Your designer should be able to suggest some ideas, but a lot will depend on your budget, and the slope of the land. If the rear of the house is very elevated to make the most of the views, you would be better off with lightweight construction that can be maintained easily from your balconies, rather than masonry construction, which can get expensive if you are a long way above the natural ground level. So you need to consider your budget, the height of the building, the surrounding environment (urban or rural), how it looks from the river, the orientation, your climate, and how close the new building is above the flood level. Best of luck with your considerations, Regards Dr Retro of Dr Retro House Calls.

Amazing to see this brought to life! fantastic project!

The issue is not so much the cladding material, but rather the articulation of the extended building form. This could be a simultaneously exciting, interesting and sympathetic extension utilising shingle cladding that wouldn't necessarily reference Hampton's. If there's anything too Hamptons going on here it's the small proportioned windows with the external shutters that give it a bit of a "dollhouse"popped on the top look. You've got a stunning beautiful home frontage, but the extension form is kind of sticking out/up the back and the fenestration looks out of balance by being perfectly symmetrical. Federation architecture is not symmetrical like the Victorian era predecessors, rather it is an asymmetric compositional balance that in your case should be recognised and countered appropriately with the design of the extension. When selecting appropriate extended cladding material it should be working towards texturally balancing the building and being complimentary overall. Professional recommendation you revisit the articulation of the upper extension, at the very least loosening up the fenestration with more glazing and potentially a more complex roof form with a smaller projecting gable (offset) as a reference to the frontage. The cladding choice becomes less critical, and shingle texture that ties in the roofing texture could work well. Weatherboard is bringing something new in, and if you go flush panel without a more contemporary design and articulation it will look wrong Good luck PD :) www.pauldistefanodesign.com

I'll be the toned down person . The 'outside' is brilliant -- the corten , the angles , the wooden poles , it adds to everything ! Even the kitchen is a step above a lot -- it has style and texture and a variety of colours and materials , and I love the wooden light and breakfast bar 'cap' and table . Then there is the pool shots , and that side of the house looks like a school building . You can call it trendy or industrial or whatever you like , but seriously , you couldn't have spent $50k more and added a variety of materials and tones and 2 or 3 'juts' in the walls ? Okay , I am probably weird , and own some commercial buildings , and I go out of my way to add some style and character to them , using all the tricks you've used on the other side -- even commercial buildings shouldn't be square concrete boxes IMO , and yet you do exactly that to a high end house ? Each to their own , but I'd have more 'fun' on that side if that was me .