Folkestone · Kent
Secondary Glazing in Folkestone
Single-glazed sash windows in Folkestone can stay as they are, with vertical sliding secondary glazing fitted inside to reduce draughts and cold.
- CT19
- CT20
- Guide from £465
Acoustic secondary glazing for homes and businesses in Folkestone
Low-level secondary glazing is still glazing, so the safety glazing rules for critical locations apply. In England, Approved Document K treats glass within 800mm of the floor as a critical location, so low-level secondary panes should be toughened or laminated safety glass.
Glass for secondary glazing is heavy, so the frames need firm fixings into the reveal or a supporting sub-frame. The surveyor checks that plaster, timber linings and window boards are sound enough to carry the weight, and allows for any packing needed in uneven reveals.
Opening styles include vertical sliders that line up with sash window meeting rails, horizontal sliders for wide openings, hinged casements, lift-out panels for windows that are rarely opened, and fixed panes. The choice depends on how you use the window, cleaning access and fire escape needs.
A low-emissivity coating on the secondary glass reflects heat back into the room and improves the insulation of the combined window. It is a useful choice for single-glazed sash and casement windows where the originals must be kept for character or planning reasons.
What a typical job includes
- Removal of packaging and cleaning of new glass
- Fitting, sealing and checking every opening panel
- Survey of each window, reveal depth and sightlines
- Advice on opening style, glass and fire escape

Folkestone at a glance
- Postcodes covered
- CT19, CT20 and the surrounding area, including Dover, Ashford (Kent) and Deal
- Coast
- Folkestone is about 1 km from the coast or a tidal estuary, so salt air and wind-driven rain are worth planning for. 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 Folkestone the midwinter sun reaches about 16° above the horizon at noon, with roughly 7.7 hours of daylight, rising to about 62° and 16.3 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 Folkestone
| 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.
Options to choose between
Hinged casement
Panels open inwards like a door, giving full access to the original window, and can be chosen for escape windows.
Horizontal sliding
Panels slide sideways, suiting wide casement windows and openings where you need regular access for cleaning or ventilation.
Low-E glass
Coated glass that reflects heat back into the room, improving insulation when the original window is single glazed.
Secondary Glazing in Folkestone: questions
How much does secondary glazing cost?
The cost depends on the size and number of windows, the opening style, the type of glass, any arched or shaped heads, reveal depth and access. Acoustic and low-E glass cost more than standard clear glass, and shaped frames need more work. See the guide prices for typical windows, then get a written quote after the survey.
How much noise does secondary glazing block?
Results depend on the size of the gap between the windows, the glass type and thickness, the seals and the original window. A larger cavity and acoustic laminated glass give the strongest improvement. The survey checks reveal depth and noise sources, so the specification can be tailored to the noise you are dealing with.
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.
Can I still open my original windows?
Yes, as long as the secondary glazing has an opening panel in front of the part you need to open. Sliding and hinged panels give access to the original window for ventilation and cleaning. Lift-out and fixed panels suit windows you rarely or never open.
Do you cover Folkestone for secondary glazing?
Yes. We can quote for secondary glazing across Folkestone and the surrounding Kent area, including postcode districts CT19 and CT20, and nearby Dover, Ashford (Kent) and Deal. 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 Folkestone
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.