1. System Overview

The G-Tech Residential Building System, developed by Guocai (Beijing) Academy of Building Science Co., Ltd., is a fully prefabricated and all-bolted steel structure solution designed for residential applications.

It integrates the main steel frame, external and internal wall systems, roofing, flooring, windows, and doors into a unified modular package.

All components are factory-produced and assembled on site without welding, allowing fast and precise construction by non-skilled workers.

The system complies with the Australian National Construction Code (NCC) and key AS/NZS standards, providing a safe, durable, and cost-effective building method for detached houses, townhouses, and granny flats.

2. Key Advantages

• All-bolted connections eliminate welding, ensuring consistent quality and reducing labor dependence.
• Fast installation: for a 249 m² single-storey residence, the main structure can be erected by three workers within one week.
• Highly prefabricated: structure, enclosure, and finishing systems are fully modular and manufactured off-site.
• Superior adaptability: applicable to low-rise buildings up to three storeys, with structural spans up to 12 m.
• Excellent performance: wind and earthquake design based on AS 1170; steel design in accordance with AS 4100.
• Cost efficiency: reduced construction time, minimized errors, and simplified logistics lead to significant cost savings.
• Sustainability and comfort: inorganic materials resist termites, minimize noise, and enhance thermal performance.

3. Structural System

Main Frame: galvanized rectangular hollow-section steel columns and beams, connected via adjustable inner sleeves and high-strength bolts, achieving zero on-site welding.

Connection Performance: verified through ABAQUS static hysteresis analysis; beam-to-column joints behave as rigid connections.

Roof Truss: designed in FrameCAD per AS 1170 load standards, using C89 × 41 × 11.5 × 0.75 mm cold-formed steel; factory-punched holes and self-tapping screws ensure precision.

Foundation: composed of individual footings and tie beams (300 × 600 mm, total height 600 mm). Prefabricated reinforcement cages improve accuracy and reduce site work.

Applicability: suitable for various Australian foundation types, with optional prefabricated foundation packages.

4. Envelope Systems

External Walls

Two standard options are provided:

• AAC panel or block wall – solid, durable, and compliant with Australian Standards.
• 150 mm composite wall panels – fixed horizontally with screw battens for rapid installation.

Internal Walls

Available as AAC panels, lightweight concrete blocks, or sandwich panels — each offering quick installation, good insulation, and smooth finishes.

Roof System

• Multi-layer composite metal roof panels integrating insulation, moisture-proof membranes, and protective coatings.
• Materials meet AS 1397 and wind-load design follows AS 1170.2.
• Installed with self-tapping screws to ensure secure and weather-tight connections.

5. Windows and Doors

All window and door systems are designed and tested to comply with AS 2047, AS 1288, AS 2208, and AS 4666.

Performance and cost tiers include:

6. Performance and Construction Efficiency

The G-Tech system reduces total construction time by over 40% compared to traditional timber or light-steel houses, while improving precision, durability, and occupant comfort.

7. Standards and Compliance

Design Standards:

Material Standards:

• Steel: AS 1163, AS 1391, AS 1544.2
• Bolts: AS 4291.1
• Roofing: AS 1397
• Insulation: AS 4859
• Fire Safety: AS 1530.1
• Windows and Glazing: AS 2047 / AS 1288 / AS 2208 / AS 4666

8. Patents and Technical Achievements

Over 10 invention and utility model patents granted in China, including beam-column sleeve joints, self-locking column bases, and roof-to-wall transition joints.

International patents: two in Australia, two in New Zealand, and one in the United States.

Participated in drafting several national technical standards:

• Technical Code for Low-Rise Fully Prefabricated Rectangular Tube Structures
• Bolted Rectangular Tube Joint Drawing Collection
• Green Prefabricated Wall Technology Code

Supported by leading institutions such as Tsinghua University, China Academy of Building Research, and Wuhan University of Science and Technology.

9. Application Scenarios

• Detached Houses: open layouts, minimal internal barriers, adaptable to various architectural styles.
• Townhouses: efficient, cost-effective, and modular solution optimizing land use and build time.
• Granny Flats: compact, flexible, and quick to assemble — ideal for guest, rental, or multi-generation living.