Timber Innovations’ Ian McCarthy explains why the interest in SIPs as a modern method of construction continues to grow fast
The UK is seeing a rapidly increasing enthusiasm among self-builders and others in the construction sector to opt for structural insulated panels (SIPs) as their primary build method. SIPs are another “modern” method of construction that have actually been around for some time – in fact, SIPs are popular in the United States, where they have been in use for over half a century.
An advanced method of construction, SIPs offer excellent thermal performance and lightweight structural strength. SIPs use less timber than traditional timber frame and are one of the most economical and eco-friendly forms
SIPs are used in walls and roofs for residential, commercial and educational sites, providing ecologically friendly and energy efficient buildings. They are usually used in conjunction with metal web joists for upper floor systems.
The structural panels are made in a continuous production process by expanding the insulation material between the two outside facings of 15 mm oriented strand board (OSB) – it is this ‘autohesively’ bonded sandwich that gives this type of SIP panel its exceptional levels of performance and robustness.
SIPs can be custom designed for each building. For example, Timber Innovations’ SIPs are produced at an in-house factory following the bespoke design and desire of customers. The end result is a building that is extremely strong, energy efficient and cost-effective.
Speed of construction
One of the most popular reasons why customers choose timber frame is the swiftness of construction, and SIP homes go up much faster than traditionally timber-framed buildings. This in turn can relate to cost, which is of course an important factor in any self-build project. Customers appreciate the budgetary benefits to timber frame and SIPs – the swiftness of the building’s erection means you reduce both construction and labour costs, an understandably popular consideration.
SIPs can also offer much more versatility than other construction materials, allowing a multitude of possibilities beyond the conventional for those still involved in the design stage. One of the spin offs of this is that it offers, for instance, more habitable living space in the finished project.
For example, sloping roof panels create an open space that can maximise all opportunities for full utilisation. Where once conventional roof carpentry to create the roof space left a ‘spider’s web’ of posts and beams, SIPs offer the capability to span from ridge to eaves with, at most, one intervening horizontal beam.
This means that SIPs are proving particularly popular when it comes to creating ‘rooms in the roof’; for instance in three storey townhouses, or to simply add extra room in a one or two-storey building.
Another important consideration is that SIPs are one of the most environmentally friendly methods of construction and make a significant environmental impact by reducing energy use and greenhouse gas emissions. A SIPs building provides continuous insulation, is extremely airtight, allows for better control over indoor air quality and helps save natural resources.
When compared to older construction methods, SIPs produce buildings that are generally more energy efficient, stronger, quieter and more airtight. Less air leakage means fewer drafts, fewer noise penetrations and significantly lower energy bills, thus a reduction in CO2 emissions.
Some of the other benefits which can be gained for self-build projects by choosing SIPs include:
- extra floor space;
- doors, windows etc., are always be pre-framed with the structure;
- environmental sustainability;
- a robust and solid feel;
- the use of less timber than conventional timber frame construction;
- excellent resale potential.
A recent self-build project involving the use of SIPs panels proved to be a particularly unique challenge, as the client required a swift build process that had the correct specifications to be erected on top of their existing basement.
It was extremely important that this construction was quick to create a weather-tight shell over the existing level, as well as ensuring that the structure was designed in a way – with the correct materials specified – to guarantee the basement could effectively support the building.
The client chose to use SIP panels that could meet the erection time requirements, and the lightweight construction limited the need for extra reinforcements on the pre-laid foundations – meaning significant cost savings and achieving an improved U-value for the property of 0.18.
The prefabricated system allowed the frame to be designed accurately and co-ordinated exactly with the basement design prior to arrival onsite. The precise engineering eliminated any discrepancies that could have occurred onsite. Additional features included the integration of an MVHR system – due to the use of SIPs, great insulation properties and inherently good airtightness values were achieved.
As the advantages of SIPs become increasingly more persuasive to many, some companies are taking further measures to assist those interested; for example, SIPsInnovations is a specialist division of our firm, which was created to meet the increased demand for the energy efficient and environmentally friendly construction system.
At the last count, 75 per cent of self- builders were choosing timber frame as their primary method of construction, and the enthusiasm is reflected throughout the construction industry. SIPs are no longer the ‘new kid on the self-build block’. SIPs, for many, are the future!
Ian McCarthy is business development manager at Timber Innovations