From The Who Location Guide:
"Keith Moon's house "Tara" began life at the hands of Peter Collinson, the film director responsible for Up The Junction and The Italian Job. Collinson owned the original property that graced the site, but having been refused planning permission to extend it, demolished it. In its place he built "Tara".
Named after his son, the house was was a strangely cuboidal and pyramidical construction, packed with all manner of futuristic labour-saving gadgetry.
Collinson put the house up for sale after deciding to emigrate to the USA. Moon purchased it from him in 1971 for £65,000."
And some pictures of Moon's Malibu Beach house here.