Hi Jasper
No worries. 30% holding costs is typically what the bank take into account as a proportion of your rental income the costs associated with holding the property (ie rates, water, property management, repairs etc).
So in your case, with Rental Income per week being $260, then you will probably have around $78 per week of costs associated with the property ($260 * 30%). On top of this assuming your interest is 7.07% and you borrowed 100% of your building costs of $216,000, then this will equate to $293 per week of interest only costs. On top of this because you built the property you will be entitled to depreciation. An estimate of this is your building cost $216,000 * 2.5% which equates to $103 per week and Furniture & Fittings of $3000 per year equates to $57, therefore total Non Cash deductions per week would be $161.
Therefore, your cashflow per week for this property will look something like the following:
Rental Income $260
Less Property Costs of $(78)
Less Interest Costs of $(293)
Net Income before tax $(111)
Less Non Cash Deductions of $(161)
Net Income after Non Cash deductions = $(273)
Plus Tax Savings Assume you are in the 30% tax bracket ($273 * 30%) = $82
Net Income After Tax Savings = $(191) per week
Or $(9945) per annum
In terms of your equity, if the property is now worth $360,000 on a bank valuation then you can refinance the loan to 80% of this value. Which means if your loan is currently $216,000 then you can refinance to 80% ($360,000 * 80%), so your new loan is $288,000 freeing up $72,000 of equity for your next purchase. If you borrowed 100% of the building costs, then your return on investment is going to equal whatever your total interest costs have been while being built + your cost of holding as calculated above.
Hope this helps with your analysis.
Best Wishes
Corsa