Hi Allison, our block (and many others) has the same aspect with the rear facing west. When designing our new house we had the option of building the open plan along the south side of the block with the alfresco facing the north, or along the back of the house with the alfresco facing west. We chose the latter facing west for two reasons, firstly because we're one down from a corner block our north boundary is the rear boundary of two neighbours so facing north meant looking into their backyard, and secondly because our block is at the higher point of sloping land we have nice sunset views over treetops and rooftops. I should mention the backyard neighbour's house is only a few years old so we're not likely to get built out anytime soon, but something you should keep in mind if the house at the back of yours is really old chances are a new one could pop up in the next few years and you don't want to be staring at a two storey house. A few other things to consider... all walls of the extension should be properly insulated, all windows and doors should be double glazed and the deck should definitely be undercover to minimise direct sun into the house (see photo). Below's our open plan and a photo of the alfresco which was taken around 5.30pm where you can see the house only just starting to get direct sun late in the day. Otherwise, I think your best alternate is to extend along the south side of your block with a deck facing north, it's generally the better orientation, just wasn't an option for us. Good luck! :)

I personally think that it is overkill to get an architect because you think that the orientation of your home is difficult. Its not. You could be wasting money getting advice that is not required. My own home has the heart of the house - the kitchen, facing north. This is ideal because we spend a lot of time here and it is great in winter with slow cooked food in the oven, using the oven to warm the room while also getting any winter sun that is available. My best advice to anyone is to have a home with doors in it; open plan is fine for people with money who can pay for double/triple glazed windows, insulated walls etc and elaborate air conditioning systems. Most people need to think about how they can get the best out of the money that they have available and being able to close doors to keep rooms cool or warm is to me, essential to the fuel economy of the home. So your orientation to me is what is often recommended - it certainly isn't east west. Just use trees correctly to help insulate your home even further.

Orientation plays a huge part in the comfort of a home, & it's energy efficiency. In simple terms, a northern aspect is good, increasing light, sunshine in winter, shaded in summer (by appropriate length eaves). A western aspect is bad (especially for bedrooms), as the sun is low in the sky in this direction & difficult to shade, at the hottest time of the day. You have a SW frontage, & a NE aspect. A NE is a very good aspect, so you should take advantage of it! Currently only the master bedroom faces this direction. It would be much better if you're living areas faced this way. Instead they mostly face NW (along with a couple of your bedrooms), which will result in a very hot home on summer afternoons. So unless you have privacy issues with neighbours, views to take advantage of, or other issues, which have lead to this design, I'd be looking at a redesign. Aiming for living areas to face NE, the majority of bedrooms SE, with the garage on the western side to protect the home from the hot afternoon sun. So, if you like the overall layout of the plan, try to achieve the above without too many major changes. Flip the front part of the house, so the garage is on the west, & the minor bedrooms face SE. Rotate the living areas 90°, & use the width of the block, so that the master doesn't take all the NE sun from the living areas. Flip the master, so that it has NE & SE aspects, & the ensuite bares the brunt of the NW sun. Or switch the master with the living areas, so they have an even better NE aspect. Though you'll need a longer hallway to reach the living areas from the entrance of the home in this case. Read more about orientation & passive solar design on the brilliant Your Home government website, https://www.yourhome.gov.au/passive-design/orientation

Consider whether you need task lighting on the island bench. If you are using pendants they only have a limited space to be installed and only room for two- does this work for how you want to use the bench eg for food prep? The skylight will be a real feature during the day but not so much during the night. Another idea might be lights or pendants over the island and the skylight in the space between the dining and kitchen.