Window film can be one of the most effective ways to improve comfort in a glass‑heavy home, but only when the right product is matched to the right glazing. The film itself is only half the story. The real value lies in understanding how modern glass behaves and choosing a film that will actually deliver meaningful heat reduction.
At WindowTreat, the advice you receive is as important as the film we install.
Why Advice Matters as Much as the Film Itself
Modern double glazing already reflects and absorbs a significant amount of solar energy. This dramatically changes how window films perform compared to older glazing systems.
Here is the key point most homeowners never hear:
On modern double glazing, internal films lose a huge amount of their heat‑rejection performance.
Why?
When you apply an internal film, much of the absorbed energy is reradiated back into the room.
The low‑emissivity coatings in the glass block a large part of the solar spectrum, limiting the film’s ability to work as effectively.
This is why the difference in price between 3M Prestige 70 Interior and 3M Prestige 70 Exterior is not dramatic, but the difference in performance is enormous.
Prestige 70 Interior on modern double glazing will have very little real‑world impact on heat.
Prestige 70 Exterior can dramatically reduce infrared heat while keeping the glass bright, clear, and visually unchanged.
Without the right advice, it is easy to choose a film that looks impressive on a datasheet but delivers almost no benefit once installed.
Our team ensures you avoid that mistake.
What Does Window Film Cost?
For a typical 6 metre wide, 6‑door bi‑fold, pricing varies depending on the technology and performance level.
Entry‑Level Films
From £1,000 fully installed including VAT
Advanced Spectrally Selective Films
Up to three times as much These include high‑technology films such as 3M Prestige Exterior Series, engineered to reject infrared heat while maintaining high levels of natural light and preserving the aesthetics of the glass. They are ideal for modern glazing where internal films can struggle to perform.
The true value is not just the film itself. It is selecting the right product and installing it with care so it performs for the next 15 to 20 years.
Why Installation Quality Matters
Most installers rely on the Glass and Glazing Federation (GGF) guidelines for visual quality. These guidelines allow a surprising amount of contamination behind the film to be considered acceptable. Dust, fibres, and small particles can all be present and still pass.
We take a very different approach.
Our Standard Is Higher
Our installers spend time thoroughly cleaning the glazing, gaskets, and framework before installation. This dramatically reduces the chance of contamination and ensures a cleaner, clearer finish.
Preparation Is The Key To Visual Quality
The time invested in preparation directly affects:
Visual clarity
Longevity
Adhesion
Edge stability
Overall appearance
We take the time because you will be living with the film for up to 20 years. A rushed installation may look acceptable on day one but will not stand the test of time.
The WindowTreat Difference
Window film is not a commodity. It is a performance product that must be matched to:
The glazing type
The orientation
The heat load
The aesthetic goals
The long‑term comfort requirements
We ensure:
You understand how films behave on your specific glass
You choose a product that delivers real, measurable results
The installation is carried out to a standard far above industry minimums
The film enhances and protects your home
When done properly, window film is one of the most effective ways to improve comfort and reduce solar heat gain.
