It sounds like you’re referring to the use of steel frames and trusses in the construction of modular homes in Sydney, Australia. Using steel for framing in construction has become increasingly popular due to several advantages it offers over traditional materials like wood.

Here are some reasons why Aussie might have moved to steel framing for modular homes:

1. Strength and Durability: Steel is known for its strength and durability. It can withstand harsh weather conditions, such as strong winds and earthquakes, making it a reliable choice for construction in various regions.
2. Termite Resistance: Unlike wood, steel is not susceptible to termite infestations. This is a significant advantage in regions where termites are a common issue, such as in Australia.
3. Precision and Consistency: Steel framing can be manufactured with high precision, ensuring consistent quality. This is particularly important in modular construction, where components need to fit together seamlessly for efficient assembly.
4. Lightweight: While steel is strong, it is also lightweight compared to traditional building materials. This can make transportation and on-site handling more manageable, especially in modular construction where components are often prefabricated off-site and then assembled on location.
5. Design Flexibility: Steel framing allows for greater design flexibility. It can be used to create open and spacious interiors without the need for as many load-bearing walls, providing architects and homeowners with more options in terms of layout and design.
6. Environmentally Friendly: Steel is recyclable, making it an environmentally friendly choice. Using recycled steel in construction helps reduce the demand for new raw materials and minimizes the environmental impact of the building process.
7. Speed of Construction: Steel framing can speed up the construction process. The use of prefabricated steel components in modular construction allows for faster assembly on-site, reducing overall construction time.
8. Fire Resistance: Steel is non-combustible and does not contribute to the spread of fire. This can be an essential factor in regions where fire safety is a concern.

It’s worth noting that the choice of construction materials depends on various factors, including local building codes, climate conditions, and project requirements. If Aussie has adopted steel framing for modular homes, it suggests a recognition of the benefits that steel offers in terms of strength, durability, and efficiency in the construction process..