Structural Corner Windows — London & the Home Counties
Two fixed panes meeting at 90° with no visible mullion — a modernist detail popular in rear extensions and kitchen returns where the corner of the room becomes the view. Structurally engineered in thermally-broken aluminium.
The moment post inside
The corner is engineered like a small piece of structure. A hidden steel or aluminium moment post inside the frame carries the load from above without a visible column — leaving just a silicone-bonded glass corner outside.
Overview
A closer look at what makes the structural corner windows range distinctive — the specification, the styles, the process, and the answers to the questions we get asked most.
Thermally-broken aluminium frame · concealed steel or aluminium moment post · structural silicone corner bond · argon-filled toughened double glazing
No Visible Corner Mullion
Two fixed panes are silicone-bonded at 90° with a structural corner post inside the frame — from outside, the glass simply turns the corner.
Structural-Glass Engineering
Engineered as a load-carrying assembly with a hidden steel or aluminium moment post — supports the head detail above without a visible column.
Kitchen Return Favourite
The signature detail of a modern rear extension — a corner window at the sink or breakfast bar turns the whole side elevation into glass.
Fixed or Openable
Standard configuration is two fixed panes. Openable side lights can be added away from the corner where ventilation is needed.
Any RAL Powder Coat
Matched to the surrounding aluminium windows, sliders and doors — single or dual colour, Qualicoat Class 2.
Coordinated Delivery
Site-surveyed, factory-glazed and lifted into position as a single assembly — no on-site glazing at the corner joint.
Three material ranges, one configuration.
The structural corner configuration is available across every one of our window ranges — the material choice is yours.
Engineered to the millimetre.
Every frame we install is made to your survey sizes with the following performance envelope as standard.
- U-value (whole window)
- 0.9 – 1.4 W/m²K
- Configurations
- Fixed + fixed · fixed + opener · opener + opener (rare)
- Max height
- 2.6 m per pane · surveyed and engineered per project
- Corner joint
- Structural silicone bond over concealed moment post
- Finish
- Any RAL Qualicoat Class 2 · matched across full elevation
- Lead time
- 6–8 weeks · site-surveyed and engineered before manufacture
Structural Corner Windows across London
and the Home Counties.
We install structural corner windows across six counties — every project surveyed, made and fitted by our in-house team. Choose your county to read local knowledge, planning notes and recent work.
See all areas coveredStructural Corner Windows — installed.
A selection of recent installations across London and the Home Counties, photographed on site.
Practical answers.
Everything homeowners ask us about structural corner windows — survey, lead times, guarantees and coverage.
Do I need an engineer for a corner window?+
Yes — the corner needs a structural design because it carries load from above without a visible column. We coordinate with your project engineer and provide the CAD detail, or we can supply structural calculations ourselves via our engineering partner.
Can the corner be an opening window?+
The corner itself is always fixed — the structural silicone bond can't take a hinged sash. Openable side lights can be positioned away from the corner if ventilation is needed.
How is it installed?+
The two panes are glazed into the frame in the factory and delivered as a single assembly. On site, we lift it into position (usually with a Hiab crane) and seal it to the surrounding brickwork or cladding.
What affects a structural corner window design?+
Pane dimensions, glass specification, site access, the hidden moment post and any supporting steelwork above all shape the design. Every corner is surveyed and engineered individually.
Enquire about
Structural Corner Windows.
Speak with our design team, book a home survey, and receive a fixed written quotation — all with no obligation.
Call · 020 3633 0405