Climate change can mean more extreme temperatures. We need to be able to keep warm, and keep cool. The better you insulate a house, the better it can keep cool after cooling down at night, and keep the heat out when you do use air conditioning.

One thing helping with this is airtightness, and MVHR. Couple that with good insulation (keeps hot out, as well as in), and things like shades above south facing windows to block the sun when it's at it's highest/hottest, and we see a lot of improvements. MVHR especially helps to distribute heat between rooms, and provide fresh air without completely heating/cooling the house.

Thought for a while i need some kind of window shutters. Seems obvious to stop the sun getting to the windows keeps house cooler

Houses, public and commercial buildings, everything needs to be rethought. Currently visiting the UK from a much warmer and more humid climate in the states. It's bizarre that it's pleasant outside but almost uniformly uncomfortably warm (and frankly, more important humid) inside. Out hotel room is supposedly air conditioned but stays a uniform 25-26c no matter what the thermostat is set on. It's "working appropriately" according to management and their 3 different maintenance staff that have "adjusted" it, but it is not handling the humidity well. The only saving grace is one of the windows will open ~6in to allow us to open it at night. The bigger picture is how this heat and humidity are going to effect the buildings and their contents. It doesn't take all that long a time for humidity and high indoor temps to allow serious mold issues to start taking hold. People forget the original use of ac wasn't for human comfort but to keep goods (specifically paper) dry so it didn't curl and become unusable by a printing company.