Introduction: What are SIPs?
Structural Insulated Panels (SIPs) are a modern construction method that uses offsite manufacturing to create panelized kits. These panels form a thermally efficient and airtight building envelope, reducing heat transfer and improving energy efficiency.
Fabric-First Approach
SIPs align with the fabric-first philosophy, which focuses on maximizing the performance of the building’s materials before adding mechanical or electrical systems. This approach reduces capital and operational costs, boosts energy performance, and lowers carbon emissions. With stricter building regulations, focusing on U-values (heat transfer rates through materials) is critical, and SIPs meet these requirements effectively.
Ventilation Considerations
Since SIPs create an airtight envelope, proper ventilation strategies become essential to maintain healthy indoor air quality. This typically involves incorporating systems like mechanical ventilation with heat recovery (MVHR) to balance energy efficiency with fresh air circulation.
Why It Matters
SIP panel construction helps optimise energy performance, but addressing ventilation ensures a comfortable, sustainable living environment.
“Build Tight, Ventilate Right”
This mantra emphasises achieving thermal efficiency by preventing unintentional ventilation (draughts) and designing an adequate, purposeful ventilation system. Draughts occur due to uncontrolled airflow through gaps, cracks, material joints, and pipe or cable penetrations in a building’s fabric. These unwanted air leaks lead to increased heating demands, as they cool the internal air temperature. By focusing on airtight construction and well-planned ventilation, homes can maintain energy efficiency and indoor comfort.
SIPs are renowned for thermal efficiency
SIPs are renowned for creating some of the most thermally efficient and airtight buildings worldwide, performing exceptionally in both sub-zero and hot climates. With heating efficiency a key priority for many homeowners, SIPs stand out due to their high insulation and airtightness, resulting in remarkably low U-values compared to traditional construction methods.
For example, Kingspan’s TEK Building System boasts air leakage levels as low as 0.08 air changes per hour at normal pressures. This is achieved through its OSB/3 facing and proprietary jointing system, which significantly reduces heat loss, lowers heating demands, and ensures compliance with energy performance regulations.
While SIPs minimize heating and cooling loads, maintaining a consistent and comfortable indoor temperature, their airtightness can limit natural ventilation and affect air quality. Proper ventilation systems are essential to address this challenge and ensure a healthy indoor environment.
Installing a Mechanical Ventilation with Heat Recovery (MVHR) system
Installing a Mechanical Ventilation with Heat Recovery (MVHR) system in a SIPs-built home is an ideal solution for ventilating airtight spaces while supplying clean, filtered fresh air. MVHR systems extract stale air and distribute fresh air throughout the building, removing carbon dioxide, humidity, cooking odours, pollutants, and off-gassing to maintain a comfortable and healthy indoor environment. Without adequate ventilation, moisture and harmful contaminants can become trapped, potentially damaging the property and impacting the health of its occupants.
The MVHR system’s heat recovery process works by capturing heat from the extracted stale air and transferring it to the incoming fresh air via a heat exchanger and duct network. This process retains a consistent indoor temperature while ensuring a steady supply of fresh air. Impressively, up to 95% of the heat from the extracted air can be recovered, significantly reducing heating costs.
To maximize the efficiency of an MVHR system, the building must be well-insulated and as airtight as possible. Kingspan recommends mechanical ventilation for properties designed to achieve an air-leakage rate of 3 m³/hour/m² at 50 Pa or better. The combination of Kingspan TEK SIPs and an MVHR system creates a draught-free, airtight, and energy-efficient home. In fact, this setup can eliminate the need for traditional central heating systems, such as those relying on radiators. For some, adding a wood-burning stove might be a desirable aesthetic feature, but it is no longer a necessity for maintaining a warm, comfortable home.
Ensure that your SIP’s design takes into account the integration of MVHR
We advise speaking with your architect about possible options for an MVHR system as soon as you start working with them. Who will integrate the MVHR system with other technologies in the designs. This should be complete prior tothe building regulation drawings beingsubmitted and approved.
To ensure that your SIP construction takes into account the integration of MVHR or any other eco-technologies, it is crucial that you discuss this with your SIP provider. To ensure proper floor joist alignment and early identification of any other technical issues, the location of the MVHR duct must be determined at the start of the procedure.
For homes being developed to Passivhaus standards, SIPs are the ideal construction approach. Complementary eco-technology, like an MVHR system, is frequently integrated. An MVHR system is regarded as a low-carbon choice that, when combined with other environmentally friendly building techniques like structural insulated panels, could help you achieve Passivhaus certification. Always talk to your architect if you want to construct to Passivhaus standards; they will explain the steps and requirements.
