Replacement Double Glazed Glass Only Prices in the UK: 2026

Replacing just the double glazed glass costs £55 to £180 per sealed unit fitted in the UK. That range runs from the Faron low end of £55 to the JobPrices high end of £180, and the typical standard unit costs about £140. A large bay or conservatory unit costs £237 to £345 fitted. Replacing the unit can cost up to 50% less than a new window, which is why it is worth pricing before you order a full window.

The sealed unit is the glass itself: two panes held apart by a spacer bar and sealed at the edges, with gas in the gap. When the seal fails, damp air gets in and the unit mists up between the panes. The glass is the only part that has failed, so the frame, the hinges and the handles can stay. A glazier measures the unit, orders a new one and swaps it in the same frame.

Figure 1: Water droplets covering a window pane. Misting between the panes, not on the surface, is the sign of a failed seal, and it means the glass unit needs replacing.

Glass only prices by size

JobPrices puts the minimum charge for a visit at about £180, so a single small unit can cost more than the unit price alone. Faron puts all the units in a 3-bedroom semi at £1,400 to £2,500, which is a useful check on a whole-house quote.

Glass only vs a new window

A full uPVC casement window costs £350 to £650 fitted, against £55 to £180 for the glass alone. JJS Glass puts the saving at up to 50% less than a new window. The saving is real when the frame is sound: you keep the frame, the hinges and the handles, and you pay for glass and labour only. A new window is the right call when the frame is rotten, warped or damaged, or when the hinges and seals have gone too.

Worked example: 8 misted units in a semi

Take a semi-detached house with 8 misted units. At the JobPrices typical figure of £140 per unit, the glass-only bill is 8 times £140, which is £1,120. Eight new uPVC casement windows at £350 to £650 each cost £2,800 to £5,200. The glass-only route saves about 60% against the low end of the new-window price, and more against the high end. That is the comparison to make before you sign for new windows: count the misted units, multiply by £140, and set that against the window quote.

When glass only works

• The frame is sound: no rot, no warping, no cracked corners. The new unit needs a straight frame to seal against.
• The misting is between the panes: wipe the inside face. If the mist stays, the seal has failed and the unit needs replacing.
• The unit is a standard size: odd shapes and very large units cost more and take longer to order.
• The hinges and handles still work: if they have gone too, a new window may be the better buy.

Sources: JobPrices misted double glazing repair cost UK 2026, checked 11 November 2026 (standard sealed unit fitted £96 to £180 incl VAT, typical £140; large bay or conservatory unit £237 to £345; minimum charge a visit about £180); Faron Home Improvements, updated October 2026 (sealed unit £55 to £145; small £55 to £75; large £115 to £145; all units in a 3-bedroom semi £1,400 to £2,500; full uPVC casement window £350 to £650); Bracknell Window Repair, published 5 November 2026 (standard clear unit £80 to £150 fitted; 10-year manufacturer guarantee); JJS Glass, updated 1 November 2026 (sealed unit £90 to £250 fitted; replacing the unit can cost up to 50% less than a new window). Prices checked 14 November 2026.

Frequently asked questions