Cambridgeshire is full of beautiful old buildings: Georgian townhouses in Cambridge, Victorian terraces in Ely, cottages around Huntingdon and period homes near Newmarket. Many still have single-glazed sash or casement windows that are beautiful and keep the character of the building, but are cold to live with. Replacing them with double glazing is often not allowed due to being listed or in a conservation area and rarely desirable. Secondary glazing units are the intelligent answer.
What is secondary glazing?
It is a slim, independent glazed panel fitted on the inside of your existing window. The air gap between the two creates insulation and a sound barrier, while the original window stays exactly as it is. From the outside the look and character of the property doesn’t change.
Why Secondary glazing units suit listed and conservation properties
- Reversible: it can be removed without trace, leaving original frames untouched.
- Discreet: slimline frames can be colour-matched and aligned with glazing bars and meeting rails.
- Effective: it dramatically reduces heat loss and draughts through single glazing, and can cut external noise significantly.
- Protective: it adds a barrier that helps protect fragile historic glass.
Do I need listed building consent?
Secondary glazing units are often acceptable where replacement windows are not, because it is reversible. However, requirements vary, so always speak to your local authority’s conservation officer before work starts. We are happy to provide product details and drawings to support that conversation.
Choosing the right style of Secondary glazing units
- Vertical sliding: mirrors sash windows, so the meeting rails line up.
- Horizontal sliding: good for wide casements.
- Hinged: opens like a door, easy for cleaning and ventilation.
- Lift-out: for windows you rarely open.
- Fixed: the simplest option for non-opening windows.
We measure each opening during our initial survey, so the panels sit neatly within the reveal. We also offer a supply-only options.
Secondary glazing units vs Fineo
If the existing sashes are sound and you would like the glass itself upgraded, Fineo vacuum glazing may be an alternative. Check out our next article compares the two.
FAQs
Will it stop my windows opening? No. You choose an opening style so both windows can still be opened.
Does it cause condensation? A well-fitted system with the right ventilation keeps condensation under control. We will advise on your specific windows.
Which areas do you cover? Cambridge, Ely, Huntingdon, Newmarket and surrounding Cambridgeshire and Suffolk.
We are a trusted, local glass and glazing company- but don’t just take our word for it; visit our Trust Index page to see for yourself. Thinking about warmer windows before winter? Visit our Cottenham showroom or ask us for a free quotation Contact us today!
