Commercial Glass Extension
Commercial glass box extensions
Structural glazing with minimal sightlines, built to passive house standards and manufactured off site to keep your downtime short. Restaurant extensions, showrooms, atriums and office links, across the UK.
Designed & installed nationwide • 10-year warranty • Full Design & Build Service
Structural glass architecture
Glass architecture built for commercial use
A glass box extension adds permanent floor area with almost no visible structure. Large format panes, structural silicone joints and slim thermally broken frames, so what you see is glass and what you get is a room performing to modern thermal standards rather than a cold conservatory. On a commercial site the two things that decide the job are downtime and performance. We manufacture off site wherever the design allows, so the disruptive part on your premises is measured in days rather than months, and we specify glazing to passive house levels because a large glazed room on a restaurant or office that leaks heat becomes a running cost argument within a year. Design, planning, structural engineering, building control and installation all sit with us. We survey the existing structure first, because what the building will carry usually shapes the design more than anything else.
Why a glass extension
Why businesses build in structural glass
A glass extension is bought for two reasons: it adds usable, lettable, rateable floor area, and it makes a building look considerably more expensive than it did. Both show up commercially in a way an outdoor structure does not.
Adds usable floor area
A fully enclosed, heated and regulated space counts as building area, so it adds capacity, asset value and lettable square footage.
Off-site manufacture
The structure is made in the factory and assembled on site, which cuts the time your premises spend as a building site.
Passive standards
Triple glazing, thermal breaks and airtight detailing keep the running cost of a large glazed room defensible.
Minimal sightlines
Structural silicone joints and slim profiles mean uninterrupted glass, which is what separates this from a conservatory.
Engineered spans
Thermally broken structural steel and frameless glass beams open up spans that would otherwise need posts through the middle.
Planning managed
Planning applications, structural calculations and building control are handled by us as part of the design and build.
Specification
Building a commercial glass extension
Structure, glazing and thermal detailing are engineered around the existing building and the span, then manufactured to those figures rather than to a catalogue size.
- Structural silicone bonded joints
- Large format and oversized panes
- Off-site manufactured modules
- Sliding and pivot glass doors
- Triple glazing to passive standards
- Integrated blinds within the glazing
- Thermally broken structural steel
- Solar control and low-e coatings
- Underfloor heating ready
- Level access thresholds throughout
Structural glass extensions
Built up from the ground on site where the design needs to follow an awkward footprint, a change in level or an existing structure that cannot be worked around. Structural silicone joints carry the loads through the glass itself, so vertical framing largely disappears and the corners can be glass to glass. This is the specification for a flagship space: a restaurant frontage, a showroom, a boardroom on a courtyard. Structural engineering is done properly at design stage because the glass is doing structural work.
Off-site manufacture
Where the design allows, the extension is manufactured as modules in the factory and assembled on your premises in a short, planned window. For a trading business this is usually the deciding factor, because the alternative is months of a live building site next to your customers. Factory conditions also produce tighter tolerances and better airtightness than site assembly in British weather. It needs crane access and a clear programme, both of which we work out at survey rather than on the day.
Rooflights, atriums and links
Not every glass extension is an extension. Glazed links between two buildings, rooflights over a dark central floorplate, and full atriums all use the same structural glazing and the same thermal detailing. These are frequently the highest value jobs on an existing commercial building because they fix a daylight problem that no amount of internal work will solve. The junction between old and new is where the attention goes: drainage, movement and thermal bridging at that line decide whether it performs.
FAQ
faq h2
A few of the things business owners ask us most often. Anything else, just ask.
How much trading time will we lose?
Less than a traditional build, which is the point of manufacturing off site. Groundworks and the connection to the existing building are the disruptive stages; the glazed structure itself goes up quickly once it arrives. We agree a programme before starting so you can plan around it.
Does a commercial glass extension need planning permission?
Almost always. Commercial premises have far narrower permitted development rights than houses, and anything altering a frontage, a shopfront or a listed building needs consent. We handle the application, and we will give you an honest read on the likelihood before you spend money on a full design.
How do you deal with glare and solar gain?
Orientation first, then glass. Solar control coatings, body-tinted glass and integrated blinds within the cavity handle most of it, and on office and restaurant projects we model the aspect rather than guessing. A glass room that has to keep its blinds down was specified badly.
How wide can it span without posts?
Further than most people expect, using thermally broken structural steel or glass beams. The limit is set by loading and the existing building rather than the glass. We establish it at survey, because designing around a span you cannot achieve wastes everyone time.
What will it cost to heat?
Considerably less than an older glazed structure. Triple glazing, thermal breaks and airtight detailing to passive house levels are what make a large glazed commercial space viable to run. Specify it as a conservatory instead and the heating bill becomes the story within the first winter.
BEGIN Your project
contact h2
Tell us a little about your business and we will be in touch to arrange your design consultation, at the showroom or at your property.
Prefer to talk?
Call us on 0113 518 3766
or email us at info@glasshousearchitecture.co.uk