Benefits of Frameless Windows - A guide for 2025

Frameless windows are a popular choice in modern property renovations and building projects.  Often specified for luxury homes, hotels and high-end renovations, there are few reasons not to use one in your home.

For most projects the instant visual benefit of frameless windows are increased natural light levels because of the lack of visible frame.  Whether viewed from inside or outisde, they provide a transformational look.

There are several considerations with frameless windows and as a specialist manufacturer of these, we at Glideline will explain  why they’re growing in popularity, the technical and aesthetic benefits they offer, how they are made, their overall performance and and what you should expect in terms of cost and installation. Whether you’re an architect, homeowner, or developer, here is all our expertise in one helpful guide to frameless windows in the UK in 2025.

What Are Frameless Windows?

Frameless windows use advanced glass-to-glass junction technology to create the illusion of a fully glazed window with no visible frame.

Unlike traditional windows, which have aluminium, timber, or PVCu framing around every edge, frameless units minimise or eliminate visible profiles on one or more sides.

There are several types of frameless windows, because each is bespoke made:

• Fixed structural glazing with glass bonded into a hidden frame or pocketed in the surrounding wall.

• Corner-to-corner glass joints, often seen in open-plan or wraparound designs.

• Corner joints with a very slim aluminium trim inside and outside to seal the corner.

• Butt-joint glazing, with structural silicone, where two panes meet without a mullion.

• A framed window with all the aluminium hidden in the structure to create a frameless window appearance, or one with the least amount visible.

At Glideline, our frameless windows are often built openings of varying sizes using our GW70 fixed window, which offers sleek lines and excellent performance with no visible sash.

Other types of frameless windows utilise glass technology only.  Often with frameless windows there is no set brand or system used.  How these windows are made always despends on sizes, corners needed and general design.

7 Key Benefits of Frameless Windows

1. Unobstructed 180° Views

Frameless windows maximise sightlines and create a glass vision panel.  Without any  frames or mullions, you gain a panoramic perspective. This is threefore ideal for homes with great views, open plan layouts or corners of rooms where you need to bring in more light.

More than 90% glass. Compared to typical window with around 60% made up of aluminium frame, a frameless window provides the maximum amount of glass.

Here is an example case study of how a framless window transformed a dark corner in a London Home.

2.  40% More Natural Light

Depending on how a frameless window is configured, and compared two the same design using standard frame and mullion/transom profiles, up to 40% more natural light is possible.

Lux readings are often used by professional to show the difference in light levels with different kinds of lighting including window design. Increased natural light contributes to wellbeing, reduces artificial lighting use, and improves indoor ambiance.

Energy savings are also measurable. Over a year, relying less on artificial lighting in high-usage rooms can reduce electricity bills depending on room size and use.

3. Modern Architectural Appeal

Frameless glazing suits contemporary and minimalist architecture perfectly.

• Flush finishes and clean lines complement modern cladding, render, or internal plaster.

• It removes visual clutter, allowing materials like timber floors, polished concrete, or exposed brick to take centre stage.

• Trend Watch: Architectural design in 2025 continues to favour uninterrupted glazing with invisible transitions between glass and structure—frameless windows are increasingly standard in luxury builds.

Frameless installations are also used to increase perceived property value, as buyers associate clean, minimal design with quality and architectural ambition.

4. Thermal Efficiency

Contrary to popular belief, frameless windows are not less efficient than framed windows. In fact, with the right specification, they can outperform them. 

With glass being the primary component in any window or door, and even with sliding door framels hidden in the structure, U-Values can be better than a standard product fitted directly into the aperture.

U-Values vary depending on the glass specification chosen.  There is no reason why U Values of 1.4Wm2K or less cannot be achieved. Frameless glass is also compatible with solar control coatings and low-e treatments.

In a typical UK property, upgrading to high-spec frameless units also helps reduce reduce annual heating costs, especially in south-facing elevations.

5. Low Maintenance & Long-Term Durability

Correctly made, propertly installed and with no exposed sashes or moving parts, frameless windows require very little upkeep.

• No repainting or re-coating like timber or steel.

• Cleaning time is reduced—no intricate frames to gather dust or trap dirt.

• Fully sealed units withstand even coastal or high-wind conditions.

Modern frameless systems, like our GW70, use marine-grade aluminium frames where visible, paired with high-perforamance safety glasss units.  Typically we use standard or solar control toughened or laminated safety glass, having a soft-coat low-emissivity coating, warm edge spacer bars and argon or krypton gas fill. 

There is no reason a frameless window cannot last for 30 years, compared to 15–20 years for a  standard PVCu window and with none of the plastic frame bulk.

All Glideline products include a 10-year guarantee on materials and manufacturing.

6. Space-Saving Design

Without projecting sashes or frame overhangs, frameless windows offer a cleaner internal finish and save valuable space—especially in smaller rooms or awkward corners.

• No swing clearance needed

• Maximises usable wall and furniture space

• Ideal for cloakrooms, utility rooms, lofts, and bathrooms

Flush installations also work well behind staircases or built-in joinery, providing natural light where a framed window wouldn’t fit neatly.  

 7. Acoustic Performance

Properly specified frameless glazing can reduce sound transmission significantly when specified with Acoustic Glass.  Many of the frameless windows we make for our clients use frameless corner or fixed glazing in city apartments and noise-sensitive environments to improve peace and comfort without compromising on design.

Frameless Windows Cost Guide UK

What Do Frameless Windows Cost in 2025?

The cost of frameless windows depends on size, specification, access, and installation method.

Installation is best provided separately given the assembly of these windows at the property and depending on the complexity.  You can expect at least 30% on top of the supply only prices for installation and there will be other associated costs.

Get a quote now for a frameless window

Considerations Before Installing Frameless Windows 

Installing frameless glazing requires careful design and planning. Consider the following before committing:

• Planning Permission: Whilst mostly falling within permitted development, it is worth checking with your local authority.

• Structural Requirements: Larger panels need structural support. Always involve an engineer if spanning wide or corner units.

• Privacy: Opt acid-etched, frosted or obscure glazing in sensitive areas.

• Cleaning: Accessibility for cleaning exterior surfaces—especially in upper-storey locations.

• Installation Expertise: Not every installer has experience with structural glazing. Always use a professional manufacturer and Glideline-trained partners.

• We do not recommend buying frameless windows for DIY or for your builder to fit. 

Frameless Windows vs Traditional Windows

When to Choose Frameless: For fixed glazing, corner designs, architectural impact.
When to Choose Traditional: Where regular opening and access are needed.

Glideline Frameless Window Systems

At Glideline, our bespoke frameless windows are the ideal solution for creating more light in an existing room or adding a visual statement in a new extension or new build home.

Precision made in our advanced factory, we use only high-specfication thermally insulated frames when used and the highest quality safety glass. Flush glass-to-glass joints are created with exterior-grade structural silicone and/or powder coated trims and sealant.

We can help you design the ideal frameless window with full specifications, drawings and installation support provided via our approved partner network. 

Frameless Windows FAQs

Are frameless windows more expensive?
Yes, they typically cost more than standard casement windows, because of their hand-built and bespoke nature.  Installation requires more expertise too.  However you do benefit from greater visual impact and longer-term value.

Are frameless windows always fixed picture windows?

Yes, because as soon as you incorporate an opener they need visible frame. We can help you design a frameless window with opening facility such as a cut-down sliding door fitted into the structure. Contact us for more information and advice.

Do they require special cleaning?
No specialist chemicals, but access for external cleaning should be planned—especially for larger or higher panels. Excessive contact with structural sealant should be avoided.

How long do they last?
There is no reason why you cannot enjoy a frameless window for 20-30 years or more with proper specification and installation as well as routine cleaning.

Are they energy efficient?
Yes. With the right glazing and insulation, frameless windows can achieve excellent U-values

Do I need planning permission?
Only in certain protected areas or when changing existing openings—check with your local planning authority.

Handcrafted Frameless Windows by Glideline – Get a free quotation today 

Frameless windows offer significant design and performance benefits.  From unobstructed views and light-filled spaces to high thermal performance and long-term durability.   Above all they are striking to look at and create light in your home.  Whether fixed or projecting, standalone or as part of a window seat, They can transform both the appearance and comfort of your home or building project.

Get expert guidance from Glideline – UK manufacturers of premium sliding doors and structural glazing.