Everest Home Improvements is actively marketing secondary glazing as an alternative to full window replacement in the UK. The company positions the retrofit solution for homeowners seeking lower-cost upgrades and for listed buildings where planning restrictions prevent replacement. Secondary glazing involves fitting a second pane internally behind existing windows – typically costing 40–60% less than new windows while delivering similar thermal improvements. Rising energy bills and growing heritage property renovation activity are boosting demand for the historically niche product category, Everest says.