Contact porter Davis, they will have all the original construction paperwork, if you have not, and would be able to tell you if the current structure could support a second storey, or whether extra structural support would be needed, in the foundations, and beams in the roof, to handle the load.

What additional space do you need? Is the alfresco under the roofline, could it be enclosed to provide you with the additional space you need? Keep in mind that when you build up you need stairs which means losing some existing space.

To expand on macyjeans comments -- how big is the section ? What is the house placement ? What are the views like at ground level , and 5 metres up ?

Going up is twice the work , so twice the cost -- at the very least , you are getting rid of 1/3rd of your roof trusses , reinforcing them , adding new trusses on the upper storey , and on it goes .

Unless designed as two storeys right from the start , I'm always reluctant to consider it .

Can you please tell us more?

I've seen plenty of added second floors around here. But there's a lot to it, as Pottsy talked about. From what I've seen it usually involves sacrificing a downstairs room, so a full-size family room becomes a staircase plus a meals area or a bedroom becomes a staircase plus a study nook, that sort of thing. Sometimes circular stairs are used which require less space and they can suit aesthetically but are less practical. You said you are not looking for a lot, just one or two rooms. One reduced or compromised room downstairs for the addition of one room upstairs needs consideration as to whether it's worth it.

It already looks like a fairly typical 4 bedroom. The laundry looks on the small side for the size of the house, but that's not likely to be going upstairs. Looking again, the alfresco appears to be under the roofline, so could be quite economical to enclose. What do you need the additional space for?

Thanks for the replies.

Bottom floor

Top floor master bedroom, en-suite. 3 bedrooms and bathroom.
We don’t want to give up our Alfresco area.
We’re on pretty good land location

Views look out onto an oval

We want a bigger lounge room that is more enclosed and bedrooms more separate from living areas as kids get older. Bigger laundry would be great too.
Thanks for the replies everyone. Thoughts?
We will call Porter davis Monday

Do you recall if you have a waffle slab or a raft slab? A waffle is quite common for cost reasons and will make a second story addition difficult.

Is there room at the front for a double carport, and then convert the garage?

You might as well look for a new home.

You are changing every room and location of plumbing, and then the costs to structurally put a second storey on the existing foundations.

It’s a waffle slab. Yeah ok Thankyou might be quite difficult.
No won’t be able to do that in the estate

Yeah ok thanks

Could you swap living room and bedroom 4 around.

A simple change to give you a separate living area and study space. I assume the walls are just timber studs, so they can be removed and rebuilt.

If the kids are studying that won’t be watching tv in the living area. The home is compact so multi purpose spaces would be beneficial.

Or this

Rhanks yeah like that. We have 3 kids tho so will prob need a separate bed room each

If you love the area and are set on extending up, an Engineer’s report will cost about $1500 and will tell you the feasibility on building an additional level. There are posters here that will give you rough plans so you can let the Engineer know what you have in mind. So have a look at your Council’s website for set back and over looking rules for second stories.

if the main restriction is the existing slab my suggestion would be to demolish the existing garage and it's portion of the old slab and build a new garage with suitable structure for upstairs kids accommodation and renovate the main house to improve floorplan for family activities.. but unable to read all the dimension you will need a builder and designer to survey the existing house to determine what's really possible

So you want to move the bedrooms upstairs and rearrange/expand the living spaces downstairs?

Your initial question indicated a change that was too little to justify the work involved and now it almost sounds the other way, too much to justify trying to do it to an existing house and perhaps better to look for a new home which suits those needs. Also it seems like your budget would need to cover renting?