Clau2000 our manufacturer was in Melbourne, supplier in Canberra. Despite being happy with the product we really struggled with the level of service from the supplier. Quite frankly the business owner was rude, uncommunicative and very difficult to deal with and I would hesitate to recommend her business to anyone. At one point we contacted the manufacturer but he insisted we had to go through his ACT supplier and could not order directly from him (either us or our builder). Our first set of windows were installed on a westerly facing wall & get direct sunlight for the hottest part of the summer afternoon, they have been installed for 4 years and are showing no sign of deterioration. We went with E10 glass, double glazed and they do an amazing job of blocking the summer heat.

A couple of 'warnings' too -- firstly , have you signed a contract ? As Dreamer says , they have a certain buying power , but also there is a 'margin' there too . Retail value may be $20k , they may buy for $16 and charge you $20k . You probably won't get the items for $16 , so lets say you negotiate them down to $18k . You will get some resentment and lack of co-operation from the builder , but also their labour price isn't going to be as sharp either -- if they think it might take 1000 hours at $80 , they'll now quote on 1100 hours , as there's no 'margin' . But even worse -- what if you buy something that doesn't fit , doesn't work , isn't quite right , turns out to be poor quality . Get a window measurement wrong by 10cm , and you'll be stuffed . But if the builder organises everything , its all on him/her . It's almost like turning up at a restaurant with your own uncooked steak and veges , and wanting to just pay the chef for their time cooking it all . . . . . . . . then blaming them if the spuds taste a bit off .

"north-facing block (the front of the house faces north)" "The aim is to make the most of natural light" Did you choose the block for that reason as it was promoted as a desirable 'north-facing' block? A corner block with north to the long side facing the street instead of the limited front is what maximises the light. Your plan only gets the benefits of it to the living room and the garage. On the plus side, having neighbours to the west gives some protection from the unwanted afternoon sun in summer. It's useful to have a washbasin in the wc, if you can adjust the neighbouring WIR to allow for adding that. I noticed too that the neighbouring hallway in one version looks unnecessarily large but I'm not sure what's happening with the different versions.

the two plans are close to the same size different arrangemts make some room bigger in each plan but what does your builder say?? plan 2 has a bigger alfresco, bedrooms and office with smaller family and dining area... best choice depends on your priorities eg do you want to regularly entertain big crowds, what sort of WFH space do you need...can your WFH be achieved with a computer, desk and a bookshelf or do you also need space to meet clients and storage for sales equipment and supplies , what do you need for your prayer space, how much linen and bedroom storage do you want eg plan 1 has 2m of biw for beds 3 and 4 while plan 2 has 3m of biw for beds 2, 3 and 4, do you also need space for a computer nook, coffee machine, exercize equipment or hobbies with speciliased equipment like sewing machine and gardening tools??