I would loose the doors to the side- you won't enjoy the best view, don't need the light but could do with the wall space. I also think the double sided fireplace is a choice for you not future buyers as it limits the wall space and use of the side room (which is fine). Personally I don't think you gain much by making it a dining room next to your current dining space. But I do think reclaiming an underused room and it having lots of possible uses is a brilliant plan. I think when you get the builders in you should either put a porch on the side (and make it big enough to also be a laundry room). Alternatively make the whole room longer by extending a few feet into the back garden so that there is room for both a shower room and a laundry and then move the side door to the back giving more privacy to the bonus room at the front.

Thanks Kitchen Republic! We did a couple of like that in our days of house building, but the support had to be under the join. However i'm sure the engineer knew what he was doing when he did the calcs! I wasn't confused over the pipe, i think that was Tanya. Still think it would have been great to have two sets of doors with one supporting column so that you can open out and see the whole garden, then continue the floor height outside for that inside / outside feel. Or, have had the plan the other way around, so that the bi-folds were on the 'living' side and the window in the kitchen, for a view straight through on the living side front to back. However, the window position where it is offers a great little corner for a seating area as per the Kitchen planner's picture. In answer to the original question:- Firstly check with Building Control, the window is in a kitchen and may have to open to be certified., or check with FENSA, ( or your glazing company, as they should know ). Secondly, have a 'pivot' window. This then does open, but is the single, unobstructed pane of glass that you would like!

Hi @Ollie Chambers ah we still haven’t started the work! Mainly delays due to our indecision! We’re starting February now and have decided to go with the kitchen in the ‘middle room’ and the living area in the 3m x 4.5m extension with sliding doors across. The main issue is still the extraction- it’s not a huge space so hob not too far from doors and as having sliding we can open just slightly and have opening roof windows in extension. We’re also having a ducted extractor fitted which will go through the utility (through ceiling) to outside. This can be ducted for 5metres (reducing by 1.2 for every turn) would be too far for you as yours is larger than ours? It’s going to cost quite a lot and we’re still exploring this as I’m not convinced it’s worth the cost as I guess the further the distance to the opening the more reduced the extraction. We cook a lot so we need a system that works. It’s not perfect I’d much prefer to have a window/outside wall for extraction but we have considered every other option and this one suits us best. I think it will be a case of the doors being regularly opened! I don’t have any floor plans etc but am happy to send you some and update you when the work is complete.

Hi Keiblem, I've only started to look into the japanese baths as well. I came across the following https://www.omnitub.co.uk/  http://www.bathroomexpress.co.uk/acatalog/pegasus-deep-soaking-japanese-bathtubs-whirlpool-baths.html http://www.bathroomexpress.co.uk/acatalog/pegasus-oronsay-whirlpool-bath-deep-soaking-915x740.html http://www.bathroomexpress.co.uk/acatalog/pegasus-islay-whirlpool-bath-deep-soaking-1370x740.html I also found this pdf which i have yet to read: https://www.cabuchon.com/wp-content/uploads/Guide-to-Choosing-a-Deep-Soaking-Tub.pdf  They are still lighter than cast iron tubs and the amount of water they can carry is normally around the same as a standard 1700 tub or less depending of the size.