The local authority in Bad Kreuznach selected Finstral fitted frames when refurbishing the windows in its large administration building, containing 200 offices.
The windows could therefore be replaced very rapidly and reliably, with the special bonus of being able to fit the windows without problems while the premises were still occupied by office workers, all according to an exact timetable.
As with many administrative buildings constructed in the 1970s, time has left its mark on the structures used by the Bad Kreuznach local authority. The numerous aluminium windows in the five-floor complex, which dates from 1973, in particular showed clear signs of age.
Defective hinges and fittings, ill-fitting insulation windows in places and outdated constructions in terms of energy conservation all meant that the refurbishment of the 1,400 m² glazed area was an urgent necessity.
But replacing windows in old buildings can be a technically delicate (and certainly complex and dirty) operation. The district authority therefore decided to use the fitted window frames produced by the South Tyrolean manufacturer Finstral.
The trick during assembly works was that the Finstral fitted frame was simply installed over the existing window frames. The old windows are thus removed and replaced but the frames remain in the wall, leaving the masonry unaffected.
There was practically no damage to the reveal, window sill, plasterwork, wallpaper or façade.
“The windows were exchanged during office hours, with no dirt or dust”, says Jens Borchardt of the Bad Kreuznach board of works: a major bonus for the 245 or so staff employed in the nine different offices and agencies there, as all furniture, documentation and technical equipment such as phones and computers could remain in place during refurbishment.
There was no need for awkward temporary solutions for the workplaces concerned, while burdensome office moves within the building and lost working time were minimised.
Assembly of the new windows in the administration building was carried out by the Manfred Schug Metallbau GmbH company of Idar-Oberstein. First the old window sashes and fixed glazing were completely removed along with all seals and fittings.
The old aluminium structure was then fully packed with heat-insulating material in order to ensure thermal separation and avoid possible cold bridges.
The fitted frames, which consist of a thermally insulated PVC frame, were then installed from the inside, followed by the mounting of the new sashes and fixed glazing areas using triple insulation glass. The last step was to fit the seals and external facings.
Refurbishment during working time
Borchardt is pleased: “Thus far the change has been very quick, smooth and clean. There have been no holdups in the administration’s workflow.” A standard window can be replaced in around one hour.
This refurbishment method means that each window can be changed room by room according to a schedule, minimising the problems associated with building sites – restrictions on room usage, noise, dirt – while allowing the building to be secured overnight.
The fitted frames can be combined with all Finstral systems. The district authority thus selected two-tone windows – white inside and brown outside - with an aluminium exterior facing.
“This combination offers weathering protection in combination with more economical PVC profiles”, says Jens Borchardt. The original façade design too is preserved, while the interiors are now brighter.
“The slender frames of the Finstral windows also means that a minimal glass area is lost”, he adds. The changes in the refurbished sections can already be seen: as well as high thermal insulation, the new windows also offer improved noise insulation, greater ease of use, more protection against break-ins and very good airtightness and protection against driving rain.
Suitable for every building situation
The principle of the fitted frame works in every building situation and for any material, whether for wooden, aluminium, PVC or composite windows. As the façade and masonry remain unaffected, these frames are also ideal for the refurbishment of insulated façades.
The joints used by Finstral fitted frames are certified by the Institute for Window Technology (ift) in Rosenheim, Germany. The assembly process is shown in a short film on the Refurbishment page.