Frameless Structural Glass Extensions
No Frames • No Compromise • Pure Architecture
A frameless glass extension removes the barrier between inside and out. Our structural glass systems use advanced sealant bonding instead of visible frames, creating rooms made entirely of glass—with exceptional thermal performance and year-round comfort.
Why a Frameless Glass Extension Changes Everything
A framed extension—however slim the profiles—always announces itself. A frameless structural glass extension does the opposite: it disappears, leaving only light, view, and the original architecture of your home. Our structural sealant bonding eliminates visible mullions and transoms entirely, creating glass-to-glass joints that are engineered to commercial standards but designed for residential beauty.
Every extension is engineered with advanced solar control glazing—high-performance coatings, argon-filled cavities, and warm-edge spacer bars. The result is a thermally efficient room that stays comfortable year-round, not a greenhouse that overheats in June and freezes in January. Frameless glass is also preferred by many Planning and Conservation Officers for listed buildings, because it allows the original fabric to remain visible.
Glass Box Extension vs. Frameless Roof Light: Which Suits Your Project?
Both use the same structural glass technology. The choice depends on your property, how much space you need, and the architectural effect you want.
Glass Box Extension
Full Room • Maximum Impact
A glass box extension adds an entirely new room to your home—walls, roof, and often floor in frameless glass. The structural sealant bonding creates invisible joints, so the extension appears to float against the original building. Ideal for kitchen-diners, garden rooms, and living spaces where you want a seamless connection between inside and outside.
Frameless Roof Light
Light From Above • Minimal Footprint
A frameless roof light floods an existing room with natural light without altering the footprint of your home. Flush-mounted into the roofline, it creates a striking architectural feature while dramatically improving the quality of light in kitchens, hallways, and living areas below. Walk-on options allow rooftop terrace access.
Frameless Glass vs. Aluminium vs. UPVC Extensions
The extension method you choose affects views, thermal performance, maintenance, and how well the addition integrates with your existing property.
Frameless Structural Glass
Aluminium Extension
UPVC Extension
Engineered to Disappear, Built to Last
Frameless structural glass extensions are engineered for homes where views, comfort, and architectural integrity cannot be compromised.
Structural Sealant Bonding
Commercial-grade sealants create invisible glass-to-glass joints with exceptional load-bearing capacity. No frames, no mullions—just pure glass architecture.
Thermal Excellence
Warm-edge double glazing, low-E coatings, and argon gas fill exceed Part L Building Regulations. Your glass extension stays comfortable in every season.
Heritage Expertise
Trusted for listed properties and conservation areas across the South East. Frameless glass keeps original building fabric visible—conservation officers prefer it.
Solar Control Technology
Advanced coatings prevent overheating in summer and retain heat in winter. Choose clear, tinted, or reflective glass to suit your orientation and preferences.
What Goes Into a Frameless Glass Extension
From structural engineering to the final sealant joint – every glass extension is built to perform and built to last.
Premium Glass Specification
Toughened, laminated, or tempered glass selected for each application. Every pane is precision-cut and finished to exact tolerances for flawless frameless joints.
Structural Sealant Bonding
Commercial-grade structural sealants replace visible frames entirely. Glass-to-glass joints provide exceptional load-bearing capacity and a pure, seamless aesthetic.
Solar Control Glazing
High-performance coatings reduce solar gain in summer and retain warmth in winter. Choose from clear, tinted, or reflective options depending on orientation.
Walk-On Glass Capability
Class A BS6206 rated glass strong enough to be safely walked on—enabling rooftop terrace access above your extension or flush-level maintenance access.
Bespoke Structural Design
No standard templates. Each glass extension is custom-engineered with structural calculations, glass thickness specifications, and thermal modelling for your exact project.
10-Year Structural Guarantee
Backed by UK insurers. Covers structural integrity, glass units, and workmanship—full terms supplied with your quotation.
Frameless Glass Extension Configurations
Every configuration is fully bespoke. These are the most common starting points for frameless structural glass projects.
Glass Box Extension
Frameless Roof Light
Glass Link Extension
How Homeowners Use Frameless Glass Extensions
Every project starts with how you want to live. Here is how homeowners have used frameless structural glass to transform their homes.
Listed Building Kitchen Extension
A frameless glass box extension added to a Victorian townhouse. The structural glass allows the original brickwork to remain fully visible, satisfying conservation requirements while creating a stunning, light-filled kitchen dining space with uninterrupted garden views.
Garden Studio Glass Connection
A frameless glass link connects the main house to a new garden studio, creating a seamless visual corridor between living and working spaces. A walk-on roof light above the link doubles as a terrace for the first floor, adding outdoor space without sacrificing light below.
Considering a frameless glass extension for your home?
Book a free home design visit. We will assess your property, discuss planning and structural considerations, and recommend the best frameless glass solution—with no obligation.
Call us anytime on 01243 538999 – David our digital assistant will take a few details so the right specialist can follow up personally.
How Your Frameless Glass Extension Project Works
From first conversation to finished installation—engineered for precision at every stage.
Free Home Design Visit
A specialist visits your home to discuss your vision, assess the site, and take measurements. We advise on planning requirements, structural considerations, and glass specification options.
Structural Design & Engineering
We produce detailed engineering drawings specifying glass thickness, sealant bonding, thermal performance, and structural load calculations. You see exactly what the finished extension will look like before any work begins.
Manufacture & Installation
Glass units are precision-cut and toughened off-site. On-site installation uses structural sealants and specialist fixings—we manage the full build from foundations to completion.
Handover & Aftercare
We do not consider a project complete until you are fully satisfied. Your frameless glass extension is covered by a 10-year structural guarantee backed by trusted UK insurers.
What Our Customers Say
Real homeowners sharing their experience of working with Room Outside – unedited and in their own words.
“Room Outside did an amazing job with our glass extension. The design is modern, the build quality is excellent, and the team was professional from start to finish. The space is bright, comfortable all year round, and has completely transformed our home. Highly recommended for anyone looking for a premium glass extension.”
“What a fabulous service. I am so pleased with the work that Matt and Room Outside have carried out. I was recommended to use them and I am so pleased that I did. They are certainly a Company you can trust. Very happy with the end result and I will certainly be recommending them to all.”
“We are absolutely delighted with our experience with Room Outside and cannot recommend them highly enough. From the very beginning, Richard guided us through the design process with patience, professionalism, and integrity. The end result is beyond what we imagined – a beautiful, high-quality glass extension that has transformed our home.”
Frameless Glass Extension FAQs
Common questions about frameless structural glass extensions—design, planning, thermal performance, and what to expect.
A frameless structural glass extension uses advanced sealant bonding instead of visible aluminium or timber frames. Glass panels are joined directly to each other using commercial-grade structural sealants, creating a room that appears to be made entirely of glass. The result is unobstructed views, maximum natural light, and an architectural elegance that framed alternatives cannot match.
Many glass extensions fall under permitted development rights, but this depends on your property’s size, location, and listed status. If your home is in a conservation area or is listed, planning permission is usually required—but frameless glass is often preferred by conservation officers because it allows the original building fabric to remain visible. We handle all planning checks and applications as part of our service.
Not with the right glass specification. Our extensions use advanced solar control coatings that reflect excess solar heat in summer while retaining warmth in winter. Combined with warm-edge spacer bars and argon gas fill, the result is a room that stays comfortable year-round. We specify the glass based on your extension’s orientation and exposure to ensure optimal thermal comfort.
Our glass meets Class A of BS6206—dense toughened glass strong enough to be safely walked on. Structural sealant bonding provides exceptional load-bearing capacity comparable to commercial glazing systems. The glass is engineered to withstand wind loading, snow loading, and impact forces with a significant safety margin.
Yes. Walk-on glass roofs are one of our most popular configurations. The glass is specified to Class A BS6206 standard—safe for pedestrian traffic. This allows you to create a rooftop terrace above your extension, or simply enables safe access for cleaning and maintenance. Anti-slip coatings are available for added safety.
A typical frameless glass extension takes 8–14 weeks from design approval to completion, depending on size, complexity, and planning requirements. The glass units are precision-manufactured off-site while groundwork and foundations are prepared, which keeps the overall programme efficient. We provide a detailed timeline with your quotation.
Start your frameless glass extension project today
Glass box extensions, frameless roof lights, and glass links—designed to disappear, engineered to last.
Call us anytime on 01243 538999 – David our digital assistant will take a few details so the right specialist can follow up personally.