Having an unfair advantage I kept out of your 'Ring the Changes' competition for Häring's Garkau Farm (AJ 20.3.03) - but I can provide additional information.
John McKean's estimate of your photo being 'circa 1990' (AJ 27.3.03) is far too late. I attach a picture from the same angle taken in 1990 (above), which shows the effects of the restoration made in the early 1980s by Eberhard Zell.
Your picture is probably circa 1960, judging by the fact it has green paint and is less dilapidated than on my first visit in 1973.
The green paint was hated by Häring's assistant, Margot Aschenbrenner, as it recalled practices under the Blut und Boden policies of the Third Reich. Häring's original intention was to leave the wood natural, like the contrasting bricks and concrete. By the mid1930s when she visited it, it had weathered to a beautiful silver grey. The conservation architects stained the replacement wood brown, which is also wrong.
McKean was right to be puzzled by the columns dividing the window band, correctly present in your photo but due to alterations that were properly reversed in the restoration.
Readers will also notice the absence of the unfortunate infill to right of frame, which crashed into the pointed end of the root cellar. This, too, was removed in the restoration.
Peter Blundell Jones, Sheffield