Outdoor Pool Lachen, Thun

The heart of the entire Lachen sports complex in Thun is the lido with a view of the Alps. Both the pool facilities and the main wing, a listed building dating from 1932/33, have been completely renovated.

The task was also to question and define the edges and transitions to the rest of the campus and the lakeside.

A new winter use (during the day) is the integrated riverside path and the possibility of temporary gastronomic use.

The cloakrooms in the main wing (listed building) were rebuilt and installed, the technical wing was extended and all pool facilities (50m, 25m, non-swimmers) were enlarged and renovated. In addition, the pool water systems were renovated or replaced and a photovoltaic system was installed.

After the refurbishment, the lido will technically comply with the latest regulations regarding pool water systems and energy efficiency. The extensions and additions to the pool facilities create additional water areas for free use and for schools and clubs during the summer months.


Stadt Thun. Amt für Stadtliegenschaften
CH-3602 Thun


Trachsel Zeltner Architekten AG
CH-3600 Thun



Nature of the building project


Type of building

Outdoor pool

Our services

  • Planners’ association for the technical planning of the building services (heating, ventilation, plumbing, pool water system and stainless steel pools) including technical coordination for the entire building services
  • Energy Concept





Pool water system

Stainless steel basin