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Tetris Thermal Performance
What is a U-value?
The measure of heat loss through the fabric of a building is expressed as a U-value with limiting values set out in the Building Regulations.
Determining the U-value of the Floor
- Calculate the internal perimeter in metres of the external walls (P)
- Calculate the internal area in metres of the floor (A)
- Calculate the P/A ratio
- Use the graphs to select the thickness and type of TETRiS required to achieve the desired U-value
Building Regulations – Approved Document L
The Building Regulations set out requirements for specific aspects of building design and construction. Regulation 26 of the building regulations states that “Where a building is erected, it shall not exceed the target CO2 emission rate for the building…”, and Schedule 1 – Part L Conservation of fuel and power states that provision for conservation of fuel and power shall be made by limiting heat gain and losses and providing building service which are efficient, have effective controls and are properly commissioned and that information is provided so that the building can be operated efficiently.
Achieving Part L 2021
All new homes must produce 31% less carbon emissions than the old 2013 Part L Regulations. New homes will be assessed under a new Standard Assessement Proceedure (SAP) called SAP10. Builders are encouraged to meet notional dwelling targets for energy efficiency which are measured in u-values. The minimum u-value for floors is set at 0.13w/m2K. Note; this is the minimum therefore if the u-value of another element within the building is poor, then the floor u-value may need to be improved to a lower value. Full guidance of this can be given from SAP Assessors or by visiting: Guildance To 2021 Part L Regulations
Type and thickness of TETRiS required
The Code for Sustainable Homes
Incorporating Cellecta high performance thermal & acoustic insulation products into elements of a dwelling will help reduce the building’s impact on the environment and will enable builders and developers to gain Code for Sustainable Homes credits (CSH).
Credits can be gained from four of the nine assessment categories detailed in The Code:
Category 1 – Energy [Ene 1]
15 Code credits are available for improving the DER over the TER. eg. ground floor U-values improved from 0.25W/m2 K to 0.16W/m2 K.
Category 3 – Materials [Mat 1]
Adopting a construction listed on the BRE website: www.thegreenguide.org.uk, which incorporates one of Cellecta’s insulation products can result in up to 15 Code credits being awarded.
Category 6 – Pollution [Pol 1]
1 Code credit is awarded when all the insulation materials in the elements listed below only use substances that have a global warming potential (GWP) of < 5, eg. TETRiS ecoblocks:
- Roofs: including loft hatch
- Walls: internal and external, including lintels and all insulation products
- Floors: including ground and upper floors
- Hot water cylinders, pipe insulation and other thermal stores
- Cold water storage tanks
Category 7 – Health and Well-being [Hea 2]
Incorporating one of Cellecta’s high performance acoustic treatments will also result in points being awarded. Contact our helpful technical team for further information.
The TETRiS system has been awarded a BRE Green Guide rating and gains 3 Code credits (element number 820140051).
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