There is a reason why A/C is much less popular in Europe than in the States: It's simply not as useful if the house stays cool on its own if you lower the blinds and only open the windows briefly to let in fresh air.
There is a reason why A/C is less popular in Europe than in the States, but it's not that. Correct me if I'm wrong, but I don't think there's any part of Europe that regularly gets temperatures upwards of 100 degrees Fahrenheit (38 degrees Celsius) on several days of every summer. Much of the southern United States does, and that's why A/C is a necessity there. Just changing the building material won't cut it, even if it does improve the cooling situation.