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.