smartshell reno - guaranteed heating costs after the renovation, with us a clear matter.

Prefabricated very simple standard elements form the basis of our modular Verion for small sized building units.

At the end of 2022, Sepp Lorber and Franz Freundorfer started to design a standard element made of lightweight wood wool panels. The base element is a 600 x 2000 mm compartment-forming element that can be blown out with various insulating materials. This is screwed to the old building wall with 9mm thick plywood strips. The windows already contain the outer reveal, which at the same time offers the connection to the HWL plates.

Of course we have a prfab version for bigger builing units as well. Modular Verion and perfan Version are combinable.

Presentation 26th International Passive House Conference Wiesbaden Wolfgang Hasper and Franz Freundorfer

smartshell reno und serielles Sanieren präsentiert am AK61 in Darmstadt

After the founders of smartwin achieved worldwide acceptance in window development with the innovative products of the smartwin family, the window tinkerers are now going one step further towards energy-efficient and economical building shells. smartshell is the perfect addition to the smartwin family: building shell and windows from a single source save your money. Four certificates for wall and building systems are already available at the start of smartshell cooperation. A worldwide network is planned, which will build on the base of existing smartwin partners. We are a strong team, that solves the interface problems on your building and has a good overall result in mind.


Presentation "smartshell reno" from Franz Freundorfer

GFF-Interview with Franz Freundorfer and Wolfgang Feist.


Opaque building envelope

The system is dedicated as an additional external insulation for existing buildings. For the certification it was assumed, that the flor slap is enhanced by a PU-foam insulation. The thermal quality of the walls is improved by an exterior insulation. A plastered wood fiber board is located on the very outside of the new insulationlayer. It is connected to the existing walls via timber beams and punctual anchors. The space in between the old wall and the wood fiber board is filled with cellulose.  
An additional insulation layer outside the existing roof construction in combination with a cellulose infill insulation between the rafters reduces the thermal losses of the roof.


The certification was done with the window smartwin solar, which is a very slim phA-class window with triple 18 mm argon glazing, Swisspacer Ultimate spacer bar with PU secondary seal. A special feature of smatwin solar is, that the reveal becomes part of the windows frame.

Airtightness concept

The airtightness layer in the walls is the improved external plaster. The plaster and the windows as well as other junctions are connected via airtightness tapes. In the roof, an OSB-board at the roomside of the construction serves as airtightness layer.
The boards are connected by an airtightness tape.