Thermal insulation
Thermal insulation

Ud up to 0.87 W/(m2K)

Sound reduction
Sound reduction

up to 34dB

Security
Security

up to RC2

Locking
Locking

Multi-locking

Construction depth
Construction depth

93mm

Test Certificate Available

bimobject.com

The Internorm AT 535 aluminium front door delivers a sharp, contemporary appearance with a completely flush door sash and square-edged design on both the inside and outside. Its clean geometry makes it especially suitable for modern architecture where crisp detailing and a seamless finish matter.

Beyond appearance, the AT 535 is engineered for practical everyday performance. The 3-chamber frame profile with an insulating foam core helps achieve strong thermal insulation, while the standard multi-locking system supports a high level of security. Sound reduction reaches up to 34 dB, helping reduce external noise and improve indoor comfort.

The system also offers a wide range of design possibilities, allowing the door to be customised to suit both the architecture of the property and the preferences of the homeowner.

Features:

  • Material: Aluminium
  • Design: Entire door sash flush with a square edge towards the frame on both sides
  • Profile system: 3-chamber frame profile with insulating foam core
  • Thermal insulation: Ud up to 0.87 W/(m²K)
  • Security: Multi-locking system with security up to RC2
  • Sound reduction: Up to 34 dB
  • Construction depth: 93 mm
  • Customisation: Wide range of options and bespoke design choices available

Benefits:

  • Clean architectural design with a flush internal and external appearance
  • Strong thermal performance for improved comfort and energy efficiency
  • Reliable security with robust multi-point locking
  • Good acoustic insulation for quieter interiors
  • Highly customisable to suit different entrance styles
  • Durable aluminium construction built for long-term performance

Ideal for homeowners, architects, and developers looking for a contemporary aluminium front door with flush styling, dependable insulation, and strong security. The AT 535 suits projects where clean design, durability, and practical performance all matter.

  • Spec Sheet
  • Colours & Surfaces
  • Obscure Glass Options

Recent Work

Working closely with architects, builders, and homeowners, we’ve delivered systems that combine thermal efficiency, modern aesthetics, and long-term durability—across private residences, sustainable developments, and architect-led designs.

Expert Advice & Insights

Explore detailed material comparisons, tailored installation advice,
and practical maintenance tips to keep your windows and doors performing at their best.

A Window Isn’t Just a Window: A Deep Look Into How Modern Glazing Really Works

A Window Isn’t Just a Window: A Deep Look Into How Modern Glazing Works

An in-depth guide to modern glazing. Explore the physics of slimline frames, why showroom displays look different from reality, and how triple glazing and proper installation define home comfort.

By AT-ECO, on March 11, 2026
Read more
The Complete Guide to Choosing Low-Carbon Windows and Doors

The Complete Guide to Choosing Low-Carbon Windows and Doors

Learn how to choose sustainable windows and doors for your home. This guide explains operational and embodied carbon, from recycled materials to energy-efficient design, and what to ask your supplier.

By AT-ECO, on September 8, 2025
Read more
Smart Home Technology in the UK: How Windows and Doors Are Getting Smarter

Smart Home Technology in the UK: How Windows and Doors Are Getting Smarter

Discover how smart home systems are revolutionising windows and doors for UK homeowners. From automated blinds to smart locks, learn how this technology enhances security, convenience, and energy efficiency.

By AT-ECO, on September 8, 2025
Read more

New Product Alert: HF 520 & AT 525 Now Available

We’re excited to introduce the new HF 520 Studio timber-aluminium window with I-tec Glazing to our premium Internorm range. Perfect for both residential and commercial projects, these new additions are now available to explore at our Brasted showroom.

Build It Live South East

Yes, we recommend booking an appointment to ensure personalised service and availability. You can schedule your visit by filling out our contact form or emailing us at [email protected].

During your visit, our team will guide you through our range of premium window and door systems. We’ll answer your questions, help you explore customisation options, and assist in finding the perfect solution for your project.

Absolutely! Bringing your project plans or drawings can help our team better understand your needs and provide tailored recommendations.

Our knowledgeable team is here to help. Whether you need advice on materials, styles, or energy efficiency, we’ll guide you through the process and ensure you make an informed decision.

Ready to Upgrade Your Garage Door?

Book your free home survey today and discover the perfect fit for your property.

TOP