Lisburn · County Antrim
Misted Glass Repair in Lisburn
Cloudy, streaky double glazing in Lisburn is usually a failed sealed unit, and we can quote to replace it without disturbing the frame.
- BT27
- BT28
- BT17
- Guide from £155
Foggy window replacement in Lisburn: what to know
Early seal failure often shows only on cold mornings or after rain and clears during the day. As the desiccant fills, the mist lasts longer and white mineral staining can form on the inner faces. Staining inside the unit cannot be removed by cleaning from either side.
A misted unit is a good opportunity to upgrade an older plain glass unit to one with a low-emissivity coating and gas fill. The new unit reduces heat loss through the glass and keeps the room-side pane warmer, without any change to the frame.
A sealed unit has a spacer bar around its edge filled with desiccant, a drying agent that absorbs any moisture inside the cavity. When the edge seal fails, damp air keeps getting in until the desiccant is saturated, and condensation then forms between the panes where it cannot be wiped off.
The price of replacing misted units depends on the size of each unit, the glass specification, any bars or decorative features, how many units are done together, and access. Several units on one visit usually cost less each than separate visits for single windows.
What's included
- Written quote fixing the price for the specification
- Measurement of each failed sealed unit
- Fitting on packers with drainage slots checked
- Removal of old units and cleaning of rebates

Working in Lisburn
- Postcodes covered
- BT27, BT28, BT17 and the surrounding area, including Carryduff, Belfast and Castlereagh
- Coast
- Lisburn sits roughly 12 km from the nearest coastline, close enough that exposure on open or high ground is worth considering. Salt air and wind-driven rain put extra strain on sealed unit edges in coastal homes. Keeping frame drainage clear and gaskets in good order matters more, and the glazier checks both so the replacement unit is not sitting in trapped water.
- Daylight and sun
- In Lisburn the midwinter sun reaches about 12° above the horizon at noon, with roughly 7.0 hours of daylight, rising to about 59° and 17.0 hours in midsummer. Units on sunny south and west elevations go through bigger daily temperature swings, which stresses the edge seal over time. In colder, darker months, mist between the panes is often most visible, so the survey is a good time to confirm failure.
- Access and setting
- In flats and terraced streets, replacing misted units often means planning access, parking and carrying units up stairs. Upper-floor windows may need to be done from inside, and conservation areas may require matching bars or glass patterns.
- Rules in Northern Ireland
- Technical Booklet V covers safety glazing in Northern Ireland, including glass in and around doors and low-level glazing where people could walk into it.
Guide prices in Lisburn
| Typical job | Guide price inc VAT |
|---|---|
| One misted unit, 600 × 900 mm | £155 – £195 |
| Two misted units, 600 × 900 mm | £305 – £395 |
| Four misted units, 600 × 1100 mm | £685 – £875 |
| Misted unit in a door, toughened | £305 – £385 |
Get a guide price for your size
Technical Booklet F1 sets the energy performance that replacement windows, doors and rooflights need to meet in Northern Ireland.
Specification choices
Georgian bar or leaded
Decorative bars or lead designs remade to match the originals so the new unit lines up with neighbouring windows.
Low-E upgrade unit
A coated pane and gas-filled cavity that reduce heat loss compared with older plain glass units, fitted in the same frame.
Toughened safety unit
Both panes toughened, for misted units in doors, beside doors or low down where safety glass is required.
Misted Glass Repair in Lisburn: questions
How long does it take to replace a misted unit?
There are usually two visits. The first is a survey to measure each unit. The second is fitting, once the new units have been made to order. Fitting usually takes a short time per window, with little mess. Your quote sets out when the units are expected, and we will tell you honestly when a glazier can attend.
Will a new unit match my other windows?
It can. The glazier records the unit thickness, spacer bar colour, any Georgian bars or leaded designs, and the obscure glass pattern if there is one. Most details can be matched closely. If an obscure pattern has been discontinued, the quote offers the closest available alternative so you can decide before anything is ordered.
Can you clean the inside of a misted double glazing unit?
Not without breaking the seal. Some firms drill the glass, flush the cavity and fit a small vent, which can clear the mist for a while. It does not restore an airtight seal or gas fill, and white staining may not fully clear. Replacing the unit is the reliable way to restore a clear, sealed cavity.
Is it worth replacing misted units or should I get new windows?
If the frames are sound, square and the hinges and locks work, replacing only the misted units is usually the more economical option. New windows make more sense if the frames are rotten, warped, draughty or hard to open. The glazier checks the frames at the survey and the quote will say if replacing units is not good value.
Do you cover Lisburn for misted glass repair?
Yes. We can quote for misted glass repair across Lisburn and the surrounding County Antrim area, including postcode districts BT27, BT28 and BT17, and nearby Carryduff, Belfast and Castlereagh. Start with your postcode on the quote form and a glazier will arrange a free survey before giving you a written quote.
Get a written quote in Lisburn
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.