Hi there, this is my wife's account and she has just showed me this post as she thought I might be able to help you. I am a local estate agent and have plenty of experience in half houses, I have recently advised a client in a similar situation as yourself who was contemplating the most efficient way to extend into a half house loft. With some suggestions a decision was made to create a master bedroom suite in the loft with an en-suite shower room. The staircase was taken from the larger of the two bedrooms so that there was two equal size rooms rather than one box room. The result was a very nice balanced space on all floors and my clients are very happy with the result. Although I am uncertain of the layout of your property and all half houses are slightly different from the next, im sure that a solution can be found for your own property. Feel free to follow this link to see the details of the house I am talking about, perhaps it might help to give you some ideas. http://www.pickwickestates.com/detail/2306/SE220HF_crebor-street.htm If you would like to discuss further I am happy to give you my details via my wife's account here.