Structural Insulated Panels Design (SIP)

Download Case Study

About the Project

The project involved mixed construction with internal load bearing Rammed Earth Walls, external load bearing Structural Insulated Panels (SIPs) walls utilising foam insulating core and OSB strand board skins with a Tridek roofing system.


Methodologies & Technologies

In this case the proposed footing system needed Intrax Consulting Engineers to consider the requirements for both SIP walls and the varying types of walls construction which required specific design considerations including the potential of differential movement and the effects of that movement on the materials above.

In addition, the connection design required a combination of traditional timber frame roofing for the suspended ceiling sections and specific details for the connection of Tridek roofing to the SIP walls & the Rammed earth walls.


System used

Intrax Consulting Engineers designed the dwelling utilising SIPS panels for the external walls combined with Rammed earth walls & Tridek Roofing panels. These panels together played a large part in achieving this energy efficient design. Rammed earth walls included superior thermal mass, temperature and noise control, strength and durability, low maintenance, fire proofing, load bearing and pest deterrence, as well as the beauty and pleasure of building with a natural and environmentally sound material.

This house has also been oriented optimally to the north with the Tridek roof at the appropriate angle and will use virtually no energy for heating and cooling.

The Challenge

Open plan living with full height sliding doors & windows provided a design challenge in engineering to ensure the overall stability of the structure in particular, as the structure sat in the top-third zone of a steep sloping hill. As SIPs panels have a structural limitation regarding the in-plane shear capacities, steel portal frames were integrated into the SIP system, which maintained the design aesthetics and remained consistent with the
architect’s design intent for the structure.

For the performance requirements of earth buildings, the structure was designed to resist the forces and actions for which it was intended and had an acceptably low probability of failure. It was designed to be able to withstand deterioration due to natural weathering, insect attack, and general use that can be reasonably expected during its intended life, without undue maintenance.



  • Assembly & installation was fast and efficient with factory manufactured pre-cut wall & roof panels.
  • Prefinished colorbond Tridek Roofing system reduced the amount of structural roof framing and bracing normally required. High thermal values, good acoustic values, low maintenance, BCA Group 1 fire rating and ongoing energy cost savings.
  • Less labour and trades were required on site, and there was significantly less site wastage and landfill.
  • This project utilising SIP- Panel wall systemTridek roofing & rammed earth walls was designed by keeping energy efficiency in mind and affordable housing products will have a place in the future of residential housing design.

Project Details
  • Categories



    Yarra Valley, VIC


    Solar Solutions Design


    Hunter Constructions

Intrax has a culture of leadership, innovation, respect, performance and understanding.