Fixed Glazing
Large thermally insulated glazed elements with visible steel widths from only 23 mm.
Forster Steel Profile Systems
Ultra-Slim Thermally Insulated Steel System
forster unico XS
An exceptionally slim thermally insulated steel system for windows, doors and fixed glazing, combining maximum transparency with high thermal performance and the structural elegance of steel.
Steel · Thermal Performance · Transparency · Precision
01 / System
Thermally Insulated Steel Architecture
The elegance of historic steel.
The elegance of historic steel.
Engineered for modern performance.
forster unico XS is an ultra-slim thermally insulated steel profile system developed for windows, doors and fixed glazing in sophisticated exterior architecture.
Its unique all-steel construction enables profile dimensions that would normally be difficult to achieve with conventional thermally insulated systems, allowing exceptionally narrow visible sections while maintaining high levels of thermal and acoustic performance.
The system is particularly suitable for contemporary architecture as well as the renovation of historic, industrial and listed buildings where original steel-window proportions need to be respected.
23 mm
Fixed Glazing Face Width
Extremely slender visible profiles for high-transparency steel glazing.
65 mm
Door Leaf + Frame
The latest unico XS door construction achieves exceptionally slim proportions.
70 mm
Construction Depth
Thermally insulated all-steel profile architecture.
300 kg
Maximum Door Leaf Weight
Large-format entrance doors are possible with suitable profile and hardware selection.
02 / XS Design
Ultra-Slim Steel Profiles
Less visible frame.
Less visible frame.
More architecture.
unico XS combines modern thermal insulation with proportions traditionally associated with historic steel windows and finely detailed architectural glazing.
23 mm
Minimal Fixed Glazing Face Width
Slim steel sections preserve maximum glass area, natural light and the distinctive visual character of architectural steel glazing.
01
All-Steel Construction
The profile structure is engineered in steel without conventional plastic thermal isolators, helping maintain extremely slender proportions.
02
Historic Proportions
Ideal for replacing traditional steel windows while preserving delicate architectural lines and façade rhythm.
03
Large Glass Areas
High steel rigidity enables large glazed elements while keeping profile dimensions visually restrained.
04
Concealed Hardware
Selected window configurations can use concealed fittings for an even cleaner architectural appearance.
03 / Typologies
Windows · Doors · Fixed Glazing
One slim architectural language.
One slim architectural language.
Multiple exterior configurations.
Side-Hung Window
Slim inward- or outward-opening steel windows for contemporary and historic projects.
Tilt & Turn
High-performance window configurations combining practical ventilation with minimalist steel proportions.
Exterior Door
Ultra-slim thermally insulated steel doors for refined residential and commercial entrances.
04 / Performance
Slim Without Compromise
Architectural delicacy.
Architectural delicacy.
Modern building-envelope performance.
Thermal Insulation
0.80
W/m²K · Fixed Glazing*
High-performance glazing and the thermally optimised steel profile construction support demanding contemporary envelope requirements.
Door
Ud up to 0.85
Representative thermal performance for suitable side-hung door configurations.
Fixed Glazing
Uw up to 0.80
Excellent thermal insulation for large glazed steel elements.
Acoustic Comfort
Up to Rw 47 dB
High acoustic insulation is available in appropriate window and glazing configurations.
Security
RC2
Burglar-resistant window and fixed-glazing configurations are available.
05 / Technical
Technical Characteristics
Engineered around
Engineered around
a 70 mm steel platform.
forster unico XS
Thermally Insulated Steel System
Profile & Glazing
Profile Material
Steel
Construction Depth
70 mm
Wall Thickness
1.5 mm
Fixed Face Width
From 23 mm
Door Leaf + Frame
From 65 mm
Glazing Thickness
Up to approx. 60 mm*
Dimensions & Performance
Single Door
Up to 1400 × 3000 mm*
Double Door
Up to 2800 × 3000 mm*
Fixed Glazing
Up to 3000 mm high*
Maximum Door Leaf
300 kg*
Burglar Resistance
RC2*
CE / UKCA
EN 14351-1
*Technical values depend on element type, dimensions, glazing, hardware, profile selection and certified configuration. Window, door and fixed-glazing performance values should always be verified according to the final project specification and applicable Forster technical documentation.
06 / Dimensions
Large Steel Elements
Slender proportions.
Slender proportions.
Impressive dimensions.
Single Leaf Door
1400 × 3000
mm
Maximum clear opening for suitable single-leaf door configurations, depending on profile selection.
Double Leaf Door
2800 × 3000
mm
Large double-leaf exterior entrances can retain the distinctive slim unico XS aesthetic.
Fixed Glazing
∞ × 3000
mm
Fixed glazing may extend horizontally through modular construction while reaching heights up to 3000 mm.
07 / Comfort
Performance Beyond Appearance
Slim steel profiles
Slim steel profiles
with serious technical capability.
01
Thermal Insulation
High-performance thermally insulated
steel profile architecture.
02
Acoustic Insulation
Sound reduction up to approximately
Rw 47 dB in suitable configurations.
03
RC2 Security
Burglar-resistant windows and glazing
available in certified configurations.
04
Concealed Fittings
Selected configurations support concealed
hardware for cleaner sightlines.
08 / Renovation
Historic Steel Architecture
Preserve the proportions.
Preserve the proportions.
Upgrade the performance.
XS
Heritage-Compatible Steel Design
unico XS is particularly suited to projects where traditional narrow steel-window aesthetics must be maintained while thermal performance is significantly improved.
01
Historic Buildings
Fine steel proportions make the system suitable for sensitive architectural renovation.
02
Industrial Heritage
Ideal for warehouses, factories and loft conversions where original steel character forms part of the architecture.
03
Modern Performance
Thermal and acoustic performance can be dramatically improved while preserving narrow visual profiles.
04
Contemporary Architecture
The same proportions work equally well in modern minimalist residential and commercial projects.
Responsible Steel
Designed for
Designed for
a long life.
unico XS combines architectural durability with a recyclable steel profile concept and modern environmental documentation.
- 100% recyclable steel profiles
- No conventional plastic profile insulator
- Long service-life potential
- High structural durability
- Low Carbon Emission Steel available
- Environmental Product Declaration available
- Suitable for adaptive reuse projects
- Ideal for renovation instead of replacement architecture
Key Features
unico XS
unico XS
at a glance.
A thermally insulated steel platform combining ultra-slim proportions with exterior-grade performance.
- Fixed glazing face width from 23 mm
- Door leaf + frame from 65 mm
- 70 mm construction depth
- Thermally insulated steel construction
- Windows, doors & fixed glazing
- Glazing thickness up to approx. 60 mm
- Single doors up to 1400 × 3000 mm
- Double doors up to 2800 × 3000 mm
- Door leaf weight up to 300 kg
- Acoustic performance up to Rw 47 dB
- RC2 configurations available
- Ideal for historic & contemporary architecture
Steel Window & Door Project Enquiries
Bring ultra-slim steel performance to your project.
Contact Mparolas for forster unico XS windows, entrance doors, fixed glazing, architectural detailing and project-specific thermally insulated steel solutions.
