Make the most of the era and the exposed bricks. Put in a large skylight and fit wall garden system to "green up" those bricks and larger pots on the base. The brick base is perfect to hide the drainage system you'll need. Get a steel fabricator to weld up a drip tray to fit inside. Mesh over the top covered in your choice of pebbles or a sheet of CoreTen rusty steel laser cut to a design of your choice. Some Balinese statues maybe. Year round herbs.

I have used Saatchi Art (saatchiart.com) to both browse and purchase art for our home. Original art work can be purchased and most artists have prints at a more affordable price. It's a good place to determine what styles and mediums you love as you can filter your search. For Australian art I love Blue Thumb (bluethumb.com.au). All Aussie and all original. Very few options for cost effective prints unfortunately. I'd be cautious about filling the space for an instant look. As everyone before me has said "art is personal" and as such, I think it should grow with you and your space. Start with one piece that you really love, big or small and work around that. I have found that putting unusual unexpected items on the wall makes for interesting 'art'. My husband's baby shoes (circa 1953) and now our children's first shoes are objects that always create conversation when guests come over. I have a Mexican art cross (we're not religious, the colours and the metal work drew me to it), a vintage wooden Indian spindle, African birds in a tree hand-beaten and cut from a steel drum, a clay mask my daughter made in art class, a woven Maori kit bag, some art that our kids have done at school (put into Ikea frames so they are always the right size. We change them as something else we love comes home), a hand-made ceramic tile, a growing collection of geckos found in antique stores, vintage travel posters in frames, (I'll stop listing what we have!)...all these items and more, have been collected over the last 20 years and put up around our collection of art or in clusters to create stories. I've collected the initials of our family (yes the child with the "K" is not thrilled it's so small and the child with the "G" feels he's by far the favourite! Needless to say both will be replaced in the future when a more appropriate size comes to light) from vintage stores both here and overseas. Our walls are a growing collection of art and objects and at any time I can move things around and change the composition as a new item is discovered. Best advice I can give you is to have fun with it, enjoy creating your own gallery, it's for you to love you're not required to impress anyone else.

Refer to your fridge specs before you close anything in. Fair Trading laws in this country have obsoleted warranties. There is now a sliding scale of reasonable expectation on consumer items which means manufacturers will rely on their tech specs more than ever. Check what minimum clearance your fridge officially needs on the sides and above the machine for ventilation before doing anything. Get your lighting working for you. Choose a 'warm white' lamp - not daylight or cool white. Cool whites kill off the warmer hues and makes things appear cold. Change, add or move your lighting to have two small gimbled ceiling lights wash down the face of the joinery instead of one bright light focussed on the fridge. Lighting can make a poor space look great or a great space look poor.

My advice is to think about the working/function as you need it for your family. Prioritise that (as a starting point) and get that happening somewhat free of a "box" shape extension and see how that all sits - it's like you're trying to squeeze it all in to a specific shape and then struggling with certain details....you're suggesting/entertaining ideas like a functional laundry/bag drop zone etc which 100% is important/relevant for a busy family of 4. The problem seems that there hasn't been true clarity on the function/requirements before the design has been proposed. Is it too small? Well it depends on how exactly you intend on using it - how many people need to be able to sit at the table or on the lounge etc..this will dictate scaling - whether or not you'd like a butlers pantry or not. Is the 3rd toilet needed? Well ultimately nobody can tell you that one way or the other - you will know whether functionally that is a requirement necessary for your family - all these are questions you will have (or need to establish) an opinion/position on one way or another and then (should) be able to work through (more effectively) & resolve with the architect whom you've engaged.....you are obviously staging the project which can be logical/necessary, and given this there may in fact be alternative and arguably more cost effective design options available for you (such as a 2nd stage "clean" extension for a master suite), but realistically that involves greater understanding/information of the site/context and your particular budget in order to provide specific advice/suggestions as to how best to achieve your goals...Good luck :) PD