SIPs Panels 101

Structural insulated panels, or SIPs for short, are an innovative building material that can be used to build walls, roofs and floors in homes. SIPs are incredibly versatile building materials that can be used in various applications and shapes while providing homeowners with an affordable way to build custom homes.

SIPs are gaining momentum in the Australian construction industry and provide many benefits, including energy efficiency, versatility and ease of installation. SIPs panels come in various thicknesses, rigidities and finishing options, so homeowners can choose SIPs to give their homes a unique touch. SIPs panels can be used for interior and exterior applications.

This article will discuss what structural insulated panelling is and the benefits and disadvantages of SIPs.

What Are Structural Insulated Panels (SIPs)?

Initially developed in the USA in the 1930s, the main idea behind SIPs is to combine a structural element and an insulating element in a single unit so that there’s no need for a separate structural element or an air gap. SIPs are sheet materials consisting of rigid foam insulation sandwiched between two structural facings of oriented strand board (OSB). The OSB panels are bonded together using waterproof adhesive in addition to screws, staples or nails.

Expanded polystyrene (EPS) and extruded polystyrene (XPS) are two common insulation materials used in SIP construction. SIPs panels come in various thicknesses and rigidities and can be used for both interior and exterior applications. SIPS can be installed as a stand-alone wall, roof or floor system or attached to an existing structure.

Typically, the two primary materials used are an EPS core for the insulation and OSB for the panels.

Expanded Polystyrene (EPS)

EPS is a recyclable thermoplastic material that has many applications. It can be used to make cups, packaging materials, and insulation for homes. Expanded polystyrene is made by blowing up tiny beads of polystyrene into larger shapes like sheets or blocks. The result is lightweight yet durable foam with high insulating properties, making it an excellent choice for home insulation.

Oriented Strand Board (OSB)

Oriented strand board, also known as OSB, is a type of engineered wood panel. It is made from small strands or fibres oriented in the same direction and glued together to form a sheet. OSB is an alternative to plywood and particleboard. Some benefits include being economical, easy to work with, can be shaped for any size project, has good strength properties and is resistant to rot and splitting.

Other possibilities include polyurethane insulated panels, which have a greater R-Value when compared to EPS and are more resilient to fire or water damage. As a result, Polyurethane insulated panels are more expensive than Expanded Polystyrene. Compressed Straw is another option – it offers lower R-Values but is the most eco-friendly choice.

Structural Insulated Panels – Pros and Cons

Building with SIPs panels offers several benefits, including better energy efficiency, excellent fire resistance, cost-effectiveness, and strength. SIPs also help to protect against condensation by providing more insulation than traditional materials like plywood or OSB for sheathing. Additionally, because they are pre-cut in factories to exact specifications that fit together like puzzle pieces, structural insulated panels can be installed faster than other types of insulation. The downsides include higher upfront costs when compared to other methods. They also require precise cutting and installation, which requires specialised skill sets and sound design know-how.

The Benefits of Using SIPs

SIPs are a great alternative to traditional building materials because they offer many benefits. They provide better insulation and energy efficiency than other materials, can be installed quickly and easily, and the individual components of SIPs are recyclable, so it is environmentally friendly. So let’s explore the advantages a little further.

Energy Efficient

SIPs can insulate homes very well because the panels are dense, heavy and rigid. Once installed, the panels provide high thermal resistance and energy efficiency. The rigid structure prevents air infiltration and, therefore, helps to keep the weather out and the warm air inside the house. When the weather gets hot, SIPs panels provide a cool indoor environment. They have been shown to be 50% more energy-efficient than timber framing methods.


Because wood products (including recycled sawdust) are the primary material for SIPs, these panels are often seen as being both environmentally friendly and sustainable in their construction. In addition, as it is prefabricated offsite minimal waste is created. As we have already discussed, it is also energy-efficient, saving you money and reducing greenhouse gas emissions, helping the environment.

Health Benefits

SIPs contain no VOCs (volatile organic compounds), which can be an irritant to some people and a potential health risk. In addition, SIPS are cavity-free, preventing condensation from building up and causing mould growth.


Due to their innovative design, SIPs are incredibly robust. Because of the composite structure of the EPS foam core and the OSB outer panels, the combination of both elements makes them stronger as a whole. SIPS are much more durable than a traditional wood frame; they are estimated to be up to six times stronger.

Fast Installation

The installation is much faster as much of the time-consuming onsite construction steps are reduced when opting for SIPs. The panels are prefabricated offsite to exact specifications with precision and quality, saving time and labour onsite. With the factory cut pieces fitting together perfectly, especially when using a tongue and groove technique standard with SIPs, installation can be quick and efficient.

A SIPs construction project will be a lot faster than that of one with a timber frame. It is estimated that SIPs will save weeks of job site time with a two-storey house taking around 12 days to erect one after being prefabricated offsite. In contrast, a timber frame build can take three to four weeks. Using SIPs, the project will be a lot less costly, saving on labour, site insurance, plant hire, scaffolding and other job site expenses.

Versatile Usage

One of the most significant advantages of SIPs is that they are manufactured to exact specifications. SIPs can be constructed to accommodate nearly any building design, and the options for customisation are virtually unlimited.

SIPs can be used in everything from flooring to roofing to walls, and they can also be used for different structures, such as storage buildings, garden sheds, pool cabanas and garages. If you want to create a room divider, SIPs panels make it incredibly easy to do so.

More Roof Space

When SIPs are used in conjunction with roofing, they can eliminate the need for roof trusses, which is a significant advantage. This provides the option for additional living space under the roof, for instance, turning a three-bedroom house into four bedrooms. This conversion of roof space can increase the value of your property considerably.

Sound Proof

SIPs can also be used as soundproofing for residential homes or commercial buildings due to their sound deadening qualities. SIPs offer excellent sound insulation qualities, so they can help reduce noise pollution, which is perfect if you have a family that likes loud music or has noisy pets.

The Disadvantages of Using SIPs

The pros of SIPs certainly outweigh the cons, but they do come with some disadvantages.

Can’t Be Used in Certain Areas

Some locations are not suitable for SIPs construction. It is not recommended to use SIPs on sites in flood zones or below ground; a masonry construction would be preferable in this situation. However, nothing prevents you from constructing a hybrid structure with a concrete ground floor and Structural Insulated Panels for the upper levels of the building.

Not Easy to Find Competent Contractors

SIPs are still relatively new in Australia, and as a result, finding qualified contractors with relevant experience might be difficult. In many circumstances, there are lengthy wait times for skilled professionals.

Sip panels view from the top


While termites and other pests don’t feed on the EPS core, and though uncommon, it has been known for insects to nest in it. It is always a good idea to have the panels treated with insecticide and ensure that you have termite prevention methods in place to protect against damage to your home.

History of SIPs Usage

SIPS were first created in 1935 by the Forest Products Laboratory in Madison, Wisconsin. They developed prototype panels consisting of hardboard sheathing, insulation, and plywood. Test homes were built using the wall panels, and when taken down and examined thirty years later, it was discovered that they had maintained their initial strength.

The Usonian residences designed by Frank Lloyd Wright in the 1930s and 1940s were constructed using a type of SIP. However, in 1952, the first foam-filled SIP was developed, and the idea truly came into being.

Since then, technological advances such as CAD (Computer Aided Design) and CAM (Computer Aided Manufacturing), as well as CNC machining, has infused even more life into the process.

In Conclusion

SIPs can offer many benefits to homeowners and contractors alike. However, before deciding whether or not to use structural insulated panels as part of your next building project, you should take the time to consider all of the pros and cons associated with this type of construction material. We hope this article has given you some insights to make an informed decision about what is best for your project.


How much do SIPs cost?

SIPs come prefabricated in various sizes and thicknesses and can range from a few hundred dollars for a small SIPs panel to thousands of dollars if large enough to completely cover a lot. The costs of building with SIPs depends on dimensions, make, brand and grade, as well as labour costs associated with installation.

Where can SIPs be used?

SIPs have been used successfully on both commercial and residential properties. SIPs construction is also suitable for most climates.

What are R-values?

The R-value is a metric used to quantify the thermal resistance of insulation. It measures how well heat passes through an object and therefore offers a measure of its insulating quality. The higher the R-value, the greater the insulation provided by that material or product and the more energy efficient it is. SIPs with higher R-values can lead to significant savings on your bills by reducing your energy use.

What are SIPs made of?

SIPs consist of a rigid foam core that contains expanded polystyrene (EPS) or extruded polystyrene (XPS), enclosed in a continuous layer of oriented strand board (OSB).