Windows – making it clear: energy, daylight and thermal comfort

Many considerations have to be taken into account in the selection of windows.

However, achieving a good trade-off between energy performance and daylighting, while minimising the risk of overheating, is a particular challenge for today’s designers. In this guide, using the results of new modelling carried out for the NHBC Foundation, the impact of window choice on performance is shown for a range of typical home types.

It illustrates how glazing type, frame width, overall window area and orientation affect performance and includes design aids to steer towards the best options, and away from those with less satisfactory outcomes for occupants.

The guidance is developed from modelling results using the Passivhaus Planning Package (PHPP); specialist software designed to provide sophisticated analysis of energy use and comfort within homes.