Dorsis Fortius

Exceptional frameless doors for beautiful homes

Imagine a full-height interior door with a concealed door frame in your unique modern house.

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Frameless door made by Angelbau Dorsis. Flush door panel in white, installed in a high-end luxury residence. Interior design combines European white oak hardwood floor and polished onyx wall panels.

Why Dorsis Fortius

Beautiful design meets outstanding engineering

Frameless doors by Angelbau Dorsis in floor-to-ceiling, header, transom, and angled versions.

Floor-to-ceiling door

Full-height filo muro door Dorsis Fortius goes all the way to the ceiling. It's an inexpensive way to make every room look taller instantly.

White modern floor-to-ceiling frameless door made by Angelbau Dorsis.

White or color

Trimless white doors are the favorite choice for contemporary interiors. Dorsis interior doors are painted in a RAL or NCS color of your choice. Explore our high gloss finish.

Frameless doors by Angelbau Dorsis are supplied with flush door panels in various finishes including paint, wood veneer, high gloss white or color paint, laminate or wallpaper.

Wood veneers

Bring some wood to your modern interior. From modern European White Oak to exotic woods, you'll find the right wood veneer for your new doors.

Frameless doors with different size glass door panels.

Glass panel door

Introduce light to your hallway or pantry. Dorsis Fortius can accommodate a set of glass panels. Choose clear glass, translucent satin glass, bronze glass.

Angelbau Dorsis concealed door frame in many white finishes as well as custom powder-coated finishes.

Door frame finishes

Your concealed door frame is powder-coated in your choice of RAL color. Choose the same white color as your door, or go with gray/black for veneer doors.

European-style door lever handle in chrome with a white insert made by M&T. Designed to match white frameless doors by Angelbau.

Designer door hardware

Choose from one of our 1000+ door handles, including the invisible No-Ha handle. Not only are our door handles beautiful pieces of design, they are also highly engineered products.

White concealed door hinges by Anselmi, a Simonswerk company. Used for frameless flush doors made by Angelbau Dorsis.

Concealed door hinges

Dorsis Fortius concealed door frames are equipped with 3-way adjustable Anselmi concealed hinges or Tectus concealed hinges made by Simonswerk.

Aluminum extrusion profile for modern frameless doors with an integrated white silicone gasket for sound insulation.

Sound insulation

To increase sound insulation, your Dorsis Fortius concealed door frame comes with a silicone gasket embedded in the door frame. In white, gray or black.

A magnetic door lock with a magnetic striker embedded in the Angelbau Dorsis frameless door.

Dorsis magnetic lock

High-end design with an invisible strike plate and invisible latch bolt. Latchbolt stays retracted until the door fully closes.

Adjustable integrated tensioning rod for flush door panel icon.

Tall door straightener

To achieve a perfectly flush look for years to come, every 8+ ft tall Fortius door comes with a built-in adjustable tensioning rod.

Any size, finish, design

Concealed doors made for North America

Full-height doors as well as floor-to-ceiling windows have been a go-to choice for leading modernist architects like Ludwig Mies Van der Rohe. Flush interior doors with concealed door frames are the pinnacle of modern architecture in the United States, a trend pioneered in Europe.

We manufacture custom frameless doors as part of our exclusive door system which includes trimless pocket doors and flush recessed baseboards.

  • Custom sizes to fit any opening
  • Custom finishes
  • Stainless steel, black, bronze, or white hardware
  • Fully integrated with pocket doors, barn doors, baseboards
Invisible door jamb on Fortius 52 white interior inswing door with flush transom. Terrazzo floor in hallway. Recessed ceiling round LED light.

Solid core construction

Designed for durability and beauty

Flush solid core door panel for Dorsis Durus and Dorsis Fortius frameless doors.
Dorsis solid core door

Each panel is a 5-ply (painted doors) or 7-ply (veneer door) solid core door sandwich. Engineered to support tall doors up to 137" without warping and to accommodate additional cladding and custom panelling.

Ultra smooth finish

The skin of the Dorsis door is an ultra smooth ¼" (6 mm) MDF board providing durable basis for high-end smooth finish – which you won't find in common dual MDF assembly solid core doors.

Excellent acoustic performance

Each door slab we supply is using double-layer lightweight MDF boards to ensure both rock-solid stability for tall doors and excellent acoustic performance, so that you don't hear sounds.

5-layer durable paint

Dorsis provides painted doors because site-painted doors never match the quality of factory finish. For most projects we use 20% gloss, with an option for high-gloss. We use 5-layer polyurethane-based paint process.

Adjustable straightener

Your door slab will have a vertical tensioning rod to allow serviceability. Should the door get out of plane, you can adjust the tensioning rod and bring the door back to plane within a few days.

Keyless entry with smart door locks

Modern garage-to-house door Dorsis Fortius is compatible with keyless access systems and electromechanical locks.
House-to-garage door

The entryway between the house and garage is usually the most used doors in the home. To make entry easy for all household members, we can optionally equip this door with an electronic or electromechanical lock.

Keyless entry for modern garage-to-house door with RDIF, Bluetooth, NFC and Wi-Fi compatibility.
Keyless entry

A Dorsis concealed door with the Assa Abloy EL560 electromechanical mortise lock has handles on both sides: the outside handle is electrically controlled (by keypad, RDIF card or tag reader, or iPhone via a Bluetooth sensor), the inside handle opens the lock always.

Loxone NFC Code Touch keypad for keyless entry, compatible with modern garage-to-house doors such as Dorsis Fortius.
Integrate access systems

Assa Abloy EL560 electro-mechanical mortise lock is designed to work with smart home automation systems such as Loxone or fingerprint scanner access systems such as ekey biometric systems.

Panic function unlocks the lock in direction of egress in case of emergency.
Panic lock function

Set up your Assa Abloy EL560 to unlock a locked door via the inside handle where the mortise lock pulls the long bolt back and also unlocks the flip latch (panic function). The lock locks automatically when the door closes (automatic locking).

Modern panic bar Hewi for upscale modern offices, compatible with frameless doors with concealed door frame Dorsis Fortius.
Panic bar for exit doors

For commercial applications, you can choose to equip the Dorsis Fortius door with a panic bar (such as HEWI Bar System 111/162) to allow free egress in case of emergency. The inside panic bar always operates and the outside handle is controlled and activated on signal from your access control system.

Inswing and outswing doors

The Dorsis Fortius concealed door jamb system allows you to put your flush-with-the-wall door in different wall assembly configurations. While drywall remains the most popular, you can use the Fortius concealed door jamb system with other materials and wall claddings.

Exterior View of Inswing Door

Hidden door frame, exterior side of the flush-with-the-wall door with wood veneer finish, in a 2x4 wood stud wall.

Concealed door frame

The hidden door frame can be installed in all common wall assemblies.

Wood stud framing

  • 2x4 stud wall
  • 2x6 stud wall
  • 2x8 stud wall

Steel stud framing

  • 3-½" metal stud wall
  • 3-⅝" metal stud wall
  • 4" metal stud wall
  • 5-½" metal stud wall
  • 6" metal stud wall

On the flush side the door frame can receive a ½" drywall sheet which you can also combine with ⅝" drywall sheets.

Interior View of Inswing Door

Hidden door frame, interior side of the flush-with-the-wall door with wood veneer finish, in a 2x4 wood stud wall.

Custom wall assembly options

You can easily integrate the Fortius concealed door frame with the Dorsis Linus flush baseboard.

On the interior side you can use ½" or ⅝" drywall/sheetrock.

Product specifications

Documentation & CAD data

We will gladly assist you with your planning with the Dorsis Fortius invisible doors and provide your project architect or designer with interior door shop drawings for inclusion in your Construction Documents (CD).

Fire Door Documentation

Dorsis Fortius EI30 is a fire-rated frameless door with a 30-minute rating. Tested as EI/EW 30 DP3-C.

Dorsis Fortius Invisible Door
Door height
72-137 ¾"
Standard: 6’, 7’, 8’, 9’, 10’, 11’
Door width
Standard: 28", 30", 32", 34", 36"
Panel thickness
2” (52 mm) - any height
1 ¾" (40 mm) - option only for shorter 6’ & 7’ doors
Frame color
RAL 9003, RAL 9010, RAL 9016 (Standard)
RAL Classic K7 System: 215 Colors (Optional)
Door panel finishes
Wood veneer
Laminate (CPL / HPL)
Door panel composition
Solid core
Solid core acoustic
Honeycomb core
Custom panels & finishes
Wood wall paneling, cladding & slat panel solutions
High-gloss or deep matte paint
Micro-topping (thin layer of concrete or plaster)
Wall tiles (large format, porcelain, natural stone)
Glass or back painted glass


When you buy a modern interior door from Angelbau, you always get a complete, ready-to-install door unit. Unlike a traditional pre-hung door, our door always includes all of the hardware components you have selected.

Starts at
per a complete frameless door unit