Potential development gold coast

I have a few questions that I am hoping someone might be able to help with.

Firstly, and most importantly (because it may determine whether the subsequent questions are even worth asking!) - can anyone tell me how to determine development potential of a block in Palm Beach, Gold Coast? More specifically, a family member is on a 700sqm block and is looking at moving. I love the idea of purchasing the house, but need to determine whether it's worthwhile or not (i.e. what exactly the value-adding potential is - duplex? subdividable? or just big reno)

Secondly, and this might be more appropriate for the property finance category - I need some suggestions on how we could make it happen and if it's even possible.

This is our present situation:
Own a house in Brisbane - bought for 435k, did 50k reno (husband did most of the work), refinanced earlier this year to purchase first IP and was valued at 550k. Since then we have put another 15k into deck/roof/fence and landscaping.
Purchased first IP near Redcliffe (north brissie) in October. Paid 450k for it, put 15k in, very good rental yield for the area (5.4%).
FINANCE: Currently have 440k on PPOR (130k used to finance deposit/costs for IP) and 360k on IP.
We borrowed at 80%, so understand our options may be limited...

I am wondering if anyone has suggestions on how whether there's any way we could finance purchase of the relative's house without selling our PPOR/IP (even creative ideas like vendor finance?) or whether we bite the bullet and sell the Bris house (we've made good capital gains, considering we did a lot of the reno ourselves, but I'm sure there's many more to come) and hope that developing the block on the Gold Coast will give us even more gains?

We are more than prepared to live in the house as is for a while, until we can get things going and we also have the option of living with my parents for 6-12 months if absolutely necessary to save some money.

Thoughts? Do you need any more info? Any advice welcome.

the first thing I would do is go in and talk to council and just ask them. Keep it simple. They will tell you straight away what could be done and whats impossible due to zoning etc. This will save u a lot of time.

could you give me the street name of the house?

Had a very quick look at the street and I don't think u can subdivide, duplex etc (i didn't read the council website or do any research) just my very quick glance so i could easily be wrong. But i don't think i am.

With regard to reno.. depends the price it was bought for and what the price differential for a new build in the area. eg if you paid 150k for house and now brand new 4 bed builds in the street are selling for 800k plus then it might be worth it. I would make a 5 minute phone call to council to check re site dwelling type permissibility. Alternatively you can search council website. the answer is somewhere in there.