Indeed an interesting thread an I must admit that I've been going cross-eyed extracting as much information from your two images as I can. A very challenging dilemma. I can't speak for the glazing. It's not my area of expertise. I'm inclined to agree with other comments in this thread re leaning towards internal window treatments. The long raking window at top presents special challenges and as Envirotecture has indicated it would meaning being open to the consideration of framing your view somewhat. Here are some ideas which might be worth considering. 1. A fixed curtain for the upper raking window. Given the room is very much about light, a sheer, though not providing the same insulating properties as curtains or heavier drapery, would nevertheless, provide some insulating benefit from the air-gapping effect. A fixed curtain (sheer or otherwise) is likely to be one of the cheaper components in the options I'm listing. 2. It's hard to tell from the images how much more the 'conventional' rectangular space beyond the couch extends. Assuming it does not extend the entire length of the side of the house you have a number of options available to you here. Options which could Include Soft Roman Blinds fronting on sunscreen roller blinds. Pelmets would provide substantive insulating benefits, but it is difficult to see from the image whether they would suit, and whether you would have sufficient height, or 'any height' above that window in which to mount them so as to minimise the loss of window view due to the stacking up of the Roman. The sunscreen rollers are less problematic in that regard and provide some insulation while still allowing light when the Romans are not lowered. If opting at any stage for Romans, ensure they are properly lined with pre-stiffened Roman Lining which provides better insulation, but almost more importantly, will not sag over time such is the case with many Romans that are lined with much cheaper curtain lining which is not pre-stiffened and does not afford the same degree of insulation. 3. Along the main alfresco expanse where the table is located, and under the previously proposed location of the fixed curtains along the raking window, a motorised or hand traversed S-Fold or Wave curtain fronting, yet again, more thermal sunscreen roller-blinds could present an attractive modern look in keeping with the modern style of the room and house. Of course, an issue is going to be stack-back when the curtains are open, however, the double layered protection of both a Wave or S-Fold curtain and Roller Blinds will provide superior insulating benefits to tinting throughout the year (not just summer) imho. 4. Other ideas include Plantation Shutters across the raking/eve window above. I doubt very much that plantation shutters would work along the lower 'framed' area as the stack-back effect if bi-fold, or loss of view if sliding, would be too much of a sacrifice, let alone the additional consideration of the cost of such treatment used so extensively. Although, the window treatments i have suggested for possible consideration do not necessarily offer optimum insulation (eg the exclusion of pelmets or use of heavy lined drapery), I believe that you there would be some offset in terms of a positive ROI over time due to the savings you will reap on your heating/cooling bills. I'm in Melbourne which is marginally warmer, and without adequate insulating window treatments, the heat loss through the glass is substantial and the heating/cooling bills frightening. 5. That's a hell of a lot of glass to treat whether you opt for a glazing solution which will provide primary benefit during the summer or conventional internal window treatments - whether drapery or blind. Either way the solution is likely to be costly. To keep the cost down you could always consider high quality Thermal Verticals which can come in a variety of slat sizes colours and textures and provide substantive savings over the Wave or S-fold solutions with less stack-back loss. Once again ensuring you purchase high quality verticals that will hold up to the Australian sun over the long haul is important. The cheaper stuff might look good but you'll be picking slats off the floor within 5 years if you are not careful. Here is an image from one of our own projects where high quality 'chain-less' verticals were used to cover large expanses of glass throughout the house in combination with thermal roller blinds. Of course, this treatment or the use of Wave/S-fold curtains would only provide part of the overall solution you require. 6. The only solution I didn't yet mention is the use of folding arm awnings. While they would provide benefits during the summer, they would be more than likely at the expense of your expansive view (or part thereof). Quality awnings whether manually operated or motorised are also costly. The only other comment I might make is that internal blind and curtain window treatments provide you with a high degree of flexibility. Romans, for example work well in combination with many other window treatments, either along side them, or in combination with each other in the context of the same window. The same can be said for the other treatments I have mentioned. The internal window treatments suggested can also facilitate the ability to support a style transition from one room or area to the next. - An important consideration if the house is of a uniform style throughout and you are wanting to 'mix it up a bit' or transition to styles that vary yet compliment the primary style or look you may have throughout the house. I'm sorry, it is difficult offering suggestions based on your two images, even though they are of good quality and detailed. I don't envy you with this 'design dilemma' ... though it certainly gets my vote as one of the more challenging ones I have seen in recent times, and in an area/topic where I felt I could contribute.

As a window tinter I could suggest installing a coloured window film from the deco range with choices that range from opaque to total block out . With so many colours to choose from that you may be able to either change the overall colour by installing a translucent type of a different colour that will change the overall resultant colour or use a total block out film . ( you will need to check to see if the glass is flat an smooth for this though) If it's only a small job then you can try an install these films your self rather than changing the glass . A local glazier may have some glass off cuts that you may get free or cheap to reglaze yourself . (PROTEK window tinting & blinds )

Hi lurchsmum Wow. Thanks for sharing. We're aiming to get uPVC double glazed windows and also have tiled floors. It is good to know about this in advance. Are your double glazed windows especially tinted? With low-e glass? Or something else? Or are they just 'standard' windows? That would have been quite a shock. Hope you feel better about it now.

We have just gotten our first quote to tint our windows. Got the same issue plus I am wanting to reduce the heat that comes through as well. They say that without loosing the light that comes through you can get up to 55% heat reduction. Sounded good to me They have other films too where you can get UV protection but loose some of the light. Keen to hear from people who had their windows tinted. Worked out about 85/m2 installed for us in case you wonder.