Jinhua Prefabricated Slab Old Houses

The renovation and handling of old prefabricated slab houses in Jinhua need to be comprehensively judged based on the condition of the houses, the wishes of the owners, and policy conditions, mainly involving three paths: demolition, original-site reconstruction, and renovation and repair.

I. House Condition and Demolition Needs

Prefabricated slab buildings constructed before 2000 have prominent structural aging issues and are most in need of priority demolition. Such houses generally have internal hazards such as floor slab cracking, water leakage, and electrical wire aging. The renovation of old residential areas can only improve the appearance or infrastructure and cannot solve structural safety problems. For example, a brick-concrete structure tube building built in the 1980s in the urban area of Jinhua was recently demolished due to the aging of the prefabricated floor slab and the load-bearing wall's joint force system. The construction team needed to focus on handling issues such as the demolition sequence of non-frame load-bearing walls, dust and vibration control caused by insufficient spacing between adjacent buildings, and the professional disposal of old gas pipelines.

II. Conditions and Challenges of Original-Site Reconstruction

Original-site reconstruction needs to meet dual conditions:

1. House Standards: It is only for C-grade (partially structurally damaged and with safety hazards) or D-grade (whole dilapidated buildings) dilapidated houses. There are more than 500 such dilapidated old houses in the urban area of Jinhua, accounting for 1.4%, and most houses do not meet the demolition standards. The judgment basis includes early construction years, prefabricated slab structures, structural hazards such as wall cracking or floor slab subsidence, and non-complete residential features (without independent kitchens and bathrooms).
2. Owner Consent: Most cities require the consent of at least two-thirds of the owners, while Hangzhou and Shaoxing require 100% consent. Reasons for opposition include the elderly's unwillingness to move, some residents' inability to afford reconstruction costs, and tenants' concerns about rental losses. For example, in the demolition of the above-mentioned tube building, 12 households failed to reach an agreement due to special reasons, and a compensation plan was finally determined through third-party mediation.

III. Classification and Handling of Renovation and Repair

There are about 40 similar tube buildings in Jinhua, which are divided into three categories according to their building conditions:

1. Structurally Sound: Carry out complete set renovation, adding independent kitchens and bathrooms and optimizing pipeline layouts.
2. Moderately Damaged: Implement reinforcement and repair, repair cracks, replace aging electrical wires, and improve living safety.
3. Severely Aged: Include them in the demolition plan. After reconstruction, plan composite functional spaces (such as community commerce + small-sized residential units) and retain public green spaces and cultural symbols (such as the original tube building's pitched roof elements).

IV. Enlightenment from Typical Cases

In the above-mentioned tube building demolition case, the construction party protected rights and interests through historical building assessments, 3D modeling archiving, and notarization of cracks in surrounding buildings. They adopted a layered and segmented demolition method and a three-dimensional dust reduction system to reduce impacts, with a building waste classification and recycling rate of over 90%. The resettlement plan took into account market-oriented housing purchases, property rights exchanges, and transitional housing, and resolved disputes through multiple rounds of reviews by professional evaluation agencies, providing replicable experience for similar projects.