Energy Saving Calculator

Cost Saving Secondary Glazing Calculator

To work out the cost saving for the whole building, simply enter the details of the property.

Type of Primary Window
Taken from the Pilkington Spectrum Glass uValue calculator using 4mm Optifloat clear annealed for single glazed and Air filled 4mm Optifloat clear annealed for double glazing.

U Value W/(m²K) Primary & Secondary Window Combined
U-Value based on Granada’s slimline hinged unit, with 6mm low-e glazing and a 50mm cavity.

How many windows do you have?
Based on average window dimensions of 2000mm x 1000mm

Internal Temperature
Based on lower external average temperatures of 2°C Winter and 9°C Summer.

The below is based on 6 months in summer and 6 months in winter

Unit Cost Per kWh (£)
Current UK average as of Oct 23.

Whole Building

*This calculator is based on estimates according to verified thermal test data. Results may vary depending on individual circumstance. We advise that you confirm expected performance before placing an order. Thermal data can be provided upon request.

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