Structural Insulated Panels (SIPs for short) are a highly durable type of building material with excellent thermal performance. The compact, flat panels are made by sandwiching together different, composite materials to create a product that is robust and air-tight, thus providing superior insulation. Being lightweight, Structural Insulated Panels can be put together to create the walls, floor and roof of a modular building off-site before being transported to their final location.


Why use SIPs over more traditional types of building material? Here are some of the advantages of building with Structural Insulated Panels:

  • Thermal performance. The composition of a SIP means that it is exceptionally air-tight, providing excellent insulation to your building. Rooms built using SIPs will feel warmer and take less energy to heat.
  • Compact and lightweight. Structural Insulated Panels are thin and compact, so they take up less space than regular walls. That means you can get the most out of the space available to you, freeing up extra room within your interior that would normally be taken up by thicker walls.
  • Environmentally friendly. The superior insulation properties of Structural Insulated Panels mean that they are an excellent choice for the environment. With virtually no heat lost through the air-tight panels, the use of SIPs makes for an energy efficient building that minimises waste.
  • Resistant to damp and cold. Buildings made from timber or other traditional materials may be susceptible to problems such as compression shrinkage (where wood shrinks in humid conditions) and cold bridging (where a poorly insulated part of the building lets in the cold and increases the likelihood of condensation). Buildings constructed from Structural Insulated Panels are immune to these issues.
  • Highly suited to off-site construction. In contrast to more traditional building materials, Structural Insulated Panels can be put together off-site. Because they are lightweight they can be transported after the main construction work has already been done, and installed at their intended site only when the building is almost complete. This is a big advantage for projects that would otherwise be delayed due to adverse weather (as the off-site construction can take place indoors) and for sites where disruption from building work needs to be kept to a minimum.


Structural Insulated Panels are often used in the construction of modular buildings because they offer all the advantages mentioned above:

  • Often prefabricated off-site, modular buildings require a lightweight material that can be easily transported.
  • SIP panels also allow modular buildings to be taken apart and moved again as required.
  • As standalone structures that are susceptible to the elements, modular buildings also need to be constructed with durable and well insulated materials.

At Green Modular, all of our buildings are made using SIPs. Find out more about our sustainable and efficient modular building materials.


What are SIPs made of? Structural Insulated Panels consist of two outer layers of panel board (the bread in the sandwich) that encase insulating foam, either made from closed-cell polyurethane (PU) foam or expanded polystyrene (EPS). In the UK, the panel board that encases the foam is always made from OSB/3, which meets British building standards for structural integrity.

SIPs are available in a variety of sizes to suit all building projects, from commercial spaces to modular buildings for schools.