Maybe if you got a plain white opaque blind you could then use that as a projector screen? Someone here may be able to say if this would work or if you need a specific type of fabric..

wow I love all these suggestions. I was going to suggest a grasscloth wallpaper, because it has wonderful texture. But I'm quite taken with the shelves idea now.

Thanks Lockmac, looks like you have master and en-suite before living room so prob a good 5 metres of hall or more at 1.8 wide before you meet living room. That is a great greeting space. You can then narrow to 1.5 outside living room. The 300 mm would be better used in that room than hall, the walls u circled for me. You should also add doors, perhaps large glass sliding door, to the living room as I note it has a tv and sound travels. My biggest regret is not having a door on my living room of the family/kitchen due to noise issue and sadly can’t add one due to several constraints. Thankfully I did add doors to hallway leading to bedrooms both for privacy and noise control.

how long do you want to live in the house? could an external extension to create an alfresco or a separate small room be useful or can you rearrange internal spaces?...the structural costs for an extension are in removing an outside wall and changing the roof, floor and ceiling to create one bigger room and an extension would also reduce what i expect is a very small outdoor area??.... ...we've spent hundreds of thousands for one extension that only increased floor area by 6sqm but that required the whole roof, the walls and floors to be lifted and replaced but we are very happy with the results despite the cost...post a floor plan to invite ideas that might clarify options and keep in mind that renovating a kitchen and bathroom could also add another $50,000 or more without extending the building