Consistently flush-mounted

How switch design becomes an integral part of the interior design

The puristic design is increasingly gaining acceptance in modern interior design. Flowing, smooth transitions between surfaces and components are in demand. Manufacturers of doors, windows, fittings or luminaires already have solutions that take account of the requirements of architects and interior designers: Door frames can be installed flush, spotlights become technically integrated in the ceiling without visible material transition. However, a concept that enables consistently flush mounting in series was previously lacking in the electrical installation. The JUNG company accepted this challenge and presented its LS ZERO switch design for the first time at the Light+ Building exhibition in March 2016.

Challenges and approaches
The objective for the development of LS ZERO was to create a design based on the proven LS 990 flat switch that "submerges" flush into the wall. The solution should also be transferable to furniture to also be able to continue the implementation specially for kitchens and bathrooms. Developing an easily understandable installation concept based on standards was just as important as the format and functional aspects. It was crucial to gain understanding and knowledge about the work practices of other trades and to take appropriate account of these for the design of LS ZERO. In doing so, international installation standards and practices have been taken into account to ensure the mounting on the different wall boxes.

Thorough research as basis
The development of LS ZERO was preceded by extensive market research. On the one hand, the solutions of various market players in the installation environment were analysed and assessed. On the other hand, architects, planners and interior designers as well as electrical installers, painters and plasterers as representatives of the involved trades were interviewed in a wide-ranging survey.

The transition from the design frame to the wall represented a major task in this phase. Because the usual electrical installation after removal of the plaster cover shows an undefined edge that can only be covered by a wide frame. In a second survey, the concept ideas were evaluated so that finally an approach favoured by all respondents stabilised. Based on the LS 990 switch design, this concept envisaged a plastering adapter that could be installed in the plaster layer in combination with the different country-specific wall boxes and should form a firmly bonded connection with the various plaster materials. For the dry wall installation, the first board layer provided the necessary space, and for the implementation in furniture installation, the appropriate contour could be applied using mechanical machining. In order to guarantee a visually seamless transition and a uniform gap size, the inner edge of the plastering adapter should form the termination for the switch (frame).

From the idea to the solution
After the materials for plastering and filling for masonry and dry wall had been defined, the research started for the appropriate material for the new plastering adapter to be designed. Jung asked experts for the "materials" subject about specific characteristics, processing options etc. The individual materials passed through diverse test series to be included in the shortlist afterwards if applicable. The objective was a material that functioned both in masonry as well as dry wall in order to keep the logistics effort for planners and installers for the order and on-site at the construction site as small as possible.

It quickly became clear that the tested plastics could not provide adequate bonding to the plastering and filling materials and thus the inner edge of the plastering adapter remained visible in the plastered wall. The JUNG project team also assessed the dimensional stability as inadequate. A ceramic material was finally found after further extensive material research that provided all necessary bonding characteristics and could be installed in the wall "as if from the same mould". Finally, a combination of ceramic and plastic was selected.

The requirements profile for the mounting of the new plastering adapter and the specification for its height emerged from this agreement. Because this dimension – derived from the thickness of a commercially available plasterboard and the minimum amount of plaster to be applied – creates the further requirement for standardised implementation in dry wall and masonry. It also became clear that subsequent alignment of the plastering adapter in the plastered wall is advisable to guarantee a perfect transition. For this reason, JUNG also developed a placeholder made of polystyrene ("plastering aid") that fulfils various tasks depending on the mounting surface. For the mounting in masonry, this plastering aid takes over the function of a plaster cover so that the necessary space for the flush-mounting alignment of the plastering adapter is produced after the plastering. For dry wall mounting, the plastering aid is used as stencil for marking the recess in the first board layer.

Three types of mounting – three simple processes
The flush-mounting installation of LS ZERO in masonry, dry wall and in furniture installation proceeds with little effort. Using plastering adapters, a material firm bond with the plaster is achieved in masonry and dry walls; in the furniture installation, LS ZERO and furniture are also visually seamless. Clear videos for the three types of mounting can be found at

Masonry mounting steps
  1. Clearance for wall box, e.g. using drill bit. In doing so, take into account that the wall box should be plastered flush with the wall (otherwise plaster layer must be applied thicker by the amount of the protrusion).
  2. Centre wall box on the wall.
  3. Align plastering aid centrally using markings over the wall box and tack on the wall.
  4. Apply plaster in the usual way and depending on requirements. In doing so, the plastering aid specifies the plaster thickness.
  5. After drying, remove the plastering aid and clean the space.
  6. Now coat the plastering adapter on the rear side with plaster and bring it into the space produced. In doing so, ensure that the recesses and screw holes of the plastering aid match those of the wall box. Now align the plastering adapter and make it flush with the finished plastered wall.
  7. After drying, the remaining intermediate space is filled with plaster and excess plaster is removed. The plastering adapter is now flush in the wall.
  8. After grinding the surface, the plastering adapter is embedded seamlessly in the plaster layer and is visually part of the wall. The inner edges of the plastering adapter form the finished termination for the LS ZERO design frame.
  9. The electrical installation and the installation of the design covers are performed as usual.
Dry wall mounting steps
  1. Position and process the dry wall board in the usual way. A double board layer is required.
  2. Clearance for wall box, e.g. using drill bit.
  3. Centre wall box on the wall.
  4. Align plastering aid centrally over the wall box using markings and mark all round to mark the size of the clearance.
  5. Now cut around the marked area with a cutter and a bar and remove the first board layer.
  6. Fasten wall box on the board layer below as usual.
  7. Align plastering adapter in the clearance and fasten to the box using the box screws.
  8. Now fill the remaining intermediate space with filler and remove excess filler. The plastering adapter is flush in the wall.
  9. After grinding the surface, the plastering adapter is seamlessly embedded in the dry wall board. The inner edges of the plastering adapter form the finished termination for the LS ZERO design frame.
  10. The electrical installation and the installation of the design covers are performed as usual.

Furniture installation
For the furniture installation, the contour of the plastering adapter is applied in the respective part using a milling machine. The use of the plastering adapter is not necessary in this case. All required drawing data are available for download at The mounting afterwards is performed as standard; in doing so, the LS ZERO design frame is directly in the clearance and forms a flush-mounted transition to the furniture.

Alternative: 3 mm installation height
Alternatively, LS ZERO is also available in a version with 3 mm installation height. This is suitable, for example, for walls with wallpaper / wall coverings. The design frame here minimally overlaps the wallpaper edge and thus provides visual harmony. This version is also suitable for plaster or plasterboard with a thickness of 12.5 mm.

The concept is succeeding
Almost nine months after market launch, the positive feedback from the market shows that the intensive preparatory work by JUNG for the development of LS ZERO was the key for success. The first reactions already during the Light + Building exhibition were clear: "successful, coherent design", "easy mounting" to "That is so simple, it must already exist!". This is also followed by the feedback of specialists who have installed LS ZERO since then. Awards such as the Plus X Award, Iconic Award and Architecture + Technology innovation award also demonstrate that the new JUNG switch design is outstandingly positioned on the market.

With LS ZERO, JUNG has succeeded in the consistent implementation of a flush-mounting switch design. As well as the new type of appearance and scope of functions, mainly the well-thought out concept is impressive. Thus not only the requirements of architects and interior designers are met but also the cross-trade processes for the installation speak for themselves in their coherence and simplicity.

Author: Oliver Stuke, Product Area Manager, Electromechanical / Design at Albrecht Jung GmbH & Co. KG