THERMAL PERFORMANCE – THE HOT TOPIC

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With the UK’s drive to improve the thermal performance of its buildings, it is an ideal time for merchants to talk to customers about key products. Here, Richard Price, Technical Director at Catnic explains the positive impact of thermally broken lintels against the backdrop of changing legislation.

When it comes to sourcing information and products to help them do their job well, builders’ merchants are a crucial point of reference for trade professionals. As such, counter staff have to be aware of the industry drivers, legislation and be equipped with the relevant product knowledge.  

 For example, merchants should be aware that the Future Homes Standard will require new build properties to be futureproofed with low carbon heating and world-leading levels of energy efficiency by 2025.

 To support this there will be changes to Part L of the Building Regulations in 2020, to improve the energy efficiency of new homes but to also encourage trade professionals, and more complex supply chains to work to higher specifications. Two options have been put forward for the amendments:

 Option 1 - ‘Future Homes Fabric.’ This would be a 20% reduction in CO2 from new dwellings, compared to the current standards.

 Option 2 - Fabric Plus Technology.’ This would be a 31% reduction in CO2 from new dwellings, compared to the current standards. This option is likely to encourage the use of low-carbon heating and/or renewables.

This will be in readiness for the introduction of a further uplift in requirements and targets in 2025.

 Trade professionals will now need to consider these regulations, however big or small the project, when it comes to making well–informed product choices. When it comes to the fabric of the building, modern innovations by leading manufacturers mean that even the most common structural elements can provide excellent thermal efficiencies – and in line with recommended regulation changes and best practice.

 A fabric first approach

 Heat always flows from a warm area to a cold one, and in the case of buildings, this means warm air can flow from inside a property to outside. Changes in the building fabric at junctions such as corners, eaves or a window head allow heat to flow. This is because there might be a reduction in the insulation or material passing through the insulation layer – what is more commonly known as a thermal bridge.

 As a result of this thermal bridge, more heat will be flowing out of the building meaning more energy is required to maintain internal temperatures. This translates into higher energy costs and CO2 emissions.

 In line with the updated Building Regulations Part L, the thermal performance of each building component needs to be carefully considered in terms of their contribution to heat loss calculations, with all elements considered holistically to ensure they work together in a ‘fabric first’ approach. With Part L now placing more emphasis on thermal bridging as a way of reducing heat loss, a product which can make significant difference, is the lintel structural elements.

 Give it a lintel thought

 The consultation for Part L has also laid out new proposed minimum standards for fabric performance in new dwellings. These are as follows:

  • External walls – 0.26 W/m2.k
  • Door 1.6 W/m2.k
  • Windows 1.6 W/m2.k

 With these improved figures in mind, it is even more important that thermal bridging at junctions in the building is kept to an absolute minimum. The Catnic range of Thermally Broken Lintels feature a unique composite design to provide a complete thermal break between the inner and outer leaf of a cavity wall. Independently verified by the British Board of Agreement (BBA) and the Building Research Establishment (BRE), lintels within the range provide a linear energy transmittance psi value of 0.02 to 0.05 W/mK.   

Obviously, achieving thermal performance should never be at the cost of structural performance. This is why Catnic’s range of thermally broken lintels provide the same working loads as our standard lintels, so there is no need for reassessment of loads over lintels – making it a far simpler, hassle-free conversion.

 There are a multitude of other factors that need to be considered when it comes to making an informed product choice; meeting required standards, considering whether a separate damp course is needed, durability, corrosion resistance and fire safety.

 With all the complexities of current regulations and performance requirements, and the proposed changes, there is clearly an extensive amount of information for merchants to keep up to date with. This is an immense undertaking, given the wide range of areas merchants already need to be well-versed on. 

Seek specialist support

 Therefore, knowledge and resources from trusted suppliers should be called upon wherever possible. Free of charge services, such as our free Lintel Advance Scheduling System (CLASS) can prove incredibly beneficial to merchants and trade customers. Given each project is unique, our specialist team uses the project drawings to determine wall construction, lintel lengths and required loads and ensure that the correct lintels are ordered.

 CLASS also has the added advantage of helping merchants to upsell - scheduling additional products that are required for the same project, for example soffit cladding, metre box lintels or PVC arch centres.

 With challenging targets in place for the UK to reduce its carbon emissions and more to come, addressing thermal performance is now top of the agenda. Merchants need to work with trade professionals to help them address this in the building fabric. The good news is that the product portfolio and support from manufacturers is in place, so by working together we can help build it better for the future.

 For more information on Catnic’s Thermally Broken Lintel range and other services, please visit www.catnic.com/products/lintel...