ONE-BLOCK party wall

From left to right: Wolfgang Angerer (technician at Wolf Bavaria), Harald Sauter (SWISS KRONO application technician) and Michael Wolf (managing director of Wolf Bavaria)

The highly acoustically insulating ONE-BLOCK party wall

The ‘ONE-BLOCK’ party wall is a highly acoustically insulating, solid timber solution for separating two residential units. Wolf Bavaria and SWISS KRONO developed a solid, dismantlable exposed soundproofing wall comprising acoustically insulating MAGNUMBOARD® OSB and PhoneStar boards with a flexible free-floating core that achieves a very high airborne sound attenuation value of R_W = 66 dB. No additional soundproofing is required. The wall is stackable and can be prefabricated. It is connected using only screws, in other words neither spring rails nor acoustic isolation clips are required.

The components of the ONE-BLOCK party wall are as follows

SWISS KRONO MAGNUMBOARD® OSB

Structural functions
Thickness dependent on fire protection requirements (up to F90-B)
Benefit of direkten Beschichtbarkeit

Phonestar Schalli

Multiply sound insulation and decoupling strip with loose sand
Inhibition of sound propagation across the individual layers

PhoneStar Tri

Highly acoustically insulating, heavy, highly flexible, multiply board with loose sand
Greatly attenuates airborne sound by absorbing harmonics

Wolf mineral wool

Acts as a spring in conjunction with the air layer
Supports free-floating attenuation of airborne sound while increasing the acoustically insulating effect

PhoneStar products meet all sustainability criteria and are therefore suitable for building KfW efficiency houses with QNG seal, which qualify for subsidies in Germany. SWISS KRONO OSB/4, from which MAGNUMBOARD® OSB is made, is also QNG-compliant.

The benefits of the ONE-BLOCK party wall at a glance:

Excellent attention of airborne sound (R_W = 66 dB)
No spring rails or acoustic insulation clips required
A single block only 265 mm thick
Can be prefabricated in the factory
No soundproofing measures required at the construction site
Dismantlable
Qualifies for QNG-based subsidies in Germany

Installation of the party wall with SWISS KRONO MAGNUMBOARD® OSB, PhoneStar acoustic insulation and mineral wool at a construction site (© SWISS KRONO | photographed by Michael Weithe)

Honoured by an Innovation Award at BAU 2023

From left to right: Dionys Ottl (architect and managing director of Hild und K), Harald Sauter (SWISS KRONO application technician), Michael Wolf (managing director of Wolf Bavaria) and architect Veronika Dannheimer (of Dannheimer + Joos Architekten) at the awards ceremony at BAU 2023 in Munich. (© SWISS KRONO | photograph by Schelke Bonnetsmüller)

The ‘Innovation Award Architecture + Construction’ was bestowed on the first day of the BAU 2023 in Munich by the architectural journals AIR and AIT-Dialog in cooperation with Messe München. The jury, comprising a number of prominent architects including Veronika Dannheimer and Dionys Ottl, issues it to honour innovative products, materials and systems for forward-looking construction. The goal is to highlight products and solutions that are particularly well-suited for meeting architects’ needs. When choosing the winners, the jury not only pays attention to functionality and quality of design but also stresses technically intelligent solutions and versatility for a wide range of applications. Out of a field of more than 70 firms with over 100 submissions, Wolf Bavaria and SWISS KRONO received one of four innovation awards for the ONE-BLOCK party wall.

The story behind the idea

While designing a block of flats to be built using wood-based materials, architect Sandra Kuschel of the Hamburg-based real estate developer Kuschel & Fricke Immobilien was looking for a way to achieve a high level of acoustic insulation between the units. Via her construction supervisor, Markus Bartels, she got in touch with the company of 3B TEC, a licensee and producer of the SWISS KRONO MAGNUMBOARD® OSB solid timber construction system. 3B TEC convinced her of the advantages of MAGNUMBOARD®: a high level of prefabrication, lean walls, easily added fire protection, and the ability to directly coat or cover it. The only item on her wish list that it didn’t meet was enhanced acoustic insulation. “MAGNUMBOARD® is a really great product that we were very interested in working with,” says Kuschel. “We were especially excited by the fact that it can be directly covered with plaster, paint, wallpaper or tiles. But having to mount plasterboard on top of the walls to provide acoustic insulation would have eliminated all of these advantages while greatly increasing costs. So we asked whether integrate acoustic insulation could somehow be directly integrated while still keeping the wall as thin as possible.” The experts of Kuschel & Fricke then went to work with 3B TEC. They brainstormed, developed ideas, tried out different board thicknesses and came up with various designs.

The outcome of all this effort was the ONE-BLOCK party wall. Those involved had set themselves the goal of achieving an acoustic insulation value of at least 60 dB. Wolf Bavaria and SWISS KRONO submitted their brainchild to ift Rosenheim for testing, where it actually exceeded their target with a value of RW = 66 dB!

Involved in development and implementation:

Kuschel & Fricke Immobilien GmbH & Co. KG, Bergstedter Markt 1
22395 Hamburg, www.kuschelundfricke.de
Wolf Bavaria GmbH, Gutenbergstraße 8, 91560 Heilsbronn, www.wolf-bavaria.com
3B TEC MagnumBoard GmbH, Gottlieb-Daimler-Straße 17, 14974 Ludwigsfelde, www.magnum-board.de
SWISS KRONO TEX GmbH & Co. KG, Wittstocker Chaussee 1, 16909 Heiligengrabe, www.swisskrono.com/de