The short answer
DIY secondary glazing is the lowest-priced route. Supply-only acrylic or glass kits typically start from around £160 per window, with a standard sash often near £295 supplied, against roughly £250–£700 per window fitted by an installer. At the budget end, magnetic acrylic panels and removable insulating film can cost as little as £10–£40 per window for a temporary winter fix. DIY works well for standard, square, single-pane windows and for draught and warmth gains. It is harder to get right for serious noise reduction (which needs a deep, well-sealed air gap) and for awkward or out-of-square period windows, where a measured, professionally fitted system usually performs better.
If budget is the priority, DIY secondary glazing can save a lot — but the saving depends on the system and on your windows being straightforward. Here is what the options cost and where they earn their keep.
Typical DIY costs
- Supply-only kitfrom ~£160 / window
- Standard sash, supplied~£295
- Magnetic acrylic panel~£20–£60 / window
- Insulating film (temporary)~£10–£40 / window
- Fitted by installer£250–£700 / window
The DIY options and what they cost
- Supply-only kits: aluminium-framed acrylic or glass panes you measure and fit yourself, from roughly £160 per window — the closest DIY gets to a permanent install.
- Magnetic panels: a lightweight acrylic sheet held on a magnetic strip, around £20–£60 per window, easy to remove for cleaning or summer.
- Insulating film: shrink-fit plastic film, around £10–£40 per window, a cheap seasonal fix for draughts rather than a lasting upgrade.
- Versus fitted: a professional supplied-and-fitted window runs £250–£700, so DIY can roughly halve the cost on a straightforward window.
| Option | Typical cost | Best for |
|---|---|---|
| Supply-only kit | from ~£160 / window | permanent DIY on standard windows |
| Magnetic acrylic panel | ~£20–£60 / window | removable, light draught & warmth |
| Insulating film | ~£10–£40 / window | temporary winter draught fix |
| Professionally fitted | £250–£700 / window | noise, period or awkward windows |
Indicative UK figures for guidance. Sources: trade and supplier cost guides.
Where DIY works and where to pay for fitting
DIY makes most sense on standard, square, single-glazed windows where the goal is warmth and fewer draughts — there a supply-only kit or magnetic panel gives a real improvement for a fraction of the fitted price. It is harder to get a good result where you need serious noise reduction, because that depends on a deep, accurately set air gap and tight seals, or where windows are out of square, very large, or part of a listed or period home that needs a sympathetic, made-to-measure system. In those cases a measured survey and professional fit usually justify the extra cost.
Not sure whether to DIY or have it fitted?
We'll match you with a vetted secondary-glazing installer who can survey the windows and quote a fitted option, so you can weigh it honestly against the DIY route.
Frequently asked questions
How much does DIY secondary glazing cost?
Supply-only kits typically start from around £160 per window, with a standard sash often near £295 supplied. Budget options like magnetic acrylic panels (£20–£60) and insulating film (£10–£40) cost less but offer less, against £250–£700 per window professionally fitted.
Is DIY secondary glazing any good?
For standard, square windows where the aim is warmth and fewer draughts, DIY kits and magnetic panels give a real improvement for much less. They are harder to get right for serious noise reduction or for awkward and period windows, where a fitted system usually performs better.
Can I fit secondary glazing myself in a listed building?
Take care — on a listed building even a DIY install can require listed building consent because it is still an alteration. Check with your conservation officer before fixing anything to a historic window.
Sources & further reading
Figures on this page are typical UK ranges drawn from published sources and depend on your specific windows. They are guidance, not a quotation.