Dorsis Fortius 52

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 Fortius 52

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. 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.

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.

Product specifications

Durus 45 frameless door


Up to 7'10" (2400 mm)


18 - 39" (450-1000 mm)


Powder-coated frame in RAL 9003 White (Standard)
Any RAL color (see RAL K7 Classic)


Solid core 1 ¾" (45 mm)


1000+ paint color options (RAL and NCS palettes)
200+ wood veneer options
200+ CPL or HPL laminates


solid core sandwich (acoustic)

Fortius 52 frameless door


Up to 11' (3500 mm)


18 - 39" (450-1000 mm)


Powder-coated frame in RAL 9003 White (Standard)
Any RAL color (see RAL K7 Classic)


Solid core 2" (52 mm)


1000+ paint color options (RAL and NCS palettes)
200+ wood veneer options
200+ CPL or HPL laminates (scratch-resistant)


solid core sandwich (acoustic)


high-gloss or deep matte paint
wallpaper (preparation)
micro-topping (concrete)
wall tiles (large format, porcelain, natural stone)
glass or back painted glass


½" (12 mm) additional cladding for inswing doors
5/16" (8 mm) additional cladding for outswing doors

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.

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.

The wall assembly diagram shows the Dorsis Fortius frameless door in inswing and outswing configurations. The concealed door frame is recessed in drywall and one side of the door is completely flush with the wall.


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

Documentation & Tech specs

Frameless doors have different R.O. requirements compared to standard traditional doors. Rough opening for Dorsis Fortius 52 and Dorsis Durus 45 is 2 ⅜" larger around the perimeter of the frame, except for full-height doors.

Common door sizes
Standard door (with header)
Floor-to-ceiling door
Clear passage
Rough Opening Size
Rough Opening Size
32" x 84"
36 ¾" x 86 ⅜"
36 ¾" x 84"
34" x 96"
38 ¾" x 98 ⅜"
38 ¾" x 96"
36" x 108"
40 ¾"x 110 ⅜"
40 ¾" x 108"