I really like the storage ideas, suggested here; as we ha d a small flat, which had a built-in storage area under the stairs. Looked good and was very useful and practical. If you don't need a storage, I can imagine a cosy reading corner; a comfy sofa, where you can either sit or lie down, scatter cushions...if enough space, you can put a bookshelf behind the sofa. As a powerpoint already there, you can stand a nice-looking, practical lamp; for reading or to create a pleasant atmosphere :) Good luck!

I too own a Qlder and found it difficult to choose exterior colours. But I do think you need to keep the handrails the same as the other handrails - blue. The balustrading needs to be the same as the other - beige. I think if you want to put the red somewhere, put that on the actual steps and decking on the door level.

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

yes oklouise, I hear all that - absolutely yes it's all about clients understanding/working out properly what they need.........and it's great to be able to seek comments/thoughts on Houzz from a broad range of backgrounds/experiences......the issue though is when it gets into territory where (from my perspective) clearly experience and professional skill will help resolve the problem most effectively (such as on this particular one) that it's therefore appropriate to suggest this the advised way to go.......I suppose I see frequently here capacity for designers to be able to "cut to the chase" most effectively, but of course this needs to be done in a manner underpinned by a thorough understanding and establishment of what the client needs in context, and yes very often the client will require more time to work this all through.........I however still see our role as relevant in that part of the process though, and not necessarily having to "wait" for that to happen, because ultimately as professionals in this position (i believe) have a responsibility (as part of our role as a consultant) to educate people appropriately and thoroughly so they can develop the skills to be able to consolidate their decision-making most appropriately for themselves and the project - by the end of the journey, I find my clients are rather quite the experts!..........this however involves a collaborative approach, egos are shelved and an intimate working relationship, which is very different from the approach (that some designers work to) which is essentially selling a "product" or particular end result, rather than a service....significant difference, and again, horses for courses ;)