Of course if the builders were required to build new houses to a decent level things would b e better. I have lived abroad and travelled a lot. One of the best things is to have real double glazing with a big gap between the two panes of glass. This helps to keep back noise too. I also often had good outside wooden blinds that you lowered to suit yourself. Too much sun, lower to keep the rooms cool and the glare out. cold windy winter night, drop them down to give yourself another layer of protection and warmth, . These days I think no planning permission should be given for housing unless there is good solar panel all over the roof, and consideration for the air flow inside the house, so that you can make the most of cool air or heat at appropriate times. We had , for winter, a calor gaz heater, with wheels so that you could move it to suit yourself, you had a choice of 1 2 or 3 bars on and it could heat up very quickly.
Simpler ideas that I have used for years that can help . So dont throw out the old hot water bottle, but use it in the summer. Fill with very cold water and some ice cubes. Put on the floor and as and when take your feet from your sandals or slippers and place on bottle. Lovely and cool. I always , in the summer time pack a clean white flannel, that I have put into cold water and ice and squeezed out lightly, into a good plastic bag. This goes in my bag and is available at any time to wipe hands and faces and put to cool the neck. Can be used with no problem on plane, bus or train etc. and can be refreshed in a washroom later. At night in the heat, I also take the cold water bottle and the cool flannel to help get off to sleep and arrange the interior doors to give some air flow. Very simple but they work. When I lived in Syria had no aircon in myh flat but there were tiles which helped etc. I dont like noisy aircon and nor do I like the bills!!
I think we need one for upstairs too. We are in a new build and it is so hot upstairs