27. July 2026

Thermally Activated Earth-and-Timber Slab in the Lehm Ton Erde Office Building

The seminar room is spanned by an earth-and-timber slab in which water pipes for thermal component activation were rammed in © Lehm Ton Erde, Hanno Mackowitz

In the new office building at the Lehm Ton Erde workshop hall, a timber beam slab with an earth infill and additionally integrated thermal component activation was realised. The space serves as an office and at the same time as a hands-on development field for the interplay of timber structure, earth mass and thermal activation.

Construction and thermal component activation

The load-bearing timber beams span a distance of approx. 8 m and allow for an open floor plan. Between the beams, the rammed earth forms the thermally effective mass, into which a water-based system for cooling has been integrated.

The thermal component activation makes use of the heat storage capacity of the earth and reduces temperature peaks. Condensation that occurs can be absorbed by the earth and released back into the room air with a time delay. This moisture buffering additionally creates an evaporative cooling effect.

The space is used for team workshops and at the same time shows the many possible applications of 100% earth, entirely in the spirit of Lehm Ton Erde. © Lehm Ton Erde

Spatial effect and use

Even in the early phase of use, a balanced indoor climate is apparent, with a pleasant temperature, soft light and good acoustic properties. An integrated skylight brings daylight deep into the room and emphasises the materiality of the construction.

The earth-and-timber slabs meet the partly plastered rammed earth walls© Lehm Ton Erde

Added value of the Lehmit slab with thermal component activation in the Lehm Ton Erde office building:

Reduction of temperature peaks through thermal mass
Pleasant, balanced indoor climate
Improved room acoustics through mass and surface structure
Soft, natural light effect through materiality and skylight
Large spans combined with high building-physics quality
Direct insight gained from ongoing operation
Moisture buffering and additional evaporative cooling

Further development in operation

The office space is not only a functional extension but a further step in the development of the Lehmit slab. The findings from real operation feed directly into the optimisation and further development of the system.