Got a question? The InstaGroup experts have put together some Double Glazing FAQs, along with some advice on our other products and services.


Our Double Glazing FAQs cover the most common queries, from our initial survey through to installation.

Book a new obligation survey and we can answer the questions that are unique to your home.


The lifespan of a window or door depends on the quality of the product and workmanship.

Signs they may need replacing can include misted window units (due to failure of double glazing seals), warped or rotting timber frames and perished, peeling or discoloured plastic surrounds. If you have sash windows, you might notice they won’t open or close properly. You may also notice doors or windows rattling, or letting in draughts and cold, or the hinges, handles or locks may be broken.

Upgrading to a new energy efficient front door or new double glazed windows can improve your home’s insulation and comfort, as well as enhancing its security and appearance.

Single glazed windows could be letting out up to a third of a home's heating. Depending on the size and type of property, installing energy efficient double glazing could save you around £80 every year on heating bills. Plus, new windows will keep you warmer and more draught-free at home.

The £80 savings quoted are based on installing A-rated double glazing in a previously single glazed semi-detached house with gas heating. Energy prices as of February 2018.


Check accreditations and the ability for the company to self-certificate their work. The best window companies can be identified by their affiliation to trade bodies such as GGF, BFRC, FENSA, CERTASS and BBA.
Look for a long trading history, it's a good indicator that you can trust any work they carry out.

You should also check out the company’s online reviews and satisfaction ratings, including customer testimonials and installation pictures.

Once we've carried out a home survey and ordered the windows and/or door you have chosen, we'll give you a date for the installation. This is usually around 4-8 weeks after ordering, depending on the manufacturer, any planning permission required, and the installer availability for your location.

We'll keep you in touch at every step of the process.

The time it takes to install double glazing can vary on how many windows we're fitting, and any other home improvements you’re making at the same time. As a guide, a single window can take around 3 hours to install, a full house around a day.

A single front door can take just 3 hours to install.
We'll provide you with an accurate timescale when booking your installation date.

Up to a third of burglaries in a home occur through a window. This could involve smashing the glass (if single glazed), removing external frame beads to lift out the glass, or levering open the sash.

With good quality double glazing a window is more secure -- its frames, hardware and glazing all work together to prevent easy entry.

Good windows have multi-point locking, a key lockable handle and strong frames and hinges. You can check for reassuring security credentials by looking for windows that have been certified to PAS 24:2012.

Many burglars target a home by its front door, with a significant number of break-ins occurring after forcing cylinder locks in weak uPVC handles.
Upgrading to a secure new door can really improve your home's security, with the frame, hardware and glazing all working together to prevent entry. Look for a door with multi-point locking, a key lockable handle and strong frames and hinges. If glass is a feature on your new door, ensure its toughened glass.

You can check for reassuring security credentials by looking for doors that have been certified to PAS 24:2012.