Thanks for getting back so quick! Yes we have discussed just renting it out for now & renting a bigger place for ourselves. I think this will be only option. Thanks again Jodie

assuming you could get planning approval for a suitable extension by the time you add on two bedrooms and a bathroom (within the 8.5m x 5.2m = 45sqm) at $2000-$3000 per sqm i wonder if you would get a reasonable return that would justify the extra costs for your mortgage and loss of outdoor areas... what is the sale potential for the bigger duplex and how long would it take to sell? ...calculating cost of the extra interest on your mortgage against cost of renting elsewhere minus rental return on your home after expenses for a few years and maybe, by the time the few years have elapsed, the kids could have left home and you may find that you would need to downsize!! but, subject to approval a smaller extension might give some extra breathing space without overcapitalising ...my suggestion is a simple 25sqm hip roofed extension with master bedroom suite and a better kitchen with study nook and pantry and also consider enclosing the carport to use as an occasional rumpus room for the kids

Dr Retro has nailed it I think. There will be very little chance of obtaining approval to permanently increase the floor area in your context for all the reasons he stated.

One left field option might be a "tiny house" relocatable building? Because these can be defined as temporary structures that may provide some wriggle room with Planning and Body Corporate constraints. I think it is a long shot but may be worth checking, first with the Body Corporate (or equivalent) and if they are amenable, then the Council.

You will likely be time-bound on the duration of the temporary building and will need to remove it when you eventually sell, but it could be an alternative to "dead money" rental expenses and provide a bridge to tide you over until the market rebounds.

Thankyou Oklouise and for taking the time to do a floorplan! I really like the idea of the master pushing out.

We are weighing up the option of renting as opposed adding on to the mortgage. The rent we would get wouldn't fully cover the mortgage repayments either so we would be in the same boat really with the cost to rent and the cost to invest into the house. And then do we just sell and just start again?! So much to think about! Thanks so much for your time : )

Thanks for your input John. We don't have a body corporate as the land and house is our own and we have had the strata done . It is two houses attached to each other by a wall only and we don't share rates etc. The block itself is on a corner so hopefully the council may offer some concession? Our land is 488m2 so not so small that I think the council would let us build further on it. We just can't go any further north on the block. Thanks for your time : )

only way to make an informed decision is to have all the facts so why do you need/want 4 bedrooms? how would you access the extension from the original, what would you do with the kitchen, would you prefer to enter the house on the north or west with closer connection to the carport....real estate agents should be able to clarify most popular sale and rental properties.. how many bedrooms, baths etc so you can develop a better idea of most cost effective options.. ask council for an opinion before spending any money..i've always found councils quite easy to deal with provided you have enough supporting information and realise that you'll eventually have to make a formal application for a formal answer but if the block is 488 sqm and the existing house and carport about 112sqm you could add another 50sqm and only use about one third of the block ..what do your neighbours think are there likely to be any objections,

OKlouise's idea is good, & as suggested, even conservatively it's a minimum $120K, but more realistically a $150K-$200K odd exercise (as it involves moving the kitchen and mucking around with rooflines etc) in a contracted situation, factoring in any permits and fees, design & doc etc, so does it stack up with affordability and/or value add?? Going up to consider a 2nd storey it will be at least double that and some. You'd need to discuss with a real estate agent as well in order to work through what your best option is here. The thing is renting ultimately puts money in someone else's pocket, but it does avoid the hassle of a project, but is the best long term? Refinancing options can work well, particularly if you can swing a line of credit scenario that is based on a high value add proposal that potentially be overshot to embeds the cost involved with the borrowing over a period of time within the amount borrowed...so essentially the investment and property value capital gain over time works together to wash it's own face so to speak without you having to find more coin.

Good luck! PD