Prefabricated Housing Design Specifications and Standards
The specifications and standards for prefabricated housing design cover aspects such as structural safety, seismic performance, sound and thermal insulation, service life, fire protection regulations, material usage, design principles, and other design requirements, as detailed below:
Structural Safety: Prefabricated components must meet stringent load standards. The design live load for typical residential prefabricated floor slabs should be no less than 200 kilograms per square meter, with dead loads including the self-weight of the slab and the weight of the facing layer. Ordinary prefabricated slabs are suitable for spans of 3-6 meters; spans exceeding this require special calculations and structural reinforcement, with a minimum placement length of 10 centimeters and ensuring effective connections. The dimensions, reinforcement, and connection methods of main structural components must comply with seismic requirements.
Seismic Performance: According to the 'Code for Seismic Design of Buildings', prefabricated structures must pass integrity checks. Node connection areas must withstand repeated loads under design earthquake conditions and must be equipped with energy dissipation devices or redundant restraint systems.
Sound and Thermal Insulation: The airborne sound insulation level for party walls should be no less than 50 decibels, and the impact sound pressure level for floors should be controlled below 65 decibels, typically achieved through the use of elastic pads or floating floor structures. Appropriate thermal insulation materials should be selected to enhance thermal insulation effects.
Service Life: The design service life for prefabricated residences in ordinary climate zones is 50 years, with structural inspections required every 10 years; this period is shortened by 20-30% in coastal areas with high salt spray or northern regions with frequent freeze-thaw cycles. New regulations in 2024 require a minimum thickness of 30 millimeters for anti-corrosion coatings in exposed environments.
Fire Protection Regulations: The fire resistance limits for prefabricated concrete components are 3 hours for load-bearing walls, 2 hours for non-load-bearing walls, and 1.5 hours for floors; steel structures require fireproof coatings or fireproof boards. High-risk fire areas (such as kitchens and bathrooms) need additional fire separation zones and the use of fireproof materials.
Material Usage: The concrete strength grade should be no less than C20, and the tensile strength of steel bars should be no less than 335 MPa. Wall panels should be selected from stable materials such as rock wool boards and polystyrene boards. The production of cement prefabricated components must follow specifications to ensure dimensional accuracy, strength, and durability, with sand, gravel, steel bars, and other materials meeting national standards.
Design Principles: Prefabricated rural houses should be functionally modern, structurally safe, cost-effective, environmentally friendly, and harmonious in style, integrating climate, topography, and traditional architectural features to meet modern living needs. Concrete prefabricated slab houses should be optimized in design to reduce costs and extend lifespan, complying with regulations and ensuring construction quality and environmental safety.
Other Design Requirements: Prefabricated rural houses should respect farmers' needs, reflect regional characteristics, consider aging-friendly designs (such as barrier-free ramps), and have layouts conducive to sunlight and ventilation, with simple and regular shapes. Functional spaces should include bedrooms, dining rooms, storage rooms, etc., achieving separation of dynamic and static areas. The roofs of concrete prefabricated slab houses should be reliably waterproof, and sound insulation designs should use efficient materials.
