Optimising SIPs for your design - is it essential?
Designing a home with Structural Insulated Panels (SIPs) offers a unique opportunity to combine innovative architecture with energy efficiency and streamlined construction. SIPs offer numerous benefits for most designs, including excellent thermal performance, strength, and lower upfront carbon. However, careful consideration of the panel layout can further enhance these advantages, making the construction process more streamlined and cost-effective.
Here’s what you need to know to optimize your SIP design without sacrificing architectural flair.
Panel Sizes and Efficiency
The standard width of a Formance SIP is 1220mm. To optimize material use, you can design around these full, half, and third panel sizes (1220mm, 600mm, and 400mm). Doing so can reduce waste and lead to significant cost efficiencies, especially on large-scale projects or multi-unit builds.
However, for bespoke residential projects where design flexibility is paramount, adhering strictly to these sizes can sometimes limit creative freedom. In such cases, the form and function of the building should always take precedence over panel optimization. That said, it’s worth considering panel sizes in your early design stages to see if some degree of optimization can still be achieved without compromising your vision.
Designing Multi-Units or Repeat Typologies
In projects where uniformity is key, such as in multi-unit housing developments or repeat typology designs, the benefits of optimizing for panel sizes become more pronounced. By designing with full, half, and third panels, you can reduce offcuts and labour time, which is especially beneficial when scaling the same design across multiple units.
For these types of builds, it’s worth working with Formance early in the design process to ensure the design is properly optimized to suit.
Openings and Infill Panels
Positioning doors and windows can also significantly affect how efficiently SIPs are used. If an opening is placed in such a way that it leaves an awkward space smaller than a full panel, infill panels (which are less than 180mm) may be needed. These smaller infill panels are typically formed from oriented strand board (OSB) skins over timber studs, which can lead to increased thermal bridging and reduced insulation efficiency.
To avoid unnecessary infill panels, aim to align window and door openings to panel breaks where possible. For instance, standard full panel widths like 1220mm can serve as a guide when positioning openings to ensure minimal material wastage. Also to note, panels over 180mm wide include insulated cores, so it’s best to keep panel sections above 180mm where possible.
Set-Out and Tolerances
Formance panels come with a 3mm construction tolerance gap to allow for site discrepancies and tolerances with other building products i.e. steel or concrete. The panels are generally accurate to the millimetre, so this gap allows for any onsite adjustments, and although it seems small, it adds up over a wall length. It’s important to allow for this if you are doing your design based on a 1220mm grid, as it should really be 1223mm. It’s not essential to do a grid for your house design, and the Formance detailing team is experienced in getting any design to work with SIPs.
Roof Panel Orientation
Lastly, it’s vital to be clear about your roof panel orientattion during the design phase. Properly aligning roof panels can prevent unnecessary cuts or adjustments on-site, ensuring that spans are accurate and efficient from the outset. By working with the natural dimensions of your SIPs, you'll reduce both installation time and potential material wastage.
Our stock panel lengths are 2740mm, 3660mm and 7200mm, so it’s a good idea to consider this when designing your roof. Also important for the roof is the detailing of steel or non-SIP structural elements (i.e. ridge beams). Keeping them inside the dwelling is always the recommended approach due to the ease of construction and reduction in thermal bridging.
Designing With Flexibility and Efficiency in Mind
While it's important to prioritize material efficiency when working with any product, the beauty of SIPs is that it can be specified on a wide range of designs. By focusing on optimizing panel layouts where it makes sense—especially in multi-unit or repeat builds—you can reduce waste, save time, and lower costs. However, in bespoke residential designs, always prioritize the form and function of the building.
Contact Formance to learn more!