G3 Doors & Windows - Perla Windows

G3 Steel Doors & Windows

The gold standard in slimline steel performance

G3 represents the highest standard in the G-Series range — combining elegant sightlines with advanced thermal insulation and increased structural capacity. Achieving a U-value of 1.0 W/m²K and vent heights up to 3.0 m, G3 enables ambitious glazed openings with precision and stability. Flush or overlapping design options, advanced glazing compatibility and a range of finishes allow it to integrate seamlessly into contemporary façades and large-scale elevations. Where scale, efficiency and refinement must coexist, G3 delivers performance without compromise.

G3 features

1.00 W/m2K uValue
Highly energy efficient slimline steel profiles
Up to 3.0m vent height
Large vent sizes allow for total design freedom
RAL finishes
Powder-coated finishes in any RAL colour
Sound insulation
Cancels out exterior noise up to 45db (-2.5)
Thermal barrier
Heat-resistant glass fibre reinforced insulating bars
Burglary resistance
Tested in accordance with EN 1627 up to RC2
2000Pa wind load
Certified C5 Class to meet EN 12210
600Pa air permeability
Certified 4 Class to meet EN 12207
600pa water tightness
Certified 9A Class to meet EN 12208

System overview

Design & Construction

High-performance profiles

Cold formed and sharp-edged 1.5 mm thick galvanized steel profiles – high precision production lines
Continuously laser welded profile, high mechanical performance
Can be both internally and externally flush or overlapping, or externally flush and internally overlapping
Profile depth compatible with insulating glass up to 56 mm
Fiberglass-reinforced polyamide insulator
Wide range of glazing beads, rectangular, triangular and double “L” shape
Epdm co-extruded sealing gaskets
Wide choice of specific fittings, including both visible and conceived hinges
Side-hung, single and double leaf inward or outward-opening windows and doors. Bottom-hung windows inward- opening. Top-hung and projected top- hung windows, outward-opening. Fixed glazing. Folding doors.

Minimal sightlines

With a construction depth of 75 mm, the face width of the leaf and frame is just 64 mm, adding up to a slim 75 mm in the face plate.

75 mm
profile depth
64 mm
leaf & frame
75 mm
face plate

Maximum dimensions

Element sizes of up to 1200 mm width x 3000 mm height per leaf (max. 190 kg leaf weight)

120 cm
leaf width
300 cm
leaf height
190 kg
leaf weight

Design options

Finishes

Powder coated

Coated steel strikes the perfect balance between function and style. From classic RAL colours to bold textures, coated steel blends strength with outstanding visual and mechanical performance.

Classic steel

Hot-rolled steel profiles feature a consistent texture, making them ideal for various finishes. Brushing or blackening offers an alternative to traditional painting, offering a high degree of customisation.

Cor-Ten steel

Cor-Ten is a natural, living material, celebrated for its remarkable visual impact and refined elegance, making it highly sought after for windows and doors in renovation and restoration projects.

Stainless steel

With its exceptional technical properties, stainless steel is a material of great popularity. Known for its metallic sheen, stainless steel allows for a wide range of design options.

Mullions

TDL mullions

TDL mullions break up the depth of the frame and separate glazing sections. The interface between TDL mullions and the frame is seamless, with joints that are flawlessly welded, polished, and finished.

SDL mullions

SDL mullions feature a glazing bar that is adhered directly to the surface of the glass. The glazing unit is full-sized, completely filling the frame, with the glazing bars applied in any configuration.

Glazing beads

G3 1520E — Steel, Cor-Ten steel, stainless steel

G3 1515A — Steel

G3 1515E — Steel

G3 1515R — Aluminium

G3 1520R — Aluminium

G3 1520S — Aluminium

Hinges

3D Screw-on hinge

G3 projects

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Lukasz Jagiello
Office Assistant

lukasz@perlawindows.com
+44 0 203 950 1451

Lukasz supports the wider team across planning, scheduling, and coordination—keeping operations running behind the scenes. His flexibility allows him to step in wherever needed, helping to maintain momentum across projects.

Drawing on experience in warehousing, hospitality, and admin support, Lukasz understands how to manage competing demands while keeping client needs front and centre. His organised, proactive approach ensures nothing is overlooked.

Kate Baranowska
Accounts & Office Manager

kate@perlawindows.com

Kate looks after the company finances and ensures that office and business operations run smoothly. Her responsibilities are wide-ranging and include human resources, compliance and insurance, solving any problems that arise, and ensuring that all Perla projects are progressed efficiently.

A natural multitasker, Kate has the ability to switch from role to role without breaking a sweat. She takes care of all the moving parts to keep the office running like clockwork.

Sebastian Baranowski
Technical Director

seb@perlawindows.com
+44 0 203 906 1777

Perla co-founder and Technical Director, Sebastian, oversees the planning and specification phases of the production process. He also acts as the main point of contact for clients prior to manufacturing and installation.

Sebastian’s extensive knowledge of design and production stems from a life-long interest in manufacturing and engineering. Starting out as a plumber and electrician alongside his father in the family business, Sebastian went on to establish a partnership with Nick and Dan’s building company. Together, they completed more than 100 projects and built a reputation for uncompromising quality.

Karol Ziolkowski
Project Manager

karol@perlawindows.com
+44 0203 906 1775

Karol oversees day-to-day project delivery, ensuring each stage runs smoothly and efficiently. He works closely with both internal teams and clients to keep timelines on track and expectations aligned.

With a BA in Business Management and a background in logistics and operations, Karol brings sharp attention to detail and strong technical knowledge to every project. His process-driven approach helps prevent issues before they arise, creating a more streamlined experience for clients.

Nick Vassilopoulos
Sales / Marketing and Business Development

nick@perlawindows.com
+44 0 203 906 1776

Nick co-founded Perla to provide unparalleled standards for service, value, and quality in the windows industry. Drawing on his past experience in marketing, at technology giant Intel, Nick’s primary focus is on the bigger picture. With astute awareness of market trends and an inherent understanding of customer needs, Nick implements positive change so that Perla can continue to be at the forefront of an ever-evolving market.

Prior to establishing Perla in 2015, good friends Nick and Dan ran a London-based boutique building company focused on high-end renovations and interiors projects.

Dan Hellin
Sales Director

dan@perlawindows.com
+44 0 203 906 1776

Prior to co-founding Perla, Dan spent 10 years as a Partner at the prestigious renovations company he established with Nick in 2005. With a sharp eye for detail and a meticulous approach to planning, Dan’s account management approach draws on more than 25 years’ experience in the building industry.

Having overseen a huge variety of residential and commercial projects, Dan knows how to resolve issues long before they become problems. His broad experience in building processes ensures every project runs on-time, on-budget and according to the business’ ethos of providing incredible service and impeccable quality.