The short answer Secondary glazing cost: typically £300 to £500 per window installed in the UK, according to Checkatrade’s 2026 price guide. For a typical three-bedroom semi-detached house, a whole-project quote averages around £2,314. That is substantially less than full double glazing replacement, which runs £500 to £1,250 per uPVC window and £8,000 to £15,000 […]