The system allows for the construction of: 

• single and double casement windows,
• tilt windows,
• windows opening inwards and outwards
• pivot windows with a vertical and horizontal pivot axis for residences and post-institutional, revitalised, sacred and historical buildings.

Janisol 2.0 windows are ideally suited to the needs of builders and designers due to their very slender appearance and performance characteristics.
Minimum bend radius of up to 300 mm. 

A wide range of glazing baads, methods of use (opening), types of hinges, closures and handles allows the requirements of even the most demanding customers to be satisfied.

• Thermal insulation (1,3 ≤ Uf ≤ 2,0)
• Wind-load resistance up to class C5.
• Watertightness up to class 9A.

Copyright KönigStahl, System Jansen 

Originally developed for refurbishing historic steel windows, Janisol Arte takes slimness to the next level. This system features extremely narrow face widths (as low as ~25–40 mm for fixed glazing) that beautifully replicate classic industrial and Art Deco steel windows. Yet, Janisol Arte is fully thermally broken and supports modern insulating glass. The Janisol Arte 2.0 generation offers improved insulation and even includes options in Corten and stainless steel for unique aestheticsjansen.com. Janisol Arte profiles allow for bespoke mullion designs and nearly limitless configurations, so architects can match almost any historic sightline or create new patterns. Despite the ultra-slim look, these windows meet contemporary standards – offering reliable insulation, multipoint locking, and the ability to incorporate tilt-and-turn or fixed panels. Concealed fittings maintain the authentic look with uninterrupted sightlines. Many of these qualities make Janisol Arte the perfect choice for both landmark renovations and high-end modern residences seeking a timeless industrial style.

With Janisol Arte 66, Jansen is expanding its range of systems to include an attractive variation. The basic depth of 66 mm enables the use of stronger glass, with a vent height of up to 2300 mm. 

This makes it possible to have the turn/tilt opening type, even with the special requirements of listed buildings for narrow frames. With the concealed fittings, they meet architects' and developers' demands for a uniform design and clear lines which do not allow any visual interruption. 

The Euro grooves make it easier for fabricators to install the fittings, while the new glazing bead system facilitates installation of the panes. Fabrication with push-in gasket or dry glazing takes place in the usual way, as with the Janisol and Janisol Arte 2.0 steel profiles – this ensures a high level of process reliability.

• High thermal insulation (1,0 ≤ Uf ≤ 1,3)
• Wind-load resistance up to class C5.
• Watertightness up to class 9A.

Modern Thermal Performance: The standard Janisol window system offers a balanced solution for most projects. With a frame depth of ~60 mm, Janisol steel windows can accommodate double or triple glazing for excellent thermal performance. They maintain slender sightlines while providing the strength for large operable sashes (supporting vent weights up to 180 kg) and even structural glazing configurations. Janisol is suitable for new builds and retrofits alike, offering various opening styles (inward or outward) and even specialty options like horizontal pivoting windows. These profiles are available in galvanized steel or stainless steel (316L) for corrosive environments. Janisol windows are tested and certified for all key performance criteria, including air/water tightness and thermal transmittance, and can be configured as burglar-proof or bullet-resistant if needed.

The slender appearance of Janisol window profiles creates space for creativity and gives a building a unique character. Regardless of the variants of rungs, curved windows or large-format glazing: the Janisol window system has its strengths both in new construction and in the renovation of existing buildings.

• Thermally insulated (1,3 ≤ Uf ≤ 2,0)
• Leaf weight up to 180 kg
• Side-hung, tilt & turn, bottom-hung, top-hung and double-vent windows
• Burglary protection rating up to RC (WK) 3 in accordance with EN 1627

• Air permeability up to class 4

  Copyright KönigStahl, System Jansen 

Not every application requires a thermal break – for interior partitions, vestibules, or certain historic restorations, Jansen’s Economy series provides the classic steel look with simpler construction. 

Jansen Economy 50 is a steel/stainless steel profile system with an installation depth of only 50 mm, making it ideal for slender, elegant window designs without thermal insulation. 

Economy 50 windows match the appearance of Janisol from the exterior, but are uninsulated – a cost-effective choice for interior screens, shopfronts inside conditioned spaces, or any opening where thermal performance isn’t needed. These profiles still benefit from steel’s strength and can be fabricated into various operable or fixed units. (For external applications where insulation is critical, Janisol or Janisol Arte would be recommended; Economy 50 is typically used for interiors or mild climates.)

Work with us and let US produce Your dream windows

We can offer:

• flexible approach 

• short lead times

• excellent quality

• world wide shipping

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One of the reasons Jansen steel windows are so sought-after is their versatility across project types. Portamet’s windows grace a wide variety of buildings – from historic landmarks to cutting-edge contemporary homes – proving that steel windows can enhance almost any architectural style. Here are some key applications and use cases:

• Historic Renovations & Landmarks: Jansen’s slim profiles (especially Janisol Arte) are perfect for replacing old steel windows in heritage buildings, preserving the original sightlines while upgrading performance. Architects can maintain a building’s historic character – thin mullions, true divided lites, arched tops – with modern Janisol Arte windows that provide double glazing and weather tightness. These systems have been used in prestige restorations worldwide, where maintaining authenticity is paramount.

• Modern Luxury Homes & Loft Conversions: Clean, minimalist aesthetics are in high demand for upscale residences and loft-style apartments. Steel windows enable expansive glass openings with minimal framing, ideal for maximizing views and daylight. A thermally broken steel window offers the desired industrial-chic look (slender black grids, for example) without the thermal drawbacks of old steel. Custom configurations like floor-to-ceiling steel French doors, pivot windows, or steel factory-style casements give modern homes a distinctive architectural edge.

• Commercial & Public Buildings: From boutique hotels and restaurants to museums and office buildings, many commercial projects specify steel windows for their blend of durability and style. Steel’s strength allows larger window panels and higher security – great for storefronts, showrooms or ground-floor glazing in public buildings. Jansen systems are robust enough for high-traffic usage (doors in steel frames, for example) and can even provide fire-rated or bullet-resistant solutions for specialized requirements. In trendy hospitality spaces, internal steel and glass partitions are used to create that sought-after loft ambiance. The aesthetic versatility of Jansen profiles – available in any RAL color, stainless steel, or even weathered Corten steel – means they can complement both ultra-modern decor and classic vintage themes.

No matter the application, Portamet ensures that the steel windows we supply are engineered to the project’s needs. Our technical team can produce custom shapes for ecclesiastical or art-deco windows, large-format fixed glass walls for panoramic views, or intricate grid patterns for interior partitions. Jansen steel windows excel in scenarios where standard aluminum or uPVC simply don’t offer the required slimness, strength, or visual impact.

Portamet stands out among steel window manufacturers for our quality, service, and technical capabilities. We not only use genuine Jansen profiles but also bring years of craftsmanship and engineering know-how to every project. Here’s why architects, builders, and owners trust Portamet for Jansen steel windows:

• Authentic Jansen Profiles & Expertise: We are committed to using certified Jansen steel profiles in our production – ensuring you get the genuine Swiss-engineered product with its proven performance. Our team is highly familiar with Jansen’s entire catalog (Janisol, Arte, Economy, etc.) and can recommend the best profile for your needs. This expertise means your windows are engineered correctly from the start, avoiding any mix-and-match issues and guaranteeing the full benefits of the Jansen system.

• Superior Craftsmanship: Steel windows require specialized skills to fabricate and finish. At Portamet, we employ experienced metalworkers and welders who treat each window as a crafted piece. Precise miters, solid welds, and careful grinding and polishing are standard in our process, resulting in clean lines and impeccable corners. Our factory in Gdańsk is equipped with modern CNC machinery and tools specifically for steel fenestration. The result is precision-built windows that fit perfectly and operate smoothly for decades. Every unit undergoes thorough quality checks for alignment, weld integrity, and finish before it leaves our workshop.

• Thermal and Weather Performance: Portamet specializes in thermally broken steel windows, so achieving excellent energy efficiency and weather resistance is a given. We ensure that each window and door is fitted with the correct gaskets, seals, and insulating glass to maximize performance. Whether it’s triple-pane low-E glazing for a cold climate or special solar-control glass for a hot region, we have the know-how to meet project-specific performance targets. Our steel profiles combined with high-quality glazing can achieve Passive House-level U-values in certain configurations, all while retaining the slim aesthetic.

• Design Support & Custom Solutions: Unlike mass producers, we thrive on custom projects. Our engineers collaborate with architects to realize unique designs – be it a one-of-a-kind geometric window or a massive steel-and-glass wall. We offer full CAD/BIM support for detailing connections and profiles, and we can accommodate custom hardware, bespoke mullion layouts, and specialty finishes. Jansen’s systems themselves are very versatile (allowing custom mullions, angles, curved frames, etc.), and Portamet leverages that flexibility to give you exactly what your design calls for. We also provide technical consulting on feasibility, ensuring that ambitious concepts are executed in a safe and lasting way.

• Global Logistics & Installation Assistance: Choosing Portamet means you have a partner experienced in global supply. We handle all packaging and shipping logistics, whether your steel windows are traveling 500 km within Europe or 5,000 km overseas. Each unit is carefully packed, and we work with trusted freight forwarders to manage delivery timelines. For large or complex installations, we can coordinate with local installers or even dispatch our technicians (by arrangement) to provide guidance on proper fitting of the steel frames on site. Our goal is a hassle-free experience from initial quote to final installation.

• Competitive Pricing & Value: By manufacturing in Poland, we offer world-class quality at a cost-effective price point. You benefit from lower labor and overhead costs compared to many Western European or US manufacturers, without any compromise in materials (we use the same Jansen profiles and European hardware). Steel windows are an investment, but Portamet strives to deliver maximum value – our windows combine longevity, performance, and beauty, which translates to long-term ROI for your project. Moreover, our efficient production and B2B approach mean we can accommodate both one-off custom orders and larger volume requests with equal attention to cost optimization.

When you partner with Portamet, you’re choosing a Jansen steel windows manufacturer that aligns top-tier materials with personalized service. We take pride in helping realize architectural visions with products that exceed expectations in form and function.

Let us know if You have any questions.

We are here to assist You with:

• design 
• production
• after sales
• etc

Contact Portamet today to discuss your project or request a quote. As an experienced steel windows manufacturer serving Europe and the USA, we are ready to assist you at every step – from initial design consultation to final delivery. 

Experience the blend of craftsmanship, quality, and performance that our Jansen steel windows bring to residential and commercial projects worldwide. Let Portamet help you create enduring architectural masterpieces with the finest steel window systems. Get in touch with our team now and discover how we can make your vision in steel and glass a reality.