HISTORY OF Keller Minimal Windows by AluK

Conservatory and window construction: the quest for perfection and aesthetics!

Keller minimal windows® from Luxembourg is the leading system manufacturer for design sliding systems. These innovative, virtually frameless sliding windows and doors are installed in particular in higher-class private and commercial buildings.
Keller Minimal Windows by AluK has gained international recognition as a manufacturer of individually designed, exclusive GLASSHOUSE® home conservatories.
Keller Minimal Windows by AluK manufactures on a production area of 8,400 m² in Troisvierges, Luxembourg. Dreams made of aluminium and glass are presented on an exhibition area of more than 2,000 m².
Listed below are the milestones in the company history which mark the transformation from an art metal worker to developer, manufacturer and supplier of modern conservatories, innovative sliding window, fixed window, and pivot door systems




Keller Minimal Windows® joins the AluK Group

Keller Minimal Windows® has been acquired by AluK, a global leader in the design, engineering, and distribution of aluminium windows, doors, and façade solutions.

More info



Opening of the redesigned showroom in Troisvierges (L) with numerous exhibits of windows, doors, conservatories, sliding and solar protection systems in a realistic installation situation. 121 employees


Development of the site in Pilisvörösvar (HUN).
Extension of the product range by the variants wood and wood-aluminium windows and doors.
Establishment of the KELLER SOMENA branch in Dubai.


Presentation at BAU of an innovative KELLER minimal windows® 6m high sliding element, open corner solution with closing sequence control.


After more than 34 years of success story, Norbert Keller, founder, regulates the succession planning and future of his company through the introduction of a Luxembourgian business partner. The management responsibility of the company was transferred with effect from August 1st, 2014 to Serge Niederkorn (in the middle), who will continue to lead the company as Chief Executive Officer. Norbert Keller (right) will remain with the company. In the future, he will focus even more on product and business development. Jörg Heinemann (left) will continue to lead the Sales Department as Managing Director Sales & Marketing.

Opening of the KELLER Competence Center. This is a completely new building with offices and conference rooms for the advising of our customers and for the reception and training of international business partners.
Development of KELLER minimal windows® highline. 103 employees.


Presentation of the new highly insulated premium product line - KELLER minimal windows®4+ - at BAU in Munich.


In response to growing demands for energy-optimised window systems, the company develops the KELLER minimal windows®4+ premium sliding window for the low-energy standard and it is certified in 2012.


The KELLER minimal windows® sliding window system and the KELLER GLASSHOUSE® are presented at BAU in Munich. KELLER is finalist with both products and the “Innovationspreis für Architektur und Bauwesen” (Innovation Prize for Architecture and Construction) in the category “Products of high architectural quality”. 83 employees.


The combination of the KELLER minimal windows® minimalist sliding window with the typical flat roof of the KELLER ORANGERIE® creates a completely new and innovative concept for home conservatories: the KELLER GLASSHOUSE®. 85 employees.


KELLER AG develops the high-tech KELLER minimal windows® sliding window and becomes system manufacturer for this minimalist sliding and fixed window system. 80 employees.


KELLER is a finalist in “Company of the year" in Luxembourg, organised by Ernst & Young. 70 employees.


The KELLER ORANGERIE Elegance® is presented at BAU in Munich where it attracts plenty of international attention and recognition. The production halls at Troisvierges in Luxembourg are extended to 7000m², the showroom and outdoor display area to 2000m². 66 employees.


The KELLER ORANGERIE Elegance® is launched at the trade fairs BATIBOUW in Brussels and at FOIRE INTERNATIONALE in Luxembourg where it thrills both the trade and the public. The business partner network is further expanded. 69 employees.


The development of an all-new concept in home conservatory construction takes on a concrete form: The KELLER ORANGERIE Elegance®. A world-first, which helps KELLER to break through on a worldwide scale and which sets a new standard in home conservatory construction. 62 employees.


The existing production centre is too small and has to be expanded. Amongst other things a new 1000m² consignment hall is built. 58 employees.


The IMPERIAL and AVANTGARDEN ranges are particularly successful and set new standards in modern conservatory construction and building. KELLER takes the first steps to building a European sales network. 37 employees.


KELLER AG receives the sought-after label “Made in Luxembourg”. 27 employees.


KELLER develops its own profile system with improved thermal break and completely new possibilities in home conservatory construction. 22 employees.


Norbert Keller himself becomes a manufacturer of conservatories to better meet the requirements of modern architecture and the expectations and demands of its users. 20 employees.


Norbert KELLER AG is founded in Luxembourg. The new site offers completely new display and manufacturing opportunities. The company employs 12 people at the start.


He expands his activities to include the sale of steel and aluminium conservatories. At this point he is working for other manufacturers.


Norbert Keller founds his company in Schönberg - Belgium. As an art metal worker he produces staircases, railings and ironmongery for the building industry.

Choose your language: