Claiming depreciation

part of this depends on the situation,  are you renovating prior to first rental?   in between leases? 

ATO has some downloadable PDF files which discuss this and provide tables to guide you on what categories of items are depreciated or claimed over what period

quote from ATO site

"

There are two categories of rental property expenses you can claim:

• expenses for which you can claim an immediate deduction in the income year you paid them, like council rates, repairs, insurance and loan interest, and
• expenses that are deductible over a number of years like borrowing costs, creating structural improvements and costs of depreciating assets.

You can’t claim costs associated with acquiring or disposing of a property, but they may form part of the cost base of the property for capital gains tax purposes.

Renovation costs and costs to repair damage, defects or deterioration upon purchasing a property cannot be claimed as an immediate deduction. These costs are capital expenditure and generally must be claimed as either decline in value deductions over the asset’s effective life, or as capital works deductions over 25 or 40 years.'

If you are trying to get the full picture (property+renovations) then you probably need a quantity surveyor the estimate the original cost and age of the base property and include current reno (assume real cost of that was tracked).

If you are just talking about your reno costs then you could do it yourself in Excel but would need to get the ATO doc to correctly categorise aspects of the reno for you capital works deduction……or just add it to the price of property to reduce CGT down the track when you sell (dont know how much we are talking about)