OK I found the case I recalled.. Woodward vs God.
http://64.233.187.104/search?q=cache:z_QF_HVJMtgJ:ww5.cch.com.au/Tax%2BCases/aat0004.doc+woodward+rental+site:.au+pool+leisure&hl=en
In which the AAT decided:
40. In examining the function of the pool and spa, the Tribunal concludes that...