Architecture: The house that Ludwig built: The simple truth about the philosopher Wittgenstein is revealed in the obsessive austerity of the home he designed in Vienna, says Peter Dormer

Ludwig Wittgenstein (1889- 1951), the philosopher, was a perfectionist in all things. From 1926-28 he helped to design a large, modern house on Kundmangasse, Vienna for his sister, Margaret Stonborough-Wittgenstein. Although the initial designs were by his architect friend Paul Engelmann, Wittgenstein gradually took over and completed the project with the same obsessiveness he displayed in Tractatus Logico-Philosophicus and Philosophical Investigations.

Interest in Wittgenstein has grown in recent years, largely because he epitomises the role of the tortured genius. To his careers as aero-engineer, war hero, primary schoolteacher, hospital porter and of course, philosopher, we can now add architect. A new and richly illustrated book by Paul Wijdeveld, Ludwig Wittgenstein, Architect (Thames and Hudson, pounds 45), examines the house that Ludwig built.

On the surface, the crisp, white house seems calm, ordered and logical. Looked at more closely, it is as manically obsessive as Wittgenstein's moral extremism. It eschews, for example, all forms of decoration. Wittgenstein abhorred ornament, a revulsion he shared with the hugely influential Viennese architect Adolf Loos.

Loos was very much a part of the Wittgenstein family's circle in Vienna and the philosopher was much influenced by the ascetic architect's famous essay Ornament und Verbrechen, in which he linked ornament with criminality. Wittgenstein's views on the same subject were uncompromising to the point of unkindness. He condemned the flower arrangements of the only woman he had anything like a mature relationship with. He also made her give up painting (he told her that she was not good enough) and persuaded her to get a humble job in order that she might think about the way she ought to live.

He was hard on himself, too. Indeed, the chance to design the house for his sister rescued him from a deep moral crisis following his failure as a schoolteacher (he was too strict with the pupils). But there is a contradiction. The house, although Cromwellian in its severity, was designed for privileged aristocratic living. It stood for excess and inequality, yet Wittgenstein found no difficulty in working on it. Wijdeveld says this was because the philosopher regarded the ability to live with wealth as a purely personal matter. He had given away his considerable fortune and lived extremely frugally.

Wittgenstein eliminated all forms of classical ornament from Engelmann's original design, reducing its architecture to undisturbed lines running parallel or perpendicular to one other. What mattered to him was unadorned symmetry and proportion, and the pure effect of light on architectural form. 'My ideal,' he wrote, 'is a certain coolness. A temple providing a setting for the passions without interfering in them.'

The philosopher revelled in the plainness of the house because it threw all the emphasis upon the proportions and upon measurement. His sister Hermine relates that 'Ludwig had such a sensitive feel for proportions that half a millimetre often mattered to him'. When he considered a newly installed ceiling a tad too high, he had it taken down and lowered by three centimetres.

It would be overstating matters to claim that the house Wittgenstein built for his sister is a great building; it is not. It is, however, rare for a philosopher to create something so physical and public as a house. And in such detail. Wittgenstein designed everything anew for the house, including window fastenings and door handles, one of which is still manufactured by the German FSB company. There are many people today who have never heard of Philosophical Investigations, but, because of the house he built, know Wittgenstein as a designer of door handles. He would have liked that.

(Photograph omitted)