This summer, we had no problems without air conditioning. It was usually 21/22 degrees in the house, and when it was warm, it was 23 and once even briefly 24 degrees. However, manual night ventilation - is it just as effective for you? We live in the refrigerator of Bavaria when it comes to solar radiation. The ventilation automatically shuts off as soon as the outside air is above the target indoor temperature. During the week, when hardly anyone is home, this is great. On weekends, you turn on the ventilation or open the windows at midday; it just becomes stuffy. Your house has an active cooling option. In an energy-saving regulation house, once the heat is inside, it is no longer so easy to get it out.