This is incredible. Where are your stockists?

Bit of a circle thing, the engineer will have trouble commenting on what you plan to do without drawings of the existing and proposed. Never met an engineer who could not work their magic on any structure, but there will be simple and cheaper methods and then there can be some super expensive ones. Builders and engineers should be communicating as well. If i were you, i would have identified a builder, get a good architect to work with you, your budget, the builder and engineer, and town planner if this requires DA approval. Overshadowing is the shadow your structure casts on the neighbors property. Overlooking is when they can see into your property, some councils have means to prevent this and the last to build normally has to screen their windows to prevent overlooking, some require only high windows, not all councils and not all property sizes will be affected. If the architect draws in a 3D package it is a simple matter to show you where the shadows land at any time and day of the year, based on you address. If allowed to build that top story, they can show you if you shade your pool. This is a big investment from you, most likely you would be living with the results for years, i would imagine that you would want the best outcome for your family, and to engage professionals would be the way to achieve those outcomes. Thoughts and ideas from forums like this are great, but sometimes they are not aware of the outcomes of comments which might affect your whole project, and councils around the country all have different requirements. Check and check again. What is allowed in Brisbane with height and upper floor window sizes on smaller blocks, will not be allowed in Melbourne, or Sydney councils. Shadowing while really not an issue in Brisbane, will be a huge issue in Melbourne, so get a local team. Ros

It really comes down to insulation, orientation, windows and cross-flow ventilation. Possibly your high-set house doesn't have the same ceiling insulation, or has more western windows, than your previous house. When considering your new home the orientation is the most important factor when considering how hot (or cold) it is. If you are in a hot climate then large sliding windows (not awning) and an open floorplan are also important if you want to get the benefits of cross-flow ventilation. With global warming our summers are only going to get more extreme so it is a good idea to consider how well a new house will perform with hot days when looking to buy. Best of luck, Dr Retro of Dr Retro House Calls

Landscaping is for long term. Lots of people use plants like neighbors begone to quickly hide neighbours, but a canopy tree or two may look better longer term and filter rather than fully block views so you don’t feel hemmed in. Weeding and maintaining garden beds can be just as high a maintenance as lawns. Really sit in your favourite spots and think about what you want to see and visualise how you would use the space, now, in 5 and 10 years. Put bins and hoses around to help envision plan. Think where does the sun hit the yard at diff times of day and year, how will it be affected by screening etc. walk around your neighborhood and take pics of plants the At grow well and you like. More helpful if in flower for identification. Then list your values and priorities for an expert to consider, more important than any concept plan. This will also help staging for your budget