A sliding door is just a big window, and if correctly built in (check if the glass is the correct sized for the door if a bit old) with the correct sized lintels this should not be a big problem as the loads would be transferred to the sides, allowing the door to slide easily. Silicon spray (being a Yachtie were we use this stuff everywhere), we now use silicone spray on all our windows in our 1930 home and the windows glide across with one finger before they used to tilt when trying to open them. I would place the door head up to line up with the others and one thing you might consider is placing a window seat, (rebate the bottom channels into the window seat) and have the window seat in and out, place a cushion over the entire seat, should be fantastic and if the deck is built, than no balustrade is required. If it is a stacker slider, i would do the seat for the entire length. So instead of looking a bit funny they will think it was supposed to be like that. We should all think outside the square more often. RAM

Hi there, I'm no 'expert' however... French doors, are they going to be able to open back on themselves? As I notice that off your kitchen in the wee corner - when the doors are open this will become unusable space (as they will need to be fastened / hooked somehow to stay open). I would also suggest a cavity slider for your pantry (unless your plans already show this, am not sure), rather than a door or just an opening. Our tv also sits in a similar position - we get quite a lot of glare through our large windows - we ended up tinting them 1 shade darker than normal (when we double glazed). And I still haven't worked out if I want blinds or come form of curtain. Good luck with it all.

Errol, we also have an 80s brick home with similiar window placement. When the budget allows we would like to change the larger of the windows (what would be your existing sliding door in your layout) to french doors to open out to our deck area. We would keep the window in meals area as a window as there is not enough circulation space inside to use a door, even a sliding door. For us, french doors would work best as they can fold back relatively flat against the wall when opened, while bifold doors would stick out too far. We will also replace the old diamond grill screens with crimsafe which aren't as ugly! Why is it that houses in home decorating magazines never have screens? Would love the aesthetics of no screens but in Qld screens are essential. We don't have the issue with lack of light inside that you do (and we love our light-filled open plan space so skylights might be a good investment for you), but the downside is our outdoor area is underutilized as is in full sun most of the day and is uncovered. Could you change your outdoor roof to a vergola system or something more transparent to get more light inside?

OP, you should also consider energy efficiency & comfort. It's great that you appear to have north facing living areas (with a high proportion of glazing facing this direction). But looking at the elevation picture, it appears you may have too much glass. Overglazing can result in a home that becomes uncomfortably hot, even in winter! This is very dependent on your location & climate. Cooler climates need more exposed north facing glass, & exposed thermal mass (concrete or masonry) to absorb that solar radiation. Warmer climates require less exposed north facing glass & thermal mass, particularly hot humid climates, where exposed thermal mass can be very detrimental. In these climates it's important that northern glass is shaded, even in winter of glass areas are too high. As there's no floor plan, & you haven't mentioned your location, it's hard to tell if you've overglazed with exposed northern glass. Read the following site, & consider your glazing to floor area & glazing to mass ratios. http://yourhome.gov.au/passive-design/thermal-mass