Hi Violet, How exciting new projects are always stressful but soooo rewarding in the end! A cluster of pendants sounds brilliant :) they are certainly on trend at the moment and give clients the ability to put a cluster together they love! Also helps when you're a bit indecisive. You can certainly fit a cluster in this space, the drama is in the staggered ceiling heights, not just the width and spacing of the pendants themselves. These are some options on how you can space your pendants, there are no strict rules or dimension requirements when designing and placing your pendants. You are free to explore your creativity with this! So do not take the above as mandatory just a general idea. Some options you can do are: https://www.golights.com.au/sandra-lidner-selene-pendant-light-in-clear https://www.golights.com.au/pendant-light-tom-dixon-etch-shade-e27-32cm https://www.golights.com.au/foscarini-urquiola-and-gerotto-caboche-pendant-light-in-clear https://www.golights.com.au/pendant-light-tom-dixon-etch-shade-e27-47cm  https://www.golights.com.au/pendant-light-stainless-steel-tom-dixon-etch-web-e27-65cm You can also do a range of pendants from the same family, but in different shapes for example the George Nelson Bubble Series: https://www.golights.com.au/george-nelson-bubble-lamp-ball-pendant-light-white-50cm-criss-cross https://www.golights.com.au/george-nelson-bubble-lamp-apple-50cm Of course the design depends on what is filling that void for example the shape and path of your staircase! Once you have some drawings or a photo feel free to send them over if you still need some more help! Good Luck with your build and search for the perfect pendants! You can always call us on 1300 798 220 for more help!

Those holes in the concrete are from the concrete pour. These are not tilt panels as tilt panels are cast lying flat and do not have the holes apart from 1 or 2 from lifting. This concrete is insitu cast. The walls would be formed up with form ply, lvl formwork and the ties. The holes you are talking about are from the formwork ties. As concrete, when wet, is extremly heavy and fluid. The concrete is constantly trying to escape the formwork and get to the ground. The avoid formwork blow outs from the pressure, they use tie rods between the form walls. These rods go through conduit pipes which are in between the formwork. They use the conduit so the tie rods are not encased in concrete making them a permanent fixture. Once the concrete is cured, and the formwork is removed. The tie rods can then be taken out leaving only the conduit. These are then tapped out leaving you with those holes you talk about. If you wish to replicate the look, it will require an engineer, plans and permits and an experienced formworker and concretor. I will attach a photo for further understanding. Scott.

You could add a chaise lounge or a comfy chair and table for a reading nook or an office area if you need one, a computer area but whatever you do don't over clutter it keep it sleek and sexy and or a comfy chair as suggested with a little side table for reading, I also like the idea of a place to put coats, shoes etc if you must enclose it. Maybe even a small wine bar? with a couple of stools. I decided to google is and will give you a link to many pics to give you more choices. https://www.google.com.au/search?q=pics+of+what+to+do+with+space+behind+floating+stairs&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjFy-n9p4vZAhUEF5QKHSvhAOMQ7AkISg&biw=1280&bih=893

it looks like one of those supersized American Mcmansions which is fine if you measure the value of a house by its size rather than the quality of its design and the relationship to its site and the environment. You must have engaged your architect with the knowledge on the style of work he does? I would strongly suggest you research American architect Sarah Susanka and her work with "The not so big house" before you have a meeting with your architect. A well designed home is a lot more than a shopping list of rooms. Even though I don't like your design I do know that some of my clients have trouble visualising a plan and sometimes they don't like what they can't understand. I would arrange a meeting with your architect so he could explain why he has deviated from your brief. There may be some very good reasons, such as capturing views, or getting the winter sun, but it is hard to suggest without knowing about your location. By the way do you realize that your posting has appeared on the Australian Houzz forum? Best of luck, Dr Retro of Dr Retro House Calls