Granny flat and tax implications

Hi all, My mother and father in law have recently sold there house in Sydney's north and would like to stay in the area but have been priced out of the market and not many down sizeable houses available. (Unit is not an option)

We have a decent size block with a detached garage to be demolished with the thought of placing a granny flat for them.

I want to make sure we do this in the best interest for ourselves and the in laws.

I feel the best way is to talk to a tax accountant/financial adviser on this however they are not very willingly wanting to do so instead just talking to Centrelink.

They have no super and will have around 800k to play with after agent fees and paying off other debts

1. Does anyone have any tips on how to go about encouraging them a tax accountant/financial adviser is the way to go?

2. Can anyone recommend a financial adviser or tax accountant who knows the pension rules?

3. In building a granny flat are there any general rules one should follow when thinking about taking this option?

Thanks in advance!
Don't forget the lawyer. If they will be paying for the granny flat on your land there are many issues.

What if there is a dispute and they want to leave - who owns the house?

What happens if you die?

What happens if they die - do you inherit 'their' flat. What about other potential beneficiaries of their estate?

What if you became bankrupt?

Will you grant them a life interest? What are the tax consequences. Social security rules on gifting? = Special rules around granny flat interests.

How to avoid allegations of 'elder abuse', undue influence, unconscionability etc.

What if you want to move?

If you build and pay for it they could rent it, but what if they have too much cash and pension is reduced?

etc etc
I guess the main thing to do is to work out everything that could possibly go wrong and try to cover it with planning ahead. e.g. the parent getting independent legal advice can reduce or eliminate a claim of undue influence etc.