Colchester · Essex
Secondary Glazing in Colchester
Our surveyors can measure windows across Colchester for secondary glazing, checking reveal depth, opening style and fire escape needs before quoting.
- CO1
- CO2
- CO3
- CO4
- Guide from £465
About secondary glazing for sash windows in Colchester
If an existing window is relied on for escape in a fire, the secondary glazing in front of it must open easily and give enough clear opening. The surveyor checks which windows are escape windows, so the opening style and catches do not block a way out.
For noise reduction, the size of the air gap between the original window and the secondary unit matters a great deal, and a wider cavity generally performs better. Acoustic laminated glass and well-sealed frames improve results further, especially against traffic, rail and aircraft noise.
Slim aluminium frames are designed to sit within the window reveal and line up with the original glazing bars or meeting rails. Matching sightlines keeps the secondary unit discreet from outside and inside, which matters for period homes and conservation areas.
Secondary glazing leaves the original window untouched and fits a second, independent window inside it. The air gap between the two works with the glass to reduce noise and heat loss. In most cases the installation can be taken out later without damaging the historic window or reveal.
Included as standard
- Survey of each window, reveal depth and sightlines
- Fitting, sealing and checking every opening panel
- Removal of packaging and cleaning of new glass
- Made-to-measure slim aluminium frames and glass

Colchester at a glance
- Postcodes covered
- CO1, CO2, CO3, CO4 and the surrounding area, including Sudbury, Clacton-on-Sea and Witham
- Coast
- Colchester sits roughly 6 km from the nearest coastline, close enough that exposure on open or high ground is worth considering. Coastal properties often have older windows exposed to wind-driven rain and draughts. Secondary glazing adds a sealed inner layer that reduces draughts and cold, while the original window keeps out the weather and its condition is protected from inside.
- Daylight and sun
- In Colchester the midwinter sun reaches about 15° above the horizon at noon, with roughly 7.5 hours of daylight, rising to about 62° and 16.5 hours in midsummer. Secondary glazing adds an extra layer of glass, which slightly reduces daylight. Low-iron or clear low-E glass keeps light loss to a minimum, while on sunny elevations solar control glass can help reduce overheating in rooms with large windows.
- Access and setting
- In city centres and busy streets, acoustic secondary glazing is a common response to traffic, rail and nightlife noise. Flats, listed buildings and conservation areas often limit external changes, which makes internal secondary glazing a practical option.
- Rules in England
- Approved Document K requires safety glass in critical locations in England: glazing in doors and in side panels within 300 mm of a door, up to 1500 mm above floor level, and any glazing in walls or partitions up to 800 mm above floor level.
Guide prices in Colchester
| Typical job | Guide price inc VAT |
|---|---|
| Slider, 900 × 1200 mm | £465 – £595 |
| Slider, 1200 × 1600 mm | £665 – £845 |
| Acoustic glass, 1000 × 1400 mm | £675 – £865 |
Get a guide price for your size
Approved Document L sets the minimum energy performance for replacement windows and doors in existing homes in England: a U-value of 1.4 W/m²K, or Window Energy Rating band B for windows; doors can instead meet a Door Set Energy Rating (band B, or band C for doors more than 60% glazed); rooflights need 2.2 W/m²K.
Specification choices
Vertical sliding
Panels slide up and down, with meeting rails aligned to sash windows so the secondary unit is discreet from inside and outside.
Low-E glass
Coated glass that reflects heat back into the room, improving insulation when the original window is single glazed.
Horizontal sliding
Panels slide sideways, suiting wide casement windows and openings where you need regular access for cleaning or ventilation.
Secondary Glazing in Colchester: questions
Does secondary glazing need safety glass?
It does in critical locations. In England, glass within 800mm of the floor, glass in doors and glass near doors are critical locations under Approved Document K, and these apply to secondary glazing too. Low-level secondary panes should be toughened or laminated safety glass. The surveyor checks each window during the survey.
Is secondary glazing as good as double glazing?
It depends on the goal. For noise, secondary glazing is often more effective, because the wider gap between the two windows reduces sound better than the narrow cavity of a sealed unit. For heat, a well-sealed secondary unit with low-E glass significantly improves a single-glazed window. It also keeps original windows, which matters in listed buildings.
Is secondary glazing suitable for rented homes and flats?
Yes. Secondary glazing is fitted inside, so it often avoids the external changes that leases, freeholders or planning rules restrict. It can be removed later with limited making good. Leaseholders should still check their lease for any rules on internal alterations, and landlords should check escape routes are not affected.
Do I need permission for secondary glazing on a listed building?
You should seek listed building consent from the council's planning department before installing secondary glazing on a listed building. Secondary glazing is often seen as a reversible, low-impact change, but consent requirements depend on the building. Carrying out works that need consent without it is a criminal offence. If your home is not listed but is in a conservation area, check with the council if you are unsure.
Do you cover Colchester for secondary glazing?
Yes. We can quote for secondary glazing across Colchester and the surrounding Essex area, including postcode districts CO1, CO2, CO3 and CO4, and nearby Sudbury, Clacton-on-Sea and Witham. 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 Colchester
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