premium can reach 2-3 times that of the original building. For example, after an old shipyard in Shanghai was transformed into a cultural and creative park, the rent increased from 1.5 yuan/(㎡·day) to 4.5 yuan/(㎡·day), and the investment payback period was shortened to 8 years. If combined with the urban renewal policy to obtain floor area ratio incentives, the return period can be further compressed to less than 5 years through the sales income achieved by increasing the construction area.

(3) Long-term economic benefits

The whole life cycle cost advantage of steel structure buildings is significant. Data shows that its maintenance cost is only 50% of that of concrete buildings, and it can achieve an 80% resource reuse rate through material recycling within a 30-year use cycle, which is in line with the concept of circular economy. In addition, renovation projects can usually shorten the construction period by 6-8 months, and the cash flow generated by being put into operation in advance also brings hidden benefits to the project.

4. Policy and environmental feasibility

At the local level, the "14th Five-Year Plan for Building Energy Saving and Green Building Development Plan" clearly states that "promoting the green transformation of existing buildings and giving priority to the renewal of steel structure buildings" and setting up special subsidy funds; at the local level, places such as Shenzhen and Hangzhou have refined the floor area ratio reward policy, allowing renovation projects to increase the operating area by 20% of the original building area. In terms of environment, steel structure renovation can reduce construction waste by more than 85% and reduce carbon emissions by 60% compared to new buildings. One project obtained LEED Platinum certification through renovation, which enhanced the brand's green value.

5. Risks and Countermeasures

(1) Technical risks

The editor of Xinjiang steel structure manufacturer saidFatigue damage of steel welded joints is a major hidden danger, and UT (ultrasonic flaw detection) detection coverage is required; for historically protected buildings, structural modifications must be demonstrated by experts to avoid damaging the authenticity, and reversible reinforcement technology (such as bolted connections instead of welding) can be used.

(2) Market risk

If the functional positioning after renovation is inconsistent with the regional planning, it may lead to difficulties in attracting investment. Countermeasures include conducting early market research and adopting a "customized transformation" model, such as reserving load conditions for clean workshops based on the needs of biopharmaceutical companies; introducing industrial operators to intervene in the design process in advance to ensure space adaptability.

(3) Policy risks

Adjustments in local government planning may affect the approval of renovation projects. It is recommended to use a "flexible planning" strategy to reserve multi-functional conversion interfaces in the design, such as the quick switching function between office space and exhibition space, to enhance the project's ability to withstand policy fluctuations.

6. Conclusion and suggestions

The renovation and upgrading of steel structure buildings technically have mature structural optimization, green energy saving and intelligent solutions, and economically show the characteristics of controllable costs and stable returns, and are in line with the strategic orientation of urban renewal and carbon neutrality.The editor of Xinjiang steel structure manufacturer saidIt is recommended to focus on three tasks in the future: first, establish a technical standard system for steel structure building renovation, unify inspection and evaluation methods and reinforcement design specifications; second, promote the "design-construction-operation and maintenance" integrated (DBO) model to improve the efficiency of full-cycle project management; third, increase investment in research and development of new materials (such as high-performance steel, bio-based composite materials) to further reduce renovation costs. Through systematic promotion, steel structure building renovation is expected to become an important engine for promoting high-quality development of the construction industry.