The history of Structurally Insulated Panels

SIP Structure

The history of Structurally Insulated Panels  | In the age of technology, and the increasing use of modern methods of construction, SIPs are achieving mainstream status. Structurally Insulated Panels (or SIPs) offer many advantages over traditional building methods, including being lightweight, thermally efficient and much more.

What are SIPs?

SIPs feature a timber facing, typically OSB, bonded either side of an insulated core. This highly insulated design can allow them to achieve exceptional thermal performance. For example, 172mm SIPs with a rigid urethane insulation core can achieve U-values of 0.16 W/m2.K. or better without the need for additional insulation. Their factory engineered joints can also help to significantly limit air-leakage from the building envelope.

The panels can be cut to each building’s unique specifications whilst still in the factory. This provides designers with a high degree of creative freedom and helps to keep waste and adjustments to a minimum on-site. The panels slot together snugly like pieces in a jigsaw, and their lightweight design means they can be quickly installed by a small team of operatives. In addition, once the building shell is formed and a breather membrane applied, the panels are temporarily weatherproof, allowing internal fit-out to begin.

Whilst SIPs are a relatively recent addition to the UK market, they have a long and well-established history, beginning in the USA in the 1930’s.


1935: The FPL began experimenting with what they described as ‘stress-skin’ or ‘structural sandwich’ panels in Madison, Wisconsin. The initial panels were formed from a honeycombed paper core with a number of facing materials including plywood, Douglas-fir, and aluminium.

1940: Famed architect Frank Lloyd Wright used structural insulated panels in some of his affordable Usonian Houses built throughout the 1930’s and 1940’s.

1952: In 1952, architect Alden B. Dow developed a new panel design using a polystyrene foam insulation core manufactured by his family’s company, Dow Chemicals, and in the process creating the first true Structural Insulated Panel. Unlike its sandwich panel predecessors, the first Dow SIP homes were observed to be draft free, easy to heat in winter and easy to keep cool in the summer.

1973: Following the rapid increase in energy prices after the 1973 oil crisis, the construction method firmly took root, first in the US and Canada, and then across Europe.

1980: Oriented Strand Board (OSB), an engineered structural panel was developed resulting in the production of SIPs as we know them today.

1990: The development of the Passivhaus Standard in the early 1990s further supported this growth, with the fast, simple erection process and outstanding fabric performance making SIPs a natural choice for the fabric-based standard.

Today: With their exceptional strength and energy saving properties, SIPs continue to provide a high tech solution for residential and low rise non-residential buildings. Advances in computer aided design and manufacturing allow SIPs to be produced with amazing accuracy to deliver flat, straight and true walls.


  1. The high strength to weight ratio of SIP Panels allows large sections of your building to be fitted at once, speeding up the time required on site for erection. 
  2. The offsite fabrication reduces waste and also helps reduce embodied and transport energy.
  3. SIP insulation exceeds the current Building Regulation requirements on its own.  The foam insulation has an Ozone Depletion Potential (ODP) rating of zero and has a low Global Warming Potential (GWP).
  4. Through their strength and ease of connection, SIPs offer the designer more versatility than other construction materials, allowing possibilities beyond the conventional, such as sloping roof panels creating an open space that when utilised, properly maximises any building plot.

“SIPs buildings are generally more energy efficient, stronger, quieter and more airtight than older technologies.  Less air leakage means less drafts, fewer noise penetrations and significantly lower energy bills, thus a reduction in CO2 emissions,” concludes Chris.

Professional Builder Magazine