Agree with Stewie, western bedrooms are not a good idea.
If possible I'd be trying to flip the rear of the plan, so that all the bedrooms are on the east,…

Which direction does the house face, ie. where is north in the image?
Orientation is absolutely critical when it comes to energy efficiency & comfort.
https://www.yourhome.gov.au/passive-design/orientation

Jeez I hate lots of volume builders. You do your best to learn about energy efficient building design (like passive solar design) - because many builders still don't seem to…

Looking good. Lots of northern glazing in living areas, little western or eastern glazing. Perfect.
But, along with the northern glazing, you actually need that northern sunlight to make its way…

Try to find a plan that has you living areas facing north. They'll be brighter, & warmer in winter, heated by the northern sun.
Try to limit western windows (this is…

With the current plan the alfresco will totally shade the living areas. You'll get zero winter sunshine through your living area windows (foregoing that free heat), & these rooms will…

You've been blessed with a block with a north facing backyard.
This block orientation is more desirable & more expensive than other orientations for one reason, & one reason only.
This orientation…

For that sort of money I'd be aiming higher than 7 star. 6 stars in the minimum allowable for Australia's very poor standards. Plus houses rarely actually achieve the rating…

Steel has high thermal conductivity, so heat can flow through the frame, bypassing insulation. This is called thermal bridging, which can be a problem. Thermal bridging is not as big…

My main concern would already be, is the house orientated correctly? That is, do the living areas face north?
A home with north facing living areas will be more energy efficient…

Agree, you really must have your living areas facing north. The home will be more comfortable, lighter & your bills for heating & cooling will be lower.
Orientating a home in…

There is a common floorplan thread somewhere on here. If you can find it & revive it that would be good.

It's a catch 22 situation.
The block orientation means you won't have many northern windows, & you'll have lots of eastern & western windows. These windows are difficult to shade, so…

Same problems, the covered alfresco shades much of your living areas. Meaning they'll be dark, & cold in winter.
A couple of solutions. Either get rid of the roof above the…

Unless you're in the tropics, your south facing living areas will need heating in winter. So I'd be adding a doorway between the kitchen & the hallway, so you can…

Orientation, orientation, orientation!
Get this right, & your home will be lighter, more comfortable & more energy efficient.
Living areas to the north. Bedrooms to the south & east. Rarely used rooms…

I'm not an expert in the field, but I'd always be wary of buying off the plan.
Particularly in the middle of a global pandemic. Real estate prices may have some…

Agree that extending out will simplify the roofline, a good thing for solar.
angi.f, are you the sort of household that would use a mudroom? That could be a good use…

Subdivision. Yes, it's possible in some areas. In other areas, no it's not. So you'd have to ask your council. But usually the block would have to be a fair…

Er, a steel frame for it's passive design advantages?
I think you've got that wrong. Steel, like all metals, has high thermal conductivity. This conduction of heat creates the issue of…

Dupe, due to poor editing

A have a bit more time to write now, so will start of by asking a few questions.
Where are you located? The climate in Hobart is very different to Cairns,…

This brilliant government website will teach you everything you need to know,
https://www.yourhome.gov.au/passive-design/orientation

I wouldn't be leaving solar PV for too long, as it's such a good investment. It should pay itself off in about 3 years, then will save you $1.5k+ depending…

Where is north on the image?
Orientation has a huge effect on the comfort & energy efficiency of a home.
https://www.yourhome.gov.au/passive-design/orientation

Which direction does the block face? Is it an average size? What are the neighbouring blocks like.
My number one pointer would be to choose a block that faces the right…

Can you draw your proposed plan? I'm a little lost about how much room there is. Doesn't help that I'm using a tiny phone, which won't let me zoom in…

Sorry, I meant "an attached granny flat may be a better option".
I don't want to edit my above post, as the formatting will go crazy. A problem with the Homeone…

It's nice that the easement is to the north. Build as close as you can to the southern boundary, creating a northern yard. Flip much of the plan you've shown,…

Orientation is critical, & plays a huge part in the comfort & energy efficiency of a home.
https://www.yourhome.gov.au/passive-design/orientation
So where's north on the plan?
If it's at the top…