H1 HIGH-RISE RESIDENTIAL BUILDING, ZWHATT AREA, REGENSDORF, 2019-2025

Rammed earth floor, design

Venue: H1, Zwhatt Areal, Althardstrasse 60, 8105 Regensdorf
Built: 2024-2025
Material: Rammed earth floor
Partners: Boltshauser Architekten AG, Pensimo Investment Foundation, SEFORB, Schnetzer Puskas Ingenieure AG, Keller Unternehmungen
Photos: LEHMAG, Cynthia Ruf

CONSTRUCTION RAMMED EARTH FLOOR
As part of the Zwhatt site in Regensdorf, a high-rise residential building with a hybrid load-bearing structure has been under construction since 2019. The H1 project, designed by Boltshauser Architekten AG and developed in cooperation with the Pensimo investment foundation, combines timber, concrete and clay construction in a latest-generation high-rise building. The structural design was carried out by SEFORB s.à r.l. and Schnetzer Puskas Ingenieure AG.

The building is constructed as a timber-concrete hybrid: The access core, ceilings and base floors are made of concrete, while the façade elements, beams and columns are made of timber. This construction method reduces CO₂ emissions by around 670 tons over the 60-year lifespan and also optimizes the indoor climate and construction time. The photovoltaic system integrated into the entire façade and roof generates a yield of up to 130,00 kWh/a, which should be around 50% of the apartments' requirements.

A central design and material element is located on the 12th floor: the 50 m² floor of the communal winter garden is made of rammed earth. The specially developed clay mixture was processed in the style of traditional terrazzo aesthetics and marks an innovative use of rammed earth in building construction. The floor is decoupled from the rest of the supporting structure for acoustic reasons.