Most straw bale houses use the material just for the walls. Haus Hoinka by Atelier Kaiser Shen uses it for everything – floors, ceilings, roof – all wrapped in clay plaster and pressed into a spruce frame.
Like many of the small villages in Germany, the town of Pfaffenhofen carries the usual marks of its age: a church, half-timbered houses from the 16th and 17th centuries at its centre, vineyards rising picturesquely. Adding to a place like this means working within a grain already set – the form of the surrounding houses, the pitch of their roofs, and a familiar material palette of stone and wood. Haus Hoinka, by Stuttgart studio Atelier Kaiser Shen, takes the context as a starting point and then pushes it somewhere modern, yet tempered by ancient building techniques.
The brief came out of the client’s own work: a building made, as far as possible, from natural and renewable materials that can be returned to the earth they came from. The answer was straw. Bales of it, combined with clay plaster, form the thermal envelope for every part of the house – floors, ceilings, roofs and walls alike. The method dates to the late 19th century and has been having a resurgence as a low-fi building technique with plenty of positives. Straw is renewable, recyclable, and readily sourced close by, which makes it easier on both resources and climate than conventional insulation. It is also low-tech in the handling: the bales are pressed into a spruce framework to a thickness of 36.5 cm, with the excess simply trimmed off using hedge cutters.
The ambition was to realise all six faces of the house in this single construction. However, straw when used in a floor slab has to be kept permanently dry, and the usual answer is elaborate sealing. Atelier Kaiser Shen chose to raise the house a full storey instead, so the compact volume now rests on a concrete cross and four corner supports, lifted clear of the ground. The concrete earns its place by keeping the straw above it dry without needing a membrane.
With the timber shutters closed, the raised house reads as an elevated monolith above an open garden level, a composition of stone base and cantilevered timber that holds a direct conversation with the houses in the village. The simple form conceals a more complex arrangement: a nested semi-detached house of two units, each reached by a single flight of stairs from the garden level. Each apartment can then look in all four directions – east to the church square, west to the garden, north to the vineyards, south over the village roofs into the distance.
On the first floor the house splits lengthwise, on the second crosswise. Inside, the spruce structure and the loam are painted white in the unit facing the village and left untreated in the one facing the garden; outside, the silver fir board-and-batten cladding shifts plank width slightly between the two halves, a subtle hint of the arrangement within.
The raised ground floor leaves four open bays beneath the house, framed by the concrete cross and its supports. The client has already filled one with a granny flat; the others are left open to whatever the residents decide – an outdoor kitchen, a workshop, an e-car charging point, a summer living room, a winter garden in time. The approach, drawn from the Cité Verticale in Casablanca, hands part of the building’s use back to the people in it, on the understanding that the house will be shaped, and probably improved, over the years.
Materials were chosen for their ecological balance and their capacity to be separated and recycled. This means glued elements were avoided wherever possible, and every material, including its origin, is logged in a database for sustainable building products that the client developed. Haus Hoinka is a village house rethought from its materials up – raised, reversible, and left deliberately unfinished so its residents can keep building it.
