renovations that are not repairs or maintenance are not tax deductible, "renovations" that improve the property only increase the capital base of the property.

Our housing bubble is only partially caused by investors, but is more caused by our interest rates being way too low - meaning that the cost of borrowing money is too cheap and accessible and inflates the value of all assets, be it property or any other investments. We have had record low interest rates (QE) for far too long and the RBA have been the biggest pussies not willing to correct the market. If you note from the GFC in 2008, our rates have declined to record lows in order to counteract this.