All toolsCalculatorsSustainabilityDegree Day Energy Estimation
Degree Day Energy Estimation
Estimate annual space-heating energy, cost and carbon from a building heat-loss coefficient and UK regional heating degree days.
The Ensign ToolboxDegree Day Energy EstimationEstimate annual space-heating energy, cost and carbon from a building heat-loss coefficient and UK regional heating degree days.
Heat-loss coefficient
W/K
Whole-building fabric + ventilation loss coefficient
Degree days
20-year average, base 15.5 °C (CIBSE TM41 / Degree Days Direct)
K·day
Override with a local or base-temperature-corrected figure
Heating system
%
ErP A-rated condensing boiler ≈ 90%
Unit price & emission factor
£/kWh
kgCO₂e/kWh
Enter the heat-loss and system figures to estimate annual energy