Rammed Earth: Martin Rauch.

By Otto Kapfinger. Basel: Birkhauser. 2001. [epsilon]58

The benefits of building with earth are widely recognized by now, at least among the green fraternity. It is abundant and it is cheap; used locally (as it should be), it reduces transport costs, and an earth wall uses about two per cent of the energy needed for an equivalent wall of concrete; it is fire-proof, it is a good regulator of indoor climate (the oldest extant earth building in Europe, built in 1270, now houses a library for moisture-sensitive books) and it can be recycled easily. The downside is that its thermal insulation value is not particularly good, which needs compensating for by building thick, and earth walls must be protected from the wet, making them less viable for external use in Britain (but not impossible -- see Clough Williams-Ellis's classic work on Cob, Pise & Stabilized Earth, 1947).

This is a lovely book which extols the beauty and potential of rammed earth when moulded in the hands of an artist. Martin Rauch started as a ceramicist and sculptor, and later worked for a time as a development aid worker in Africa. Research work and an exhibition on Loam-Clay-Earth in the 1980s prefaced his involvement with buildings, and from 1990, he has been working with architects mostly in his native Austria but now increasingly further afield.

Although rammed earth walls are most easily built in long straight lines, they can be curvy and voluptuous, though I have yet to see curves in two dimensions. Always they are thick and monolithic, providing a visual contrast with lighter infill panels, and they have a striated ruggedness which appeals today in a way which probably didn't in the past, when earth walls tended to be hidden behind plaster and whitewash. Rauch experiments with the texture of the earth, often introducing patterns and clay tile string courses to help with weathering. Being so thick, the walls can incorporate heating pipes, and hypocausts feature in at least two of his projects. My favourite is a small chapel in Berlin (Reitermann and Sassenroth, Architects), on plan an oval inside another oval. The inner wall is made of earth mixed with coal dust and polished with wax emulsion, the outer one of vertical timber slats and glass.

Martin Rauch was not involved with the AtEIC building at the Centre for Alternative Technology at Machynlleth, mid-Wales, but those wanting to see rammed earth need not go as far as Austria to admire its Brutalist charm.