Acronyms here. Acronyms there. Acronyms pretty much everywhere. It seems like you never have to go far in the world before you stumble across a sequence of letters that seemingly make little sense without knowledge of the topic. Very often though, they are important and need to be understood fully in order to grasp and talk confidently about industry specifics. So, if you are in the construction industry, and someone is asking what’s your SAP? How good is your U-value? Or have you done a SBEM calculation? You will have a heads up on what some of those mean and their importance.

This month’s Celotex Technical Twitter Takeover looked to point you in the right direction giving you an insight in to some of the various different acronyms and key terms that are present in the construction industry. From R-values to BREEAM, this brief blog runs through some of those terms that you might not have discovered yet.

What is a U-value (W/m²K)?

A U-value is a measure of heat loss through a floor, wall or roof and is measured in Watts per metre squared per Kelvin. The higher the U-value the lower the thermal performance of the building envelope. A lower U-value improves the thermal performance of a building, which is good for the house owner and great for the environment. For a quick and easy U-value calculator, sign up free of charge to our Celotex Member’s Area and create your calculations for a project.

What is an R-value (m²K/W)?

An R-value is a measure of how well a material insulates at a given thickness and is expressed in m² Kelvin per Watt. The higher the R-value the better! Celotex has a broad range of products which achieve very good thermal performances and provide the opportunity to gain higher R-values.

What is a Lambda value (W/mK)?

A measure of how well a material conducts heat, expressed as Watts per metre Kelvin. It is represented by the Greek letter Lambda and is an important consideration in construction. A lower lambda = a slower conduction of heat.

What about BIM? What does that stand for?

BIM stands for ‘Building Information Modelling’. This is the digital representation of a building’s design process and materials. Celotex’ entire product range is available as BIM objects in all major software formats and are IFC compatible. These can be viewed in our BIM Lounge. Available free of charge in all major formats (e.g. Autodesk Revit, Bentley etc.) plus IFC compatible. Register as a Celotex member or login now to download your BIM objects.

What does BREEAM stand for?

BREEAM stands for ‘Building Research Establishment Environmental Assessment Methodology’. It is the world’s leading design and assessment method for sustainable buildings. For more information on BREEAM, visit the website – .

What does SAP stand for?

SAP stands for ‘Standard Assessment Procedure’ and measures the energy usage and carbon emissions of a dwelling. SAP takes in to consideration:

  • Building materials
  • Insulation values
  • Thermal bridging
  • Air tightness
  • Ventilation
  • Heating and lighting
  • Use of renewable energy technologyCelotex Energy Assessments

Celotex Energy Assessments (CEA) provide a comprehensive range of energy efficiency and sustainability services including SAP calculations. Celotex Energy Assessments perform SAP calculations, working to ensure that the project is signed off by Building Control.

What does SBEM stand for?

SBEM stands for ‘Simplified Building Energy Model’ and measures the energy usage and carbon emissions of buildings other than dwellings. New buildings and extensions in excess of 100m² and more than 25% of the original building require an SBEM.

What does PIR stand for?

A vast majority of people in the industry are familiar with ‘PIR’ but only a small minority will know what it stands for. PIR stands for ‘polyisocyanurate’ and is rigid PIR foam used to make high performance insulation materials such as that of Celotex.

For more information on PIR, here is a blog explaining 10 advantages of PIR insulation.

What does CfSH stand for?

CfSH stands for Code for Sustainable Homes. This is a method for assessing and rating the sustainability of a dwelling in England, Wales and Northern Island. Some new homes built in the UK require assessment against the Code for Sustainable Homes (CfSH).The Code is a standard for sustainable house-building, based on nine key areas:

  • Energy/CO2
  • Water
  • Materials
  • Surface water run-off
  • Waste
  • Pollution
  • Health and well-being
  • Management
  • Ecology

If your project is at the design stage and is required to meet a Code for Sustainable Homes standard, Celotex Energy Assessments can assess it in order to ensure it is on the right track. However, we would recommend assessing the project throughout the build in order to achieve a Code certificate upon completion without unnecessary delay or additional costs. We are able to provide this service regardless of the project’s size or complexity.

What is a Psi value (W/mK)?

A Psi value is the measurement of heat loss through a junction in a building such as a corner or around a window. It is represented by the Greek letter Psi. Improving your Psi value can be a great way to eliminate the need for other costly eco-bolt ons such as solar panels and could potentially reduce the cost of new builds and improve thermal performance.

Celotex Insulation Technical Takeover - Key Terms and Acronyms

Thanks to those that tuned in to the November Technical Twitter Takeover and be sure to join us again next month for the final Technical Twitter Takeover of 2014 #AskCelotex.

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