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mySecondary Glazing Cost
At a Glance
- The average cost of secondary glazing installation is around £3,000.
- The job will usually take between 1 and 2 days to complete.
- A closer look at secondary glazing costs and what impacts these.
- How much the alternatives to secondary glazing cost, to help you make an informed decision.
- How to find and hire a local window fitter with MyJobQuote.
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Table of Contents
Secondary Glazing Cost Calculator
How Much Does Secondary Glazing Cost?
For the average UK homeowner, secondary glazing costs around £3,000 to install in 2026.
However, secondary glazing prices vary depending on the number of windows you want to apply secondary glazing to and your location in the UK. The average cost of secondary glazing is usually between £180 and £400 per window.
To get the best efficiency from secondary glazing, should it be installed as near to the existing windows as possible?
"Yes, this is correct. It ensures greater thermal efficiency."
Secondary glazing involves installing an extra set of glazing on the inside of an existing window. It can be a permanent addition, or can be installed just as a temporary measure.
Secondary glazing is often installed for the same reasons as double glazing, to offer better insulation and soundproofing. However, secondary glazing costs significantly less than double glazing.
It can also be your best option if you're living in a listed property and aren't permitted to replace your windows.
For listed buildings or conservation areas, the slim aluminium frames used for secondary glazing are unobtrusive and almost invisible from the outside, retaining the external character of your property. Planning permission is not usually needed for internal secondary glazing, and listed building consent is often not required if the glazing can be removed without damaging any historic features.
Secondary Glazing Prices
| Job Description | Total Estimated Costs |
|---|---|
| Partial Replacement (4 windows) | £1,350–£1,950 |
| Small terraced house (around 8 windows) | £2,750–£3,350 |
| Semi-detached house (around 10 windows) | £3,700–£4,200 |
| Detached house (around 15 windows) | £5,500–£6,150 |
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Secondary Glazing Windows Costs by Type
Let's take a look at the cost of different types of secondary glazing:
| Type of Secondary Glazing | Estimated Cost Per Window |
|---|---|
| Lift-Out Secondary Glazing | £180–£250 |
| Horizontal Slider Unit | £200–£300 |
| Vertical Slider Unit | £220–£325 |
| Hinged Glazing Unit | £275–£400 |
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How Much Is Secondary Glazing Installation & How Long Does It Take?
On average, professional window contractors will charge around £130 to £200 per day for labour. A secondary glazing installation often requires two contractors, so you can expect the labour costs to be around £260 to £400 per day of work.
The timeframe to install secondary glazing will vary depending on the size of your home and the number of windows that you want the secondary glazing to be fitted to.
Here's what you need to know:
| Job Description | Duration | Labour-only Cost |
|---|---|---|
| Partial Replacement (4 windows) | Up to 1 day | £260–£400 |
| Small terraced house (around 8 windows) | 1 to 2 days | £260–£800 |
| Semi-detached house (around 10 windows) | 1.5 to 2.5 days | £390–£1,000 |
| Detached house (around 15 windows) | 3 to 4 days | £780–£1,600 |
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Factors That Impact Secondary Glazing Costs
The cost of secondary glazing can vary depending on the type of system you choose, the size and style of your windows, and the condition of the existing frames. Below is a breakdown of the main factors that will affect the total price of your project.
Type of Secondary Glazing
The style you choose has one of the biggest influences on cost. Simple fixed panels tend to be the most affordable, while sliding, hinged or lift-out units usually cost more due to the additional hardware and labour involved.
Window Size and Shape
Larger windows require more materials and take longer to fit, increasing the overall price. Unusual shapes, bays, and period-style windows may also need custom-made panels, which raises both manufacturing and labour costs.
Frame Material and Finish
The frame used to hold the secondary glazing can impact the price. Aluminium and timber frames cost more than basic uPVC or lightweight options but typically offer better durability and aesthetics. Coloured, powder-coated or wood-effect finishes may also add to the cost.
Accessibility and Installation Complexity
Windows that are easy to access are quicker to work on and therefore cheaper. Upper-storey installations, tight internal spaces, deep reveals or awkward frame layouts take longer and may require additional fixings or equipment, increasing the installation cost.
Location in the UK
Your location in the UK can also affect the cost that you are going to pay. Labour costs in London are around £30 to £60 more per day, so the labour costs can add up for those living in and around London.
Existing Window Issues
If your current windows or frames are not in good condition, the installer may need to carry out extra work before fitting the secondary glazing. This can include:
- Repairing Damaged Frames — rot, warping or loose components must be fixed so the new glazing sits securely and seals correctly.
- Smoothing or Levelling Uneven Surfaces — rough or uneven reveals may require sanding or preparation to ensure a proper fit.
- Removing Old Secondary Glazing or Fittings — dismantling outdated panels, film kits or previous DIY installations can add time and cost.
These issues are common in older properties, and although they increase the total cost, they ensure the new glazing performs properly and lasts longer.
Optional Extras
Additional features such as toughened glass, acoustic-rated units, safety locks, ventilation panels, or bespoke trims can increase the price further. These upgrades are worth considering if you live on a busy road, in a noisy area, or want improved energy efficiency.
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Secondary Glazing Alternatives
There are some alternatives to secondary glazing available.
Below is a list of the alternatives to secondary glazing that you may wish to consider:
Double Glazing Costs
Double glazing windows contain sealed units that are created using two pieces of glass. The gap between the two panes of glass provides good insulation for the home against the cold weather outside.
Typically, double glazing costs between £120 and £350 per window.
Pros
- ✔ Good insulation, helping to prevent condensation.
- ✔ Can lower energy bills, and increase property value.
- ✔ Better durability and security.
Cons
- ✖ More expensive than secondary glazing.
- ✖ Failed sealed units usually need replacing.
Triple Glazing Costs
Triple glazing windows contain sealed units that are created using three pieces of glass. The gap between the three panes of glass provides good insulation for the home against the cold weather outside.
On average, triple glazing costs around £330 to £550 per window.
Pros
- ✔ Excellent insulation, reducing the chance of condensation.
- ✔ Can lower energy bills, and increase property value.
- ✔ Better durability, security, and soundproofing.
Cons
- ✖ More expensive than secondary glazing and double glazing.
- ✖ Can't be repaired.
- ✖ Bulky, and the extra weight can put a strain on hinges and joints.
FAQs
Does Secondary Glazing Stop Condensation?
Not on its own. Moist air getting into the gap can cause condensation on the original window, so the inner glazing should seal well while allowing the gap to ventilate through the outer window. Any existing damp problems should also be dealt with before installation.
Will Secondary Glazing Make My Rooms Too Hot in Summer?
Secondary glazing can make a room feel warmer in summer if it limits how much you can open the windows for ventilation. Blinds or curtains can help reduce heat from the sun, while opening the glazing for ventilation or removing suitable panels during warmer months can help keep rooms comfortable.
Is Secondary Glazing Suitable for Rented Properties?
Secondary glazing can work well in rented homes because it is installed on the inside and, in removable form, can avoid permanent changes to the existing window frames, but tenants should always get their landlord's written permission first. Many landlords choose permanent secondary glazing as a long-term energy and comfort upgrade, while renters often favour magnetic or clip-in kits that can be removed or even taken with them when they move out.
Can I Open My Windows Normally Once Secondary Glazing Is Fitted?
Yes, most modern secondary glazing systems are designed so you can still ventilate your home, using horizontal or vertical sliders, hinged units or opening panels that broadly mirror how the original window operates. With fixed or magnetic panels you may need to lift out or unclip the panel before fully opening the primary window, so how easy it is to use day to day will depend on the style you choose.
Can I Install Secondary Glazing Myself?
For many straightforward windows, secondary glazing can indeed be a viable DIY project if you are confident and opt for simple magnetic or clip-in panels.
However, accuracy and attention to detail are vital. Measurement errors or misaligned panels can lead to gaps, which may compromise heat retention, soundproofing, and draught control, or even risk damaging the existing window frame. DIY kits can be cost-effective, but they often compromise performance when compared with professionally installed systems.
