Window Energy Ratings and Energy Saving Products

Energy-rated windows can significantly reduce annual heating bills and help increase the value of a property.

Windows and doors are energy-rated under the same system that is given to household appliances such as washing machines and fridges, which are graded between A and G, depending on their environmental efficiency – ‘A’ being the most efficient.

Current Building Regulations for all types of window installation require a minimum ‘C’; rating, which can be increased to ‘A’ – the most energy-efficient product – where no heat loss occurs.

Document ‘L’ Compliance and WERs

Worsley Glass PVC-U windows, doors and conservatory products help installers, specifiers and homeowners maximise the benefits of window energy ratings and U-values.  All our products are manufactured to achieve full compliance with the latest legislation and building regulations.

What is a Window Energy Rating (WER)?

Window Energy Ratings provide a benchmark for comparing the energy efficiency of different window systems. The rating is a single number that measures a window’s overall energy performance. Building regulations currently stipulate a minimum requirement of ‘C’ (or a U-value of 1.6 W/m2K) for all window installations.

It is calculated by measuring the energy flow through a standard window (1.23m x 1.48m) and takes three variable factors into account:

  • The heat transmitted into the building through the glass from the sun (solar gain)
  • The heat loss from the building through thermal transmittance of the window components (expressed as the whole window U-value)
  • The heat loss resulting from air leakage through the weather seals

The energy efficiency of a window is shown by the widely-recognised Window Energy Rating.

Few things will make a greater difference to the warmth, security and look of your home than high-performance, energy-saving windows. For more details on energy efficiency and U-values and how to achieve the best possible energy rating contact us.