There are no set U-Values for compliance with Approved Document L1A for new-building residential buildings. The performance requirements for individual elements will be set by the designer, and will vary as required in order to give the desired SAP 2009 emission result.
As with new-build housing requirements, AD L2A for new buildings other than dwellings is based on carbon performance of the whole building. A calculation process has to be followed and the Simplified Building Energy Model (SBEM), developed by the Building Research Establishment (BRE), is the methodology for carrying out these calculations. Although there are area-weighted limiting U-Values, the performance requirements for individual elements will be set by the designer, and will vary as required in order to give the desired SBEM emission result.
Although an energy calculation process can be followed as per new buildings, the Regulations lay down some very specific U-Values for the building fabric and this is the most likely route that developers will follow. The U-Values will vary depending upon several factors, such as the work being carried out and the thermal performance of the existing element at the outset. Please refer to our web site section covering Building Regulations for a clear guide to the U-Value requirements.
Guidance is given in BS5422: 2009 Table 29. However, no matter what thickness of insulation, if the pipes are at sufficiently low temperatures for a long enough period, freezing will occur. Table 29 details a 12 hour period with a water temperature of 2 ºC and an ambient of minus 10 ºC. We recommend trace heating in this case.
Yes we can. We offer this calculation service. Please contact your local representative with specific design details such as ambient, operating temperatures, dimensions of pipe/ duct or tank as well as information to an internal external location.
Isover glass mineral wool is very easy to fit. It’s flexible and friction fitted and holds in place between timber/metal frames/rafters without the need for additional fixings. This is unlike rigid boards which are solid, need to be cut to size and do not hold in place between timber/metal frames/rafters. All Isover packaging now includes a set of text and icons to represent important handling and health and safety information. These icons follow latest EURIMA (European Mineral Wool Manufacturers Association) guidelines and have been developed to ensure that health and safety information is shown in a consistent, common format to all insulation users.