Velux Skylights vs Flat Skylights: Key Differences and Cleaning Considerations

Skylights are becoming increasingly common in London homes. Many homeowners add them during loft conversions, kitchen extensions, or renovations to bring in more natural light and make interiors feel more open.

Two of the most common types you’ll see are Velux skylights and flat skylights. While both serve the same purpose—letting natural light into your home—their design, installation, and maintenance needs can be quite different.

It is important to understand these differences if you want to maintain your skylights and keep the glass looking clear over time. In this article, we will explain how Velux skylights and flat skylights differ, as well as why they often require a slightly different approach when it comes to cleaning than regular windows.

Velux Skylights

Velux skylights are a familiar sight in many London homes, particularly in loft conversions. They are designed specifically for pitched roofs, which means the window sits at an angle rather than horizontally.

Because of their design, Velux skylights often include moving parts and frames that allow the window to open for ventilation.

Some common characteristics of Velux skylights include:

• Installed on sloped or pitched roofs

• Often openable for airflow and ventilation

• Built with frames, seals, and hinges

• Many models can rotate or tilt inward

This design makes Velux windows practical for rooms such as loft bedrooms or converted attic spaces.

While the sloped position helps rainwater wash away some dust and debris naturally, that doesn’t mean they stay clean on their own. Over time, pollution, pollen, and airborne particles still settle on the glass and frames.

In urban areas like London, this build-up can gradually dull the appearance of the glass if it isn’t cleaned regularly.

Flat Skylights

Flat skylights are commonly installed in modern home extensions, especially kitchen or living room extensions with flat roofs.

Unlike Velux windows, flat skylights typically consist of a large horizontal glass panel that sits on top of the roof structure. They are often fixed in place and do not open.

You’ll often recognise flat skylights by these features:

• Installed on flat or low-slope roofs

• Usually fixed (non-opening)

• Made with large glass panels

• Designed for maximum natural light

This design can create a striking architectural feature and allow a large amount of daylight to enter the room.

However, the horizontal position also means flat skylights are more exposed to the elements. Dirt, dust, leaves, and rainwater can sit on the glass surface for longer periods compared to vertical and slanted windows.

Because water does not always run off quickly, mineral deposits and environmental residue may dry directly on the glass, leaving visible marks over time.

Why Skylights Often Get Dirtier Than Regular Windows

If you’ve noticed that your skylights seem to look dirty faster than your standard windows, this is mainly due to their position and exposure.

Unlike vertical windows, skylights face upward and collect whatever falls from above or drifts through the air.

Some common causes of skylight build-up include:

• Rainwater that dries on the glass and leaves mineral residue

• Pollen and organic debris settling on the surface

• Airborne pollution from traffic and nearby construction

• Dust and particles carried by wind

Over time, these materials accumulate on the glass. When combined with sunlight and moisture, they can leave visible spotting or streaks that are difficult to remove with basic cleaning.

Flat skylights are particularly prone to this because their horizontal surface allows dirt to sit for longer periods.

Cleaning Velux and Flat Skylights Safely

Cleaning skylights can be more complicated than cleaning regular windows, especially when they are located on upper floors or roof areas that are difficult to reach safely.

Attempting to clean them from the roof without the right equipment can be risky, and using the wrong tools may scratch or damage the glass.

Professional window cleaners in London typically use specialised methods designed to clean elevated glass surfaces safely.

At The Riviera Group, we use purified water through our water-fed pole systems, which allows us to clean skylights from the ground while still achieving excellent results. The purified water removes dirt without leaving mineral residue behind, helping prevent streaks or spotting as the glass dries.

Velux Skylights or Flat Skylights: Which Should You Choose?

Both Velux skylights and flat skylights are excellent ways to bring more natural light into your home. While their designs are different, both types are exposed to the elements and can gradually collect dirt, pollution, and mineral deposits over time.

Regardless of which skylight you pick, you’ll need regular cleaning in order to keep the glass clear and for it to continue brightening your living space as it was intended to.

If you are looking for expert skylight cleaning services in London, you’ve come to the right place. Our team at The Riviera Group uses a reach and wash system to clean Velux skylights, flat skylights, and other hard-to-reach glass safely while protecting the surface from scratches or damage.

If your skylights are starting to look cloudy or marked, book a professional clean today and let the natural light shine through again.