Correct U-value calculation
Best practice principles not only apply to the design and construction of buildings, they are essential to the process in which building products are specified. This is particularly pertinent to U-value calculation and selecting insulation as an effective regulator of heat loss and gain through a building’s walls, floors and roof.
Make Best Practice, Your Aim When It Comes To U-Value Calculation
Certain products may look the same but can vary wildly in respect of U-value compatibility and in-situ performance. For a satisfactory outcome, contractors should have the necessary product knowledge before committing to its installation.
Correct U-value assessment could be the difference between success and failure in terms of building regulations compliance. It is also an enabler to creating homes with an effective thermal envelope, good levels of comfort and cost-effectivity, and lower carbon impacts.
SAP and SBEM calculations, the government’s method of recording the respective energy performance of dwellings and non-dwellings, set the compliance parameters for a building based on its proposed carbon footprint. This takes into account the anticipated thermal performance assessment of key structural elements and is used as part of the calculation to determine the overall energy performance. Data resulting from a thermal performance assessment is used to produce an Energy Performance Certificate (EPC).
Ask the Experts
Early engagement with an expert insulation manufacturer is crucial to the fabric-based composition of walls, floors and roofs to assist with EPC and building regulations compliance. Recticel’s technical team, for example, will carry out U-value calculations on a customer’s behalf based on their specification. This can then be used as evidence that the specification will meet regulation requirements. As a company committed to improving construction standards for a better-built, more sustainable environment, Recticel provides free access to an online U-value calculator, allowing users to complete their own U-value calculation. This excellent digital tool assists users in first look thermal calculations, providing a guide before formal calculations can be carried out by the Technical Team.
There is no room for error at the building design and specification stage, with the same precise professionalism being of upmost importance to a project’s material installation phase. Poor workmanship could result in costly repair work or worse, building demolition. Hence, contractors should take the greatest care to follow a manufacturer’s guidance. This is particularly pertinent to insulation, which must uphold a building’s long-term thermal performance by preventing heat loss and facilitating building regulations compliance.
Elements of a building project are subject to change, with cost being a common cause of material substitution. However, full consideration should be given prior to any substitution, as the money saved could be greatly outweighed by the expense of nullifying the impact of incorrect product specification. Product changes rarely happen in isolation, as amendments often impact other building details, resulting in additional alterations and the potential for project delays. Therefore, it is best practice to outline any proposed product or material changes to a project’s designer.
Installers: Mind the Knowledge Gap
Familiarity breeds success when it comes to building product installation. Contractors have a greater chance of completing the process efficiently if they are better aware of the composition and performance of the products they are handling. Certain products may look the same but can vary wildly in respect of U-value compatibility and in-situ performance. For a satisfactory outcome, contractors should have the necessary product knowledge before committing to its installation. To overcome a gap in product know-how, contacting the manufacturer for specialist training is recommended.
With revised U-value targets introduced via Part L regulation changes to improve building energy efficiency, it has put further focus on a fabric-first approach to construction. Again, this could be another area where training will benefit contractors looking to create the ideal thermal envelope.
In summary, correct U-value calculation is an effective route to a well-insulated building that offers effective heat loss prevention and achieves building regulations compliance.
Vacuum insulation
Are you planning to insulate a terrace, which needs to comply with the required U-value, but you have limited space?
At Recticel Insulation, we are committed to supplying high-quality insulation solutions for flat roofs. This is the reason why we created Deck-VQ - a tailor-made vacuum insulation solution for insulating terraces, where there is limited space.
Deck-VQ gives the opportunity to achieve low U-values within minimal insulation build-up, which is vital in many refurbishment and new build projects where there are structural or planning constraints. To make the installation simple and the most efficient, we are happy to provide a customised installation plan.
Construction law & regulations
Can I get a U-value calculated for my project using Recticel Insulation products?
Absolutely! Please contact our freephone technical helpline on 0800 085 4079 or use our free of charge U-value calculator here.
Energy efficiency
What is the difference between a U-value and an R-value?
U-values take into account all elements of a construction, including thermal bridges. They can only be worked out by calculation. The R-value, or thermal resistance, is a measure of the insulation board on its own, dividing the thickness (in metres) by the thermal conductivity (lambda value, W/m.K). The R-value can be used to compare how different thicknesses of products with different lambda values perform comparatively.