minimal windows

Minimalist design sliding windows and sliding doors
– transparency for innovative architecture!

 Modern contemporary architecture - pared down to the essentials!
Clean lines, balanced proportions and one element which plays a very particular role - light.
Whether an exclusive villa, detached house, apartment or business complex, open interiors and maximum daylight admission with unobstructed views to the outside
are high on the list of priorities for today’s building clients.

minimal windows Keller window frameless

the frameless sliding window design

The desire for design and exclusivity is more than met by KELLER’s premium sliding and fixed window system -  minimal windows®. The frame profiles are pared back to the minimum and can be fully integrated into the floor, walls and ceiling. Only the slimline leaf profiles with 21 or 26 mm facing width are visible. Up to 98% of the area is therefore glass.

Window areas of up to 12m² can be achieved in sliding doors and up to 18m² in fixed windows. The sliding window system allows heights of up to 4.5 m. This equates to completely frameless transparency.




Frameless design sliding door


The variety of system configuration options ensures a degree of practical flexibility which leaves nothing to be desired. Up to four-track sliding systems, glass-to-glass inside and outside corners, floor, ceiling and wall-flush installation and wall-inlets into which sliding elements disappear completely into the brickwork are all possible. The floor area is free of bothersome thresholds and thus barrier-free. It creates a seamless transition from inside to outdoors.

Sliding door frameless barrier-free flush

easy-action operation

High-performance tracks and rollers in stainless steel guarantee easy-action manual operation, high operating safety and durability. You can opt alternatively to have the sliding elements, which can weigh up to 1000 kg, electrically driven.  This guarantees maximum operating comfort.

Sliding window rails frameless stainless steel

minimal windows®

The large-scale, frameless double-glazed sliding windows and doors in insulating glass allow comfortable, easy-action and silent opening and closure of the thermally-broken transparent surfaces. This is a decisive plus for ease of use on a daily basis. The facing width of the intermediate profiles is just 21mm.

  • Maximum leaf size up to 8.5 m² (fixed lights up to 18 m²)
  • Window profile facing width 21 mm
  • Maximum leaf height 4.0 m
  • Maximum leaf weight 500 kg
  • Single or Double glazed in insulating glass or HeatMirror® glass in thickness up to 34 mm
  • Energy efficient Uw ≥  1.10 W/m²K
  • 1 to 4-track systems, glass-to-glass corner solutions, solid glass corners and wall inlets for sliding leaves
  • Threshold and barrier-free
  • Electric motors with total weight of up to 2,000 kg
  • Burglar-resistant according to WK2 (RC 2)



Sliding window insulation glass frameless without threshold

minimal windows®4+

The 4+ version of the frameless sliding window is the highly-insulated triple-glazed variant. It is ideal for the low energy and passive house standard.
With modern insulated glass windows it is possible to achieve Uw values of 0.80 W/m²K.

  • Maximum leaf size up to 12 m² (fixed lights up to 18 m²)
  • Leaf profile facing width 26 or 34 mm
  • Maximum leaf height 4,50 m
  • Maximum leaf weight 1,000 kg
  • Triple-glazing with insulation glass or special glass
    up to 56 mm glass thickness
  • Energy efficient Uw  ≥ 0.70 W/m²K
  • 1 to 3-track systems, glass-to-glass corner solutions, solid glass corners and wall inlets for sliding leaves
  • Threshold and barrier-free
  • Electric motors with total weight of up to 2,000 kg
  • Burglar-resistant according to WK2 (RC 2)
  • Suitable for use in low-energy and passive houses




minimal windows sliding door triple insulating glazing
Glass façade minimalism glass front

minimal windows® highline

Concentrated minimalism

Aesthetics, combined with high performance features communicate the clean minimalism of our system glass façades. All elements are intrinsic components in modern architecture.

The system glass façade profiles between the two storeys comprise insulated, concealed prone aluminium frame profiles and are ideal wherever minimal profile facing widths and maximum window height are required.

The flush-fitting or offset-surface grass facade can be combined on request with slimline design sliding doors and is the perfect solution for high-quality double-glazed residential and commercial buildings.



Glass front glass façade passive house

minimal windows®4+ highline

The minimal windows®4+ highline concept features striking sleek elegance and unique façade configurations. Clear, precise lines dominate while the glass surfaces are open and inviting. Architectural forms create a strong look and offer an unimpeded view. The open architecture allows occupants to focus on the space.

This floor-to-ceiling premium glass façade comprises highly-insulating triple glazing. The flush- or offset surfaces of the glass façade correspond to energy-efficiency requirements in the low energy and passive house standard.



Glass front glass façade architecture design

More information and technical documentation on the special product website.